COMP 4320 - Final Exam

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The key reason(s) why digital signals must be modulated before sent is (are):

A medium treats differently signals using different frequencies

Consider this code snapshot: String str = new String("CD456"); byte[] a = str.getBytes("UTF-16BE"); The content of a[0] is ___________.

Consider this code snapshot: String str = new String("CD456"); byte[] a = str.getBytes("UTF-16BE"); The content of a[2] is ___________.

Consider this code snapshot: String str = new String("CD456"); byte[] a = str.getBytes("UTF-16BE"); The content of a[4] is ___________.

Consider a 4-KHz noiseless channel. The sender is using the vocabulary set S to communicate. S = {apple, banana, pear, mango}. The maximal bit rate is _________ bps.

16000

The network ID of IP Address 164.200.40.13 is _________.

164.200.0.0

The network ID of IP Address 164.200.40.13/22 is _________. 164.200.0.0 164.200.32.0 164.200.64.0 164.200.40.0 None of these answers

164.200.40.0

The network ID of IP Address 164.200.40.13/29 is _________.

164.200.40.8

The network ID of IP Address 172.20.14.53/28 is _________.

172.20.14.48

The network ID of IP Address 172.202.100.3 is _________.

172.202.0.0

The network ID of IP Address 172.202.100.3/20 is _________.

172.202.96.0

The subnet mask of IP Address 164.200.40.13/22 is _________. 255.255.252.0 255.255.248.0 None of these answers 255.255.0.0 255.255.240.0

255.255.252.0

The subnet mask of IP Address 63.20.140.153/26 is _________.

255.255.255.192

The subnet mask of IP Address 200.20.14.53/27 is

255.255.255.224

The subnet mask of IP Address 200.20.14.53/27 is _________.

255.255.255.224

The subnet mask of IP Address 164.200.40.13/29 is _________.

255.255.255.248

Consider a 4-KHz noisy channel with a 20 db SNR. The sender is using the vocabulary set S to communicate. S = {apple, banana}. The maximal bit rate is _________ bps.

26,633

A user types the command "arp -a" on the console of the machine csexmac161engauburnedu. The arp command displays (see picture) the content of the ARP cache of the machine csexmac161engauburnedu. Suppose that IP on this machine must send a packet to the interface with IP Address 192.168.1.144. When IP asks ARP for the address 192.168.1.144, ARP will return the MAC address ________________.

2:f:b5:13:2:ca

Check all that apply. This question is related to the performance evaluation of the Stop-And-Wait protocol on an error-free channel. Refer to the figure to answer. Within the same cycle, the variable T can be approximated as ________________ assuming that we neglect the time to process a received packet and the time to transmit an ack.

2Tp + Tr Tp + Tr + Tp

A class B network can assign unique addresses to up to _______________ hosts.

2^16-2

A hamming code of distance 4 can detect up to _______ corrupted bits in a received word..

Consider the following code C to encode this vocabulary L, M, N, and O: L : 0000 0000 M: 0100 0011 N: 1011 0101 O: 1111 1010 The Hamming distance of Code C is _______

Consider these two words: W1 = 1001 1000 W2 = 0101 1010 The Hamming distance between W1 and W2 is _____.

The email architecture involves ________ main operations.

Match these encoding schemes for baseband transmission from the most robust to the least robust. Assign 1 to the most robust encoding scheme and 99 to the expressions that are not encoding schemes for baseband transmission. Non-Return to Zero (NRZ) Non-Return to Zero Invert (NRZI) Manchester Amplitude Shift Keying (ASK) Phase Shift Keying (ASK)

3 2 1 99 99

Consider this code snapshot: String str = new String("CD456"); byte[] a = str.getBytes("UTF-16BE"); The content of a[9] is ___________.

Match each protocol with its protocol number used in the protocol (number) field in the IPv4 header. TCP UDP ICMP Ethernet Wifi (IEEE 802.11) Bluetooth

6 17 1 Not Applicable Not Applicable Not Applicable

Select the best answer. Suppose that we transmit symbols belonging to this vocabulary {A, B, C, D, E, F, G, H}. The baud rate is 2,000 bauds. The bit rate is.

6 Kbps

The length of an IPv4 header is at most ________ bytes.

The subnet mask of network N is 255.255.255.192. This network N can assign unique addresses to up to _______________ hosts.

The network ID of IP Address 63.20.140.153 is _________.

63.0.0.0

The network ID of IP Address 63.20.140.153/26 is _________.

63.20.140.128

The highest UDP and TCP port number is _____

65535

The total length of an IPv4 packet is at most ________ bytes.

65535

Consider this code snapshot: String str = new String("CD456"); byte[] a = str.getBytes("UTF-16"); The content of a[3] is ___________.

Consider this code snapshot: String str = new String("CD456"); byte[] a = str.getBytes("UTF-16BE"); The content of a[1] is ___________.

Consider this code snapshot: String str = new String("CD456"); byte[] a = str.getBytes("UTF-16"); The content of a[5] is ___________.

Consider this code snapshot: String str = new String("CD456"); byte[] a = str.getBytes("UTF-16BE"); The content of a[3] is ___________.

The following frame was "sniffed" off an Ethernet network. Below, we removed the preamble. We use only hexadecimal numbers without using "0x" or "h" symbols. Here is what was collected in network byte order: 08 06 80 35 08 06 76 3E 56 E2 08 00 08 00 32 7F 4C 2D 5C 4B EE DD .... The source MAC address is ___________________.

76 3E 56 E2 08 00

The following frame was "sniffed" off an Ethernet network. Below, we removed the preamble. We use only hexadecimal numbers without using "0x" or "h" symbols. Here is what was collected in network byte order: 76 3E 56 E2 08 00 08 06 80 35 08 06 08 00 32 7F 4C 2D 5C 4B EE DD .... The destination MAC address is ___________________.

76 3E 56 E2 08 00

Consider this network: Hosts A, B, and DNS have MAC addresses Ea, Eb, and Ed, respectively. The bridge cache is as follows: MAC addresses Ports Ea P1 Ed P2 Eb P1 Consider this frame that was just sent (Ignore the number 2 in the "Segment" Column): frameEaEb.png Besides its sender, this frame is seen by Host(s) _____________ .

Consider this network: segment.png Hosts A, B, and DNS have MAC addresses Ea, Eb, and Ed, respectively. The following frame appears on Segment 2: frameEaEb.png This frame is picked by Host(s) _____________ for further processing by the link layer.

The class of IP Address 1.20.140.153 is _________.

The class of IP Address 126.200.40.13 is _________.

The class of IP Address 45.20.14.53 is _________. B C None of these answers D A

The class of IP Address 63.20.140.153 is _________.

Consider this network: segment.png Hosts A, B, and DNS have MAC addresses Ea, Eb, and Ed, respectively. The following frame appears on Segment 2: frameEaEb.png Besides its sender, this frame is seen by Host(s) _____________.

A DNS

Consider this network of routers A, B, C, and D that are using Distance Vector Routing. Assume that all routers are turned on at the exactly same time 0. At time 0, the routers know only the cost to reach their immediate neighbors. At time 0 (Round 0), all routers send their distance vector to their immediate neighbors. Each 30 seconds, a new round of exchanges occurs (Round 1, 2,...). Fill in the table below with the distance vector that Node A sends its neighbors on Round 1. If the distance is not yet known, fill in with the value 99.

A = 0 B = 1 C = 2 D = 2

The Internet is a network covering typically _____

A planet

A wide area network (WAN) is a network covering typically _____

A planet Country Continent

In the OSI reference model, this layer is an intruder (i.e., it does not belong within this list of options).

Application ------------------------------------------ Physical None of the above Network Application Data Link

Apart the difference in the layers where they perform, DNS is a service most similar to the _________ service. DHCP IP none of these answers ARP NAT

ARP DELETE

In the TCP/IP Reference Model, your laptop uses this (these) layer(s) when you are configuring your wireless router/access point using a browser.

Application Data Link / Link Transport Internet / Network

In the OSI Reference Model, your laptop uses this (these) layer(s) when you are configuring your wireless router/access point using a browser.

Application Presentation Internet / Network Physical Session Transport Data Link / Link

In the OSI reference model, these layers are active only on devices at the end points of a conversation.

Application Transport Session Presentation

In the OSI reference model, the [name1] layer receives service directly from the presentation layer.

Application

In the OSI reference model, this layer is the closest to the "user".

Application

In the TCP/IP Reference Model, your wireless router/access point uses this (these) layer(s) when you are configuring it using a browser.

Application Data Link/Link Transport Internet/Network

These layers are part of the OSI Reference Model.

Application Presentation Session Transport Network Data Link Physical

In the TCP/IP Reference Model, these layers are mostly implemented by software on most hosts (clients or servers).

Application Transport Internet / Network

The TCP/IP Reference Model includes this (these) layer(s).

Application Transport Link

In the TCP/IP Reference Model, your wireless router/access point uses this (these) layer(s) when you are configuring it using a browser.

Application Internet/Network Transport Link

A receiver receives the following frame using Flag Bytes with Byte Stuffing: FLAG ESC ESC Y X ESC FLAG R FLAG where letters A-Z represent bytes. The payload, i.e., the message, sent (without the stuffing if any) inside this frame is _________.

ESC Y X FLAG R

This (These) protocol(s) are used at the Link layer in the TCP/IP Reference model.

Ethernet IEEE 802.11 DSL (multiple versions - may only have one of these options listed)

When a packet is successfully delivered without any issue, this (these) protocol(s) would not likely be involved.

ICMP

IP (Internet Protocol) provides service directly to these protocols.

ICMP TCP UDP

Check all that apply to IP addresses

IPv4 has 32 bits it uniquely identifies a network interface

IP addresses

IPv4 has 32 bits addresses

Check the protocol(s) that belong(s) to the network layer

IPv6 IPv4

In the TCP/IP model, UDP uses this (these) protocol(s) at the network (Internet) layer.

IPv6 IPv4

The following frame was "sniffed" off an Ethernet network. Below, we removed the preamble. We use only hexadecimal numbers without using "0x" or "h" symbols. This frame certainly carries as payload _______________. 08 06 80 35 08 06 76 3E 56 E2 08 00 86 DD 32 7F 4C 2D 5C 4B EE DD

IPv6 packet

In the TCP/IP reference model, IP belongs to the _______________ layer.

Internet

The TCP/IP Reference Model includes namely this (these) layer(s). Internet Session Transport Link Network

Internet Transport Link

In the TCP/IP model, an instance in the transport layer wants to send a data unit m. The first header added to m will be a header belonging to the ________ layer.

Internet (Network)

In the TCP/IP Reference Model, a router uses this (these) layer(s) when carrying a conversation.

Internet / Network Data Link / Link

In the OSI Reference Model, these layers are mostly implemented by software on most hosts (clients or servers). Physical Link Application Session Internet / Network Transport Presentation

Internet / Network Session Presentation Application Transport

In the OSI Reference Model, an L3 switch uses this (these) layer(s) when carrying a conversation.

Internet / Network Data Link / Link Physical

In the OSI Reference Model, your wireless router/access point uses this (these) layer(s) when you are configuring it using a browser.

Internet / Network Session Physical Presentation Application Transport Data Link / Link

In the TCP/IP Reference Model, the youtube server uses this (these) layer(s) when streaming to you videos.

Internet / Network Transport Application Data Link / Link

In the context of computer networks, IP stands for ______________.

Internet Protocol

In the TCP/IP Reference Model, your wireless router/access point uses this (these) layer(s) when it is forwarding your streaming traffic. Transport Application Session Internet/Network Presentation None of these answers Link

Internet/Network Link

This issue is not a network software issue

Memory footprint --------------------------------------- Scalability None of these answers Confidentiality or authentication Memory footprint Routing

Check components that are part of the email architecture presented in class..

Message Transfer Agent Mailbox

A host H has IP address A represented in dotted-decimal as 200.204.14.65. Select the instruction that computes the network ID NID of IP Address A.

NID = A & 0xffffff00

A host H has IP address A represented in dotted-decimal as 200.204.14.65/26. Select the instruction that computes the network ID NID of IP Address A.

NID = A & 0xffffffc0

A host H has IP address A represented in dotted-decimal as 128.204.14.65/28. Select the instruction that computes the network ID NID of IP Address A.

NID = A & 0xfffffff0

In this (these) distributed routing protocols(s), each node communicates will all other nodes about its distance to its immediate neighbors only.

OSPF

This (These) protocol(s) use(s) link state routing or one of its improved variants.

OSPF

__________________ is an interior gateway protocol using ____________ routing.

OSPF: Link State

Check all applications that use TCP. POP3 DNS Trivial FTP None of these answers HTTP ssh

POP3 HTTP ssh

Check the application layer protocol(s) used for the delivery of an email from a Message Transfer Agent to a Receiver User Agent.

POP3 IMAP

__________________ is an interior gateway protocol using ____________ routing. OSPF:Path Vector RIP: Distance Vector None BGP: Path Vector IGP:Distance Vector

RIP: Distance Vector

Since the preamble is removed, look at bytes 13 and 14. These will determine payload (google EtherType) 0x0800 - IPv4 0x86DD - IPv6 0x0806 - ARP 0x8035 - RARP

Check all features/services SMTP allows/offers.

Used to transfer data in plain from the Sender User Agent to the Message Transfer Agent Used to transfer data in plain from to a Message Transfer Agent to a Message Transfer Agent Transfers plain ASCII text (May not have all listed)

A medium impacts a signal it carries in different ways. In general, an optical fiber __________ a signal that is a mix (sum) a signals using different frequencies.

attenuates distorts delays

A medium impacts a signal it carries in different ways. In general, a coaxial cable __________ a signal that is a mix (sum) a signals using different frequencies.

attenuates delays distorts

A medium impacts a signal it carries in different ways. In general, a twisted pair cable __________ a signal that is a mix (sum) a signals using different frequencies.

attenuates delays distorts

Fill multiple blanks. These techniques are used for framing: _____, flag _____ with byte stuffing, flag bits with _____ stuffing, and _____ code violations.

byte count bytes bit physical layer

Consider the method DatagramPacket(a,b,c,d). The type of the paramtet a is _____ assuming that d is a port number.

byte[]

Check all features that TCP offers while UDP does NOT.

congestion control error correction (retransmissions) Reliable in-order delivery Flow control (Not all options may appear)

Suppose that a function f(x) reaches its maximal value for some value x max. If x max exists then x max is the solution of the equation ________________.

d f ( x ) d x ( x max ) = 0d f ( x ) d x ( x max ) = 0

The data link layers has two sublayers: _______ link and _______ control

logical medium access

In the OSI reference model, this sublayer provides service directly to the network layer.

logical link

Collision Detection is used to _______________

minimize the time wasted by collisions

Complete the words (do not repeat the first letter(s) already provided) The functions/services offered by the data link layer are: 1) F___________ 2) E___________ 3) Fl___________

raming; rror control; ow control

Based on the textbook, broadcast channels are sometimes referred as ______________ channels

random access multiaccess

Broadcasr channels are sometimes referred to as

random access channels multiacess channels

The Open Shortest Path First protocol (OSPF) uses _______ as its "transport" protocol.

raw sockets

For DNS, the top-level domains are run by __________________ appointed by ICANN.

registrars

In general, an HTTP _________________ is longer than a(n) ________________.

response: HTTP request

Layered design consists of ________________.

restricting communications to adjacent or peer layers layers hiding details from each other dividing a complex task in multiple subtasks

Consider a sender and a receiver connected using a "lossy" (loss-prone) channel. Check all required countermeasures at the sender to insure reliable communications.

retransmission timeout

Check the (kind of) delay(s) that are in general random. queue time bit rate time None of these answers propagation time total time transmission time

queue time total time

Fill in the blanks. Some words are hinted by the first letter. Do not repeat the first letter. The logical link sublayer provides three services: F_____, E_____, and F_____ control

raming rror control low

Consider a sender and a receiver connected using a real life channel. Check all required countermeasures at the sender to insure reliable communications

retransmission timeout

Check all that apply. During the lecture, we encoded the three boolean members single, rich, and female using one byte b using the following rules as illustrated by this figure: bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 0 0 0 0 0 female rich single - bit 0 is the least significant bit. bit 0 is set to 1 if the friend is single. - bit 1 is set to 1 if the friend is rich. - bit 2 is set to 1 if the friend is female. Suppose that after encoding the three boolean members single, rich, and female of a friend f into a byte b, we get b = 0x3. Check all that apply about the friend f

rich single

rich single female

On WANs, switches are called ___________.

routers

In the IPv4 header, the TtL (Time To Live) is related to the maximum number of _________________.

routers the packet can traverse

These functions services are offered by the network layer.

routing addressing

Designs that continue to perform well when the network gets large are said to be ___________.

scalable

Flow control insures that a _______ does not overwhelm the ______.

sender receiver

Congestion Control insures that a [Select] does not overwhelms the [Select]

sender, intermediary nodes and receiver

In the OSI reference model, an instance in the presentation layer wants to send a data unit m. The first header added to m will be a header belonging to the ________ layer.

session

The number of layers in the OSI Reference model is ____________ .

seven

Consider a communication over satellite under some drastic adverse magnetic interferences. Under these conditions, it may be better to use ______________ to correct damaged frames. odd parity retransmission None of these answers. even parity some forward error correction technique

some forward error correction technique

The application layer offers in general these services/functions.

specialized services to users that lower layers do not offers addressing/naming

The size of the options field in an IPv4 header is ___________ bytes.

variable

When implementing a connection-oriented service, we use ___________________ to carry messages.

virtual circuits

In the IPv4 header, the Protocol (number) is related to the protocol used by the payload at the__________ layer. Group of answer choices None of these answers network (data) link physical transport

transport

In the OSI reference model, UDP belongs to the ___ layer

transport

In the OSI reference model, an instance in the session layer wants to send a data unit m. The first header added to m will be a header belonging to the ________ layer.

transport

In the OSI reference model, this layer gets service directly from the network layer.

transport

In the TCP/IP model, an instance in the application layer wants to send a data unit m. The first header added to m will be a header belonging to the ________ layer.

transport

In the TCP/IP model, consider an HTTP request m. The first header added to m will be a header belonging to the ________ layer.

transport

When tuned to one channel, check all that apply to IEEE 802.11 (Wifi)

uses a contention based multiple access protocol has in general a lower average time delivery than Token-ring

The subnet mask of IP Address 45.20.14.53/12 is _________.

255.240.0.0

The subnet mask of IP Address 126.204.40.13/13 is _________.

255.248.0.0

The subnet mask of IP Address 191.20.240.213/18 is _________.

255.255.192.0

The subnet mask of IP Address 128.200.104.13/19 is _________.

255.255.224.0

The subnet mask of IP Address 172.202.100.3/20 is _________.

255.255.240.0

The subnet mask of IP Address 164.200.40.13/22 is _________.

255.255.252.0

In the OSI reference model, adjacent layers use an [name1] to communicate.

Interface

a message m is divided and sent using k packets P i. let m e r be the message error rate. Check all correct equalities

(1 - per)^k = 1 - mer

Let us use the following notation: - P s is the packet size (number of bits in P) - b e r be the bit error rate. - p e r is the packet error rate Assuming that b e r ≪ 10 − 6, check all correct approximate equalities. per≈(1−ber)PSper≈(1−ber)PS None of these answers. (1−ber)^PS≈1+PS.ber per≈(1−ber)^PS−1 (1−ber)^PS≈1-PS.ber

(1−ber)^PS≈1-PS.ber

Check all weaknesses of static allocation of a broadcast channel with capacity C assuming there are n stations with n ≥ 2.

(5/10) The number of available channels cannot be easily decreased.

In the TCP/IP Reference Model, your wireless router/access point uses this (these) layer(s) when it is forwarding your streaming traffic.

(Partial 3.13/6.25) Data Link / Link Internet / Network Physical

This question is related to the performance evaluation of the Stop-And-Wait protocol on an error-free channel. Refer to the figure to answer. Let P sbe the packet size in bits and b r be the bit rate in bits/s. Assuming that we neglect the processing time of a received packet and the transmission time of an acknowledgement, the efficiency is equal to _______________.

(Ps/br)/(2Tp+Ps/br) (Throughput/bit rate) by definition Tr/T Tr/(2Tp + Tr) Tr/(2Tp + Ps/br) (Ps/br)/T

Check all that apply. The function call Socket is called by a ________________. -Java TCP Client to initiate a connection with a TCP server -None of these answers -Java TCP Client to exchange data with a TCP server -Java TCP server to initiate a connection with a TCP client -Java TCP Server to exchange data with a TCP client

***(maybe) java TCP Client to intiaiate a connection with a TCP server java TCP server to exchange data with a TCP client

The function call DatagramSocket is used by a

- Java UDP Server to establish a UDP socket - Java UDP Client to establish a UDP socket

Check all that apply to UDP:

- UDP offers a minimal service to the application layer - uses a checksum to detect corrupted datagrams

Consider a system with 4 stations X,Y, Z, and W that use CDMA. These four stations use the chip sequences x, y, z and w that are all mutually orthogonal. Stations X, Y, Z, and W send 0, 0, 1, and 0, respectively. If S is the resulting signal S then x.S = ________.

-||x||^2

A (TCP or UDP) port ____.

- is a 16 bit number - varies from 0 to 65535

Check all that apply. The call Socket in Java performs these actions. -it adjust the queue of incoming requests -it creates a socket -None of these answers -it may bind to a port -it connects to a server

- it may bind to a port - it connects to a server - it creates a socket

Check all that apply about TCP or UDP port numbers:

- they are 16 bit numbers - TCP and UDP ports are independent from each other - they range from 0 to 65535

Check all that apply to the OSI reference model.

-It is a good education tool to understand networks -It is an international standard of networks -It is a thorough representation of computer networks

Check all that applies to the Shannon's Theorem.

-Its limit is different for different media -It limits the baud (symbol) rate -It limits the bit rate -It applies to noisy channels

Check all true statements about the OSI reference model.

-The physical layer will be active on ALL nodes of a conversation. -The network layer is a point-to-point layer. -The transport layer is an end-to-end layer

The key objectives/benefits of a layered design are:

-The serviced layer does have to worry about the details belonging to the serving layer (service provider) -Simplify a complex function/service by partitioning it into smaller functions

Bluetooth is a technology that could work well to connect ______

-a central unit (computer) with the standard inputs/outputs -Wireless speakers to an entertainment center -Audio system to your cellphone in a car

The physical layer provides this (these) service(s).

-deals with the mechanical/electrical characteristics of the transmission medium used. -transmits on channels raw bits.

The objective(s) of the physical layer is (are) to ______________.

-deploy transmission techniques to optimize the use of a medium -specify the electrical and mechanical specifications to establish communications -send as many bits per second as possible without corruption or loss

The data link layer provides this (these) service(s).

-detects transmission errors. -controls the access to the medium.

Check all that apply. The call ServerSocket in Java performs these actions. -it binds to a port -None of these answers -it creates a socket -it may adjust the incoming queue -it accepts incoming requests

-it binds to a port -it creates a socket -it may adjust the incoming queue

The delay for a frame from sender to receiver depends on the ______________.

-propagation speed -distance between the sender and the receiver -bit rate -transmission medium -frame size

Consider a system with 4 stations X,Y, Z, and W that use CDMA. These four stations use the chip sequences x, y, z and w that are all mutually orthogonal. Stations X, Y, Z, and W send 0, 0, 1, and 0, respectively. The resulting signal S on the medium is equal to ______.

-x-y+z-w

-||y||^2

Consider a system using a frame size equal to 1500 bytes. The bit rate is 1.2 Mbps. Assume that the unit used to measure time is equal to the time T r to send a frame. If we use the unit T r as unit, then 0.5 ms = _______________ T r.

...

Consider a system using a frame size equal to 1500 bytes. The bit rate is 12 Mbps. Assume that the unit used to measure time is equal to the time T r to send a frame. If we use the unit T r as unit, then 1 s = _______________ T r.

...

A 125-byte frame is sent at a bitrate of 10 Mbps over a copper cable 1000 kms long. Recall that a copper cable has a propagation speed about 2/3 the speed of light. The transmission time is equal to _________ s.

.0001

A 125-byte frame is sent at a bitrate of 1 Mbps over a copper cable 2000 kms long. Recall that a copper cable has a propagation speed about 2/3 the speed of light. The propagation time is equal to _________ s.

.01

For DNS, these domain names are generic . .com .edu .us .net None of these answers .museum .org

.com .edu .net .org .museum

For DNS, these domain names are generic .

.net .museum .org .com .edu

The objective is to find the number of ARP requests that will appear on Segment 2 as a result of the actions of ONE user. Read carefully the scenario below. Consider this network: segment.png The IP and MAC addresses are on this table: Host Names A B DNS IP Addresses 128.194.45.110 128.194.45.93 128.194.45.254 MAC Addresses EA EB ED We assume that 1) all hosts on this network are running correctly and that Telnet accepts connections on each host. 2) Initially, the ARP cache of the DNS host is empty while the ARP caches for the rest are as follows Host A 128.194.45.93 EB Host B 128.194.45.110 Ea 3) The user types on Host A the command "Telnet 128.194.45.93".

The objective is to find the number of ARP requests that will appear on Segment 2 as a result of the actions of ONE user. Read carefully the scenario below. Consider this network: segment.png The IP and MAC addresses are on this table: Host Names A B DNS IP Addresses 128.194.45.110 128.194.45.93 128.194.45.254 MAC Addresses EA EB ED We assume that 1) all hosts on this network are running correctly and that Telnet accepts connections on each host. 2) Initially, the ARP cache of the DNS host is empty while the ARP caches for the rest are as follows Host A 128.194.45.93 EB 128.194.45.254 ED Host B 128.194.45.110 EA 3) The user types on Host A the command "Telnet 128.194.45.110".

The objective is to find the number of ARP requests that will appear on Segment 2 as a result of the actions of ONE user. Read carefully the scenario below. Consider this network: segment.png The IP and MAC addresses are on this table: Host Names A B DNS IP Addresses 128.194.45.110 128.194.45.93 128.194.45.254 MAC Addresses EA EB ED We assume that 1) all hosts on this network are running correctly and that Telnet accepts connections on each host. 2) Initially, the ARP cache of the DNS host is empty while the ARP caches for the rest are as follows Host A 128.194.45.93 EB 128.194.45.254 ED Host B 128.194.45.110 EA 3) The user types on Host B the command "Telnet 128.194.45.110".

This question is about how the Internet Protocol (IP) handles a packet P and decides where to deliver it. Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 134.89.200.145. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.145 check if Packet P is for Device D read the routing table ask ARP for a MAC address corresponding to IP Address 131.89.200.145 ask ARP for a MAC address corresponding to IP Address 131.89.200.1 hand Packet P to the appropriate protocol at the transport layer. check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.128

0 1 0 0 0 2 0 0

This question is about how the Internet Protocol (IP) handles a packet P and decides where to deliver it. Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.14.65. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.205.14.65 check if Packet P is for Device D read the routing table ask ARP for a MAC address corresponding to IP Address 131.89.14.65 ask ARP for a MAC address corresponding to IP Address 131.89.200.254 hand Packet P to the appropriate protocol at the transport layer. check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.254

0 1 3 0 4 0 2 5

Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.64.170. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.128 read the routing table ask ARP for the MAC address corresponding to IP Address 134.89.200.54 ask ARP for the MAC address corresponding to IP Address 131.89.200.128 check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.54

0 2 0 0 1 0

Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.65.170. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.67 read the routing table ask ARP for the MAC address corresponding to IP Address 134.89.200.254 ask ARP for the MAC address corresponding to IP Address 134.89.200.67 check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.254

0 2 0 0 1 0

Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.65.175. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. -send Packet P to the device with IP address 134.89.200.54 -read the routing table -ask ARP for a MAC address corresponding to IP Address 134.89.200.254 -ask ARP for a MAC address corresponding to IP Address 131.89.200.54 -check if the IP destination address of Packet P is local -send Packet P to the device with IP address 134.89.200.254

0 2 0 0 1 0

Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.65.175. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. -send Packet P to the device with IP address 134.89.200.54 -read the routing table -ask ARP for a MAC address corresponding to IP Address 134.89.200.254 -ask ARP for a MAC address corresponding to IP Address 134.89.200.254 -check if the IP destination address of Packet P is local -send Packet P to the device with IP address 134.89.200.254

0 2 0 0 1 0

Consider a system using a frame size equal to 1500 bytes. The bit rate is 12 Mbps. Then 0.5 ms =

0.5

This question is about how the Internet Protocol (IP) handles a packet P and decides where to deliver it. Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.64.170. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.128 read the routing table ask ARP for the MAC address corresponding to IP Address 134.89.200.67 ask ARP for the MAC address corresponding to IP Address 131.89.200.128 check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.67

0 2 0 0 1 0

This question is about how the Internet Protocol (IP) handles a packet P and decides where to deliver it. Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.65.170. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.67 read the routing table ask ARP for the MAC address corresponding to IP Address 134.89.200.254 ask ARP for the MAC address corresponding to IP Address 131.89.200.67 check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.254

0 2 0 0 1 0

This question is about how the Internet Protocol (IP) handles a packet P and decides where to deliver it. Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.64.159. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.254 read the routing table ask ARP for the MAC address corresponding to IP Address 134.89.200.67 ask ARP for the MAC address corresponding to IP Address 131.89.200.254 check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.67

0 2 3 0 1 4

This question is about how the Internet Protocol (IP) handles a packet P and decides where to deliver it. Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.64.170. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.128 read the routing table ask ARP for the MAC address corresponding to IP Address 134.89.200.254 ask ARP for the MAC address corresponding to IP Address 131.89.200.128 check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.254

0 2 3 0 1 4

This question is about how the Internet Protocol (IP) handles a packet P and decides where to deliver it. Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.65.159. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.67 read the routing table ask ARP for the MAC address corresponding to IP Address 134.89.200.1 ask ARP for the MAC address corresponding to IP Address 131.89.200.67 check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.1

0 2 3 0 1 4

This question is about how the Internet Protocol (IP) handles a packet P and decides where to deliver it. Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.65.170. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.67 read the routing table ask ARP for the MAC address corresponding to IP Address 134.89.200.54 ask ARP for the MAC address corresponding to IP Address 131.89.200.67 check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.54

0 2 3 0 1 4

0.0001

A 125-byte frame is sent at a bitrate of 1 Mbps over a copper cable 1000 kms long. Recall that a copper cable has a propagation speed about 2/3 the speed of light. The transmission time is equal to _________ s.

0.001

A 1250-byte frame is sent at a bitrate of 10 Mbps over a copper cable 1000 kms long. Recall that a copper cable has a propagation speed about 2/3 the speed of light. The transmission time is equal to _________ s.

0.001

A 125-byte frame is sent at a bitrate of 1 Mbps over a copper cable 1000 kms long. Recall that a copper cable has a propagation speed about 2/3 the speed of light. The propagation time is equal to _________ s.

0.005

0.01

0.1

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". Assume that the generated traffic is Poisson (G = 0.25) and that we are using the transmission time T r as unit. The probability that 1 frame are generated during 0.5 unit time is ______________. Help:

0.1103

A 1250-bits frame is sent at a bitrate of 10 Mbps over a copper cable 1000 kms long. Then the transmission time is _________ ms. Propagation speed on copper is about 2/3 the speed of light. The speed of light is about 300,000 km/s.

0.125

Evaluate the Pure Aloha protocol. Assume Poisson(G=0.75). The probability that 0 frame generated during 2 units is

0.16

Evaluate the Pure Aloha protocol. Throughout S(G.e^-2G) is most equal to

0.18

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". We established that for Pure Aloha the throughput S = G . e − 2 G. S = ___________ for G = 0.5. .

0.18

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". We established that the throughput S (G . e − 2 G) for Pure Aloha is at most equal to ___________.

0.18

We established that for Pure Aloha the throughput S= Ge^-2G. S = ________ for G= 0.5

0.18

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". Assume that the generated traffic is Poisson (G = 0.5) and that we are using the transmission time T r as unit. The probability that 1 frame are generated during 0.5 unit time is ______________.

0.1947

In order to evaluate the Pure Aloha protocol. Assume that the generated traffic is Poisson G=0.5 and that we are using the transmission time T_r as unit. The probability that 1 frame are generated during 0.5 unit time is _______

0.1947

Five senders share a 1 Mbps channel using frequency division multiplexing. Each sender will have a sending bit rate of about ________ Mbps.

0.2

Four senders share a 1 Gbps channel using time division multiplexing. Each sender will have a sending bit rate of about ________ Gbps.

0.25

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". Assume that the generated traffic is Poisson (G = 0.75) and that we are using the transmission time T r as unit. The probability that 1 frame are generated during 0.5 unit time is ______________.

0.26

Evaluate Pure Aloha protocol. Assume Poisson(G=0.25). The probability that 1 frame are generated during 2 units time

0.3

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". Assume that the generated traffic is Poisson (G = 0.5) and that we are using the transmission time T r as unit. The probability that 1 frame are generated during 1 unit time is ______________. Help:

0.3

In order to evaluate the Slotted Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". We established that the throughput S (G . e − G) for Slotted Aloha is at most equal to ___________.

0.37

In order to evaluate the Slotted Aloha protocol. We established that the throughput S(Ge^-G) is at most equal to

0.37

Evaluate the Pure Aloha protocol. Assume Poisson(G=0.75). The probability that 0 frame generated during 1 units is

0.47

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". Assume that the generated traffic is Poisson (G = 0.75) and that we are using the transmission time T r as unit. The probability that 0 frame are generated during 1 unit time is ______________.

0.47

A channel has a capacity of 25 Mbps. Using static allocation, this channel is equally divided between fifty stations. When using its channel, each station will send with bit rate _________ Mbps.

0.5

A UDP port number has _______ bits

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". We established that the throughput S (G . e − 2 G) for Pure Aloha is maximal for the value G = ___________.

0.5

A sender and a receiver are using a 100 km copper cable to communicate. The propagation speed is about 2/3 the speed of light. They use stop and wait protocol. The frame size is 500 bytes. The bit rate is 250 Kbps. The propagation time is _____ ms. The transmission time is _____ ms. The throughput is _____ Kbps. The efficiency is _____ .

0.50 16.00 235.29 0.94

0.50 16.00 235290.00 0.94 Could not be 235290. Above question was in Kbps, this is in bps. Could have decimal, IDK

Evaluate the Pure Aloha protocol. Assume Poisson(G=0.25). The probability that 0 frame generated during 2 units is

0.6

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". Assume that the generated traffic is Poisson (G = 0.25) and that we are using the transmission time T r as unit. The probability that 0 frame are generated during 2 units time is ______________. Help:

0.6

Evaluate Pure Aloha protocol. Assume Poisson(G=0.5). The probability that 0 frame are generated during 1 units time

0.61

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". Assume that the generated traffic is Poisson (G = 0.5) and that we are using the transmission time T r as unit. The probability that 0 frame are generated during 1 unit time is ______________.

0.61

Check all techniques we studied earlier that can in general be used for detecting and correcting up to one corrupted bit.

0/12.5 adding a parity bit Hamming codes with distance 2 crossed parities

This exercise is about framing. The following character encoding is used in a data link protocol: X: 01000111 Y: 11110111 FLAG: 01111110 ESC:11100111 Show the bit sequence transmitted (in binary) for the four-character frame X Y ESC FLAG when "flag bits with bit stuffing" is used. Pay attention to the order. Fill in the following 8-bit groups. Some groups at the end may have less than 8 bits. If the group is empty, fill it with "-" (ONE minus character).

01111110 01000111 11011011 11101001 11011111 01001111 110 - Fall 2020

This exercise is about framing. The following character encoding is used in a data link protocol: X: 01000111 Y: 11110111 FLAG: 01111110 ESC:11100111 Show the bit sequence transmitted (in binary) for the four-character frame X Y ESC FLAG when "flag bytes with byte stuffing" is used. Pay attention to the order. Fill in the following 8-bit groups. Some groups at the end may have less than 8 bits. If the group is empty, fill it with "-" (ONE minus character).

01111110 01000111 11110111 11100111 11100111 11100111 01111110 01111110

Fill in multiple blanks. This exercise is about framing. The following character encoding is used in a data link protocol: X: 01000111 Y: 11100111 FLAG: 01111110 ESC:11100111 Show the bit sequence transmitted (in binary) for the four-character frame X Y ESC FLAG when "flag bits with bit stuffing" is used. Pay attention to the order. Fill in the following 8-bit groups. Some groups at the end may have less than 8 bits. If the group is empty, fill it with "-" (ONE minus character).

01111110 ;01000111 ;11010011 ;11101001 ;11011111 ;01001111 ;110 ;-

08 06 80 35 08 06

The following frame was "sniffed" off an Ethernet network. Below, we removed the preamble. We use only hexadecimal numbers without using "0x" or "h" symbols. Here is what was collected in network byte order: 76 3E 56 E2 08 00 08 06 80 35 08 06 08 00 32 7F 4C 2D 5C 4B EE DD .... The source MAC address is ___________________.

08 06 80 35 08 06

Consider this network of routers A, B, C, and D that are using Distance Vector Routing. Assume that all routers are turned on at the exactly same time 0. At time 0, the routers know only the cost to reach their immediate neighbors. At time 0 (Round 0), all routers send their distance vector to their immediate neighbors. Each 30 seconds, a new round of exchanges occurs. Fill in the table below with the distance vector that Node A sends its neighbors on Round 0. If the distance is not yet known, fill in with the value 99.

0;1;2;99

Match the TYPE values with the kind of payload. (Some values were not covered in class. Search for them)

0x0800 - IPv4 0x0806 - ARP 0x8035 - RARP 0x8137 - IPX 0x86DD - IPv6

Assume you just received data is stored in network byte order. Below is a snapshot of the data memory storing data. The first column is the address while second one is the data at that address. The integer (short) variable at address 0x1002 is ___________. Address Content 0x1000 0x34 0x1001 0xB4 0x1002 0x20 0x1003 0xAE 0x1004 0x42 0x1005 0x67 0x1006 0x19 0x1007 0x3C 0x1008 0x8C

0x20AE

Assume you just prepared data stored in little endian order. Below is a snapshot of the data memory storing data. The first column is the address while second one is the data at that address. The integer (short) variable at address 0x1006 is ___________. Address Content 0x1000 0x34 0x1001 0xB4 0x1002 0x20 0x1003 0xAE 0x1004 0x42 0x1005 0x67 0x1006 0x19 0x1007 0x3C 0x1008 0x8C

0x3C19

Assume you just prepared data stored in little endian order. Below is a snapshot of the data memory storing data. The first column is the address while second one is the data at that address. The integer (int) variable at address 0x1004 is ___________. Address Content 0x1000 0x34 0x1001 0xB4 0x1002 0x20 0x1003 0xAE 0x1004 0x42 0x1005 0x67 0x1006 0x19 0x1007 0x3C 0x1008 0x8C

0x3C196742

Assume you just received data is stored in network byte order. Below is a snapshot of the data memory storing data. The first column is the address while second one is the data at that address. The integer (int) variable at address 0x1004 is ___________. Address Content 0x1000 0x34 0x1001 0xB4 0x1002 0x20 0x1003 0xAE 0x1004 0x42 0x1005 0x67 0x1006 0x19 0x1007 0x3C 0x1008 0x8C

0x4267193C

The IP address of some URL at Auburn University is (in binary. Nibbles are separated just to help readability) 1000 0011 1100 1100 0110 1110 1001 1110 This IP address is the same as __________________. 131.204.108.156 in dotted decimal notation None of these answers 0x83CC6E9E 131.204.110.158 in dotted decimal notation 0x83CC6C9C

0x83CC6E9E 131.204.110.158 in dotted decimal notation

Assume you just prepared data stored in little endian order. Below is a snapshot of the data memory storing data. The first column is the address while second one is the data at that address. The integer (int) variable at address 0x1000 is ___________. Address Content 0x1000 0x34 0x1001 0xB4 0x1002 0x20 0x1003 0xAE 0x1004 0x42 0x1005 0x67 0x1006 0x19 0x1007 0x3C 0x1008 0x8C

0xAE20B434

A channel has a capacity of 25 Mbps. Using static allocation, this channel is equally divided between twenty five stations. When using its channel, each station will send with bit rate _________ Mbps.

Consider a system using a frame size equal to 1500 bytes. The bit rate is 12 Mbps. If we use the unit Tr as unit, then 0.001 s = _______________ T_r

Numerical answer. A 125-byte frame is sent at a bitrate of 1 Mbps over a copper cable 1000 kms long. Recall that a copper cable has a propagation speed about 2/3 the speed of light. The transmission time is equal to _________ ms.

The objective is to find the number of ARP requests that will appear on Segment 2 as a result of the actions of ONE user. Read carefully the scenario below. Consider this network: segment.png The IP and MAC addresses are on this table: Host Names A B DNS IP Addresses 128.194.45.110 128.194.45.93 128.194.45.254 MAC Addresses EA EB ED We assume that 1) all hosts on this network are running correctly and that Telnet accepts connections on each host. 2) Initially, the ARP cache of the DNS host is empty while the ARP caches for the rest are as follows Host A 128.194.45.93 EB 128.194.45.254 ED Host B 128.194.45.110 EA 3) The user types on Host B the command "Telnet 128.194.45.254".

The objective is to find the number of ARP requests that will appear on Segment 2 as a result of the actions of ONE user. Read carefully the scenario below. Consider this network: segment.png The IP and MAC addresses are on this table: Host Names A B DNS IP Addresses 128.194.45.110 128.194.45.93 128.194.45.254 MAC Addresses EA EB ED We assume that 1) all hosts on this network are running correctly and that Telnet accepts connections on each host. 2) Initially, the ARP caches of the Host B and DNS host are empty while the ARP cache for Host A is Host A 128.194.45.93 EB 3) The user types on Host A the command "Telnet 128.194.45.93".

Using DNS, each zone (.e., edu, cisco.com, cs.washington.edu, tamu.edu, cs.tamu.edu, .....) must have at least ________ name server(s).

We established that for Slotted Aloha the throughput If S= 0.37 maximum throughout, then G =

What is the value of the parity bit for this word if we are using even parity? Word = 1000 1010

Consider this network of routers A, B, C, and D that are using Distance Vector Routing. Assume that all routers are turned on at the exactly same time 0. At time 0, the routers know only the cost to reach their immediate neighbors. At time 0 (Round 0), all routers send their distance vector to their immediate neighbors. Each 30 seconds, a new round of exchanges occurs (Round 1, 2,...). Fill in the table below with the distance vector that Node B sends its neighbors on Round 1. If the distance is not yet known, fill in with the value 99.

1 0 3 1

Match these wired transmission media from the one supporting the highest bandwidths to the lowest. Assign 1 to the one that supports the highest bandwidths and 99 to the expressions that are not wired media. Optical fiber Coaxial cable Twisted pairs Satellite links Terrestrial microwave

1 2 3 99 99 DELETE

A UDP port number has ______________ bits.

Let us use the following notation: - P s is the packet size (number of bits in P) - b e r be the bit error rate. - p e r is the packet error rate A message M is divided and sent using k packets P i. Let m e r be the message error rate. The probability that the message M is corrupted is equal to _______________.

1 - (1 - per)^k mer

Let us use the following notation: - P s is the packet size (number of bits in P) - b e r be the bit error rate. - p e r is the packet error rate The probability that a bit does not get corrupted is _________.

1 - ber

Let us use the following notation: - P s is the packet size (number of bits in P) - b e r be the bit error rate. - p e r is the packet error rate Check all correct equalities

1 - per = (1 - ber)^Ps per = 1 - (1 - ber)^Ps

A 1 kilobits/s (Kbps) bit rate is _____________ bits per second.

1,000

A 1 megabits/s bit (Mbps) rate is _____________ bits per second.

1,000,000

A 1 gigabits/s (Gbps) bit rate is _____________ bits per second.

1,000,000,000

Let us use the following notation: - P s is the packet size (number of bits in P) - b e r be the bit error rate. - p e r is the packet error rate The probability that a packet does not get corrupted is _________. None of these answers. (1−ber)^PS per ber 1−per

1-per (1 more, NOT ber)

The network ID of IP Address 1.20.140.153 is _________.

1.0.0.0

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". Check the values of N that would make the system unstable (i.e, the system would be overwhelmed to the point that queues on all stations will most likely keep growing). 0.5 0.25 1.01 2 None of these answers .75

1.01 2

The network ID of IP Address 1.20.140.153/17 is _________. 1.20.128.0 None of these answers 1.20.64.0 1.0.0.0 1.20.0.0

1.20.128.0

A 1250-bits frame is sent at a bitrate of 1 Mbps over a copper cable 1000 kms long. Then the transmission time is _________ ms. Propagation speed on copper is about 2/3 the speed of light. The speed of light is about 300,000 km/s.

1.25

a 1250-bits frame is sent at a bitrate of 1 Mbps over a copper cable 1000 kms long. Then the transmission time is _________ ms.

1.25

A sender and a receiver are using a 250 km copper cable to communicate. The propagation speed is about 2/3 the speed of light. They use stop and wait protocol. The frame size is 1250 bytes. The bit rate is 100 Kbps. The propagation time is ______ ms. The transmission time is _____ ms. The throughput is ______ bps. The efficiency is _____ .

1.25 100.00 97560.97 0.97

Suppose a DNS client must resolve the host name toto.nl. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. root Nnl Nvu Local name server

1.25/5 99 99 2 1

Check the information that a DHCP Server provides. None of these answers IP address of gateway router Subnet mask Name of the DNS Server IP address IP address of DNS server

1/4: IP Address of DNS Server NOT None of these answers

A 1250-bits frame is sent at a bitrate of 10 Kbps over a copper cable 2000 kms long. Then the propagation time is _________ ms. Propagation speed on copper is about 2/3 the speed of light. The speed of light is about 300,000 km/s.

This question explores sharing a channel with capacity of 100 Mbps using a static or a dynamic allocation. The static allocation creates channels with equal capacity of 10 Mbps. We assume: -The interarrival time of the packets generated by the stations is exponentially distributed (i.e., arrivals form a Poisson process) The size of the packets is exponentially distributed (i.e., the transmission time of a packet is exponentially distributed). With dynamic allocation, the average packet delivery is ____________ times smaller than with static allocation.

Let S/N be the ratio of the signal S over the noise N. The S/N ratio (in decibel) is 20 decibels (dB). Then S/N = ________.

100

1000

Let S/N be the ratio of the signal S over the noise N. The S/N ratio (in decibel) is 30 decibels (dB). Then S/N = ________.

1000

Let S/N be the ratio of the signal S over the noise N. The S/N ratio (in decibel) is 40 decibels (dB). Then S/N = ________.

10000

A 5x5 word that includes crossed even parity bits is received: 1010 0010 1111 1010 1100 0011 0 The initial (sent) 5x5 word must have been _____________________

1010 0000 1111 1010 1100 0011 0

Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.65.171. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.67 read the routing table ask ARP for a MAC address corresponding to IP Address 134.89.200.54 ask ARP for a MAC address corresponding to IP Address 134.89.200.67 check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.254 ask ARP for a MAC address corresponding to IP Address 134.89.200.1

11.43/20 3 2 0 0 1 0 4

The sender wants to send the message 1100001 using odd parity. It will send the frame___________.

11000010

Using even parity, the receiver receives the frames listed below. Check the frames that were certainly corrupted (including the parity bit)

11000010 10000000 11011010

The sender sent this message 110X101 using even parity. The 'X' is a bit that is unknown. The message is received correctly, i.e., it was not corrupted during transmission. The receiver receives the message___________.

1100101

The sender wants to send the message 1101001 using even parity. It will send the frame___________.

11010010

The sender wants to send the message 1101001 using odd parity. It will send the frame___________.

11010011

TCP port number has __ bits

The sender sent this message 110X101 using odd parity. The 'X' is a bit that is unknown. The message is received correctly, i.e., it was not corrupted during transmission. The receiver receives the message___________.

1101101

The sender sent this message 11X1101 using odd parity. The 'X' is a bit that is unknown. The message is received correctly, i.e., it was not corrupted during transmission. The receiver receives the message___________. 1101101 1111101 None of these answers 1101100 1111100

1101101

The sender wants to send the message 1101101 using even parity. It will send the frame___________.

11011011

Using odd parity, the receiver receives the frames listed below. Check the frames that were certainly corrupted (including the parity bit)

11111111 00000000 11000011

A 1250-bits frame is sent at a bitrate of 100 Kbps over a copper cable 1000 kms long. Then the transmission time is _________ ms.

12.5

Check all that apply. A 1250-bits frame is sent at a bitrate of 100 Kbps over a copper cable 1000 kms long. Then the transmission time is _________ ms. Propagation speed on copper is about 2/3 the speed of light. The speed of light is about 300,000 km/s.

12.5

A sender and a receiver are using a 2500 km copper cable to communicate. The propagation speed is about 2/3 the speed of light. They use stop and wait protocol. The frame size is 1500 bytes. The bit rate is 10 Mbps. The propagation time is _____ ms. The transmission time is _____ ms. The throughput is ______ bps. The efficiency is _____ .

12.50 1.20 458015.26 0.04

A 1250-bits frame is sent at a bitrate of 10 Kbps over a copper cable 1000 kms long. Then the transmission time is _________ ms. Propagation speed on copper is about 2/3 the speed of light. The speed of light is about 300,000 km/s.

125

The network ID of IP Address 126.200.40.13 is _________.

126.0.0.0

The network ID of IP Address 126.204.40.13/13 is _________. 126.192.0.0 126.128.0.0 126.200.0.0 126.204.0.0 None of these answers

126.200.0.0

Suppose you want to send some packet to the host from which you are sending. You could use this (these) addresse(s).

127.0.0.1 0.0.0.0

An IPv6 address has __bits

128

The network ID of IP Address 128.200.40.13 is _________.

128.200.0.0

The network ID of IP Address 128.200.104.13/19 is _________.

128.200.96.0

A host H has IP address 131.204.14.65. Suppose you want to send some packet to all hosts on the same network as H . You could use this (these) addresse(s). 131.255.255.255 131.204.14.255 None of these answers 255.255.14.65 131.204.255.255

131.204.255.255

The subnet mask of network N is 255.255.255.240. This network N can assign unique addresses to up to _______________ hosts. 14 6 8 16 None of these answers

This question is about how the Internet Protocol (IP) handles a packet P and decides where to deliver it. Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.64.159. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.254 read the routing table ask ARP for the MAC address corresponding to IP Address 134.89.200.67 ask ARP for the MAC address corresponding to IP Address 134.89.200.254 check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.67 ask ARP for the MAC address corresponding to IP Address 134.89.200.128

14.29 / 20 0 2 0 0 1 0 0

A 1250-bits frame is sent at a bitrate of 10 Kbps over a copper cable 3000 kms long. Then the propagation time is _________ ms. Propagation speed on copper is about 2/3 the speed of light. The speed of light is about 300,000 km/s.

A TCP port number has ______ bits.

A TCP port number has ______________ bits.

A UDP port number has __ bits

The network ID of IP Address 191.20.240.213 is _________.

191.20.0.0

The network ID of IP Address 191.20.240.213/18 is _________.

191.20.192.0

The network ID of IP Address 192.202.100.3 is _________.

192.202.100.0

The network ID of IP Address 192.202.100.243/28 is _________.

192.202.100.240

Consider this network of routers A, B, C, and D that are using Distance Vector Routing. Assume that all routers are turned on at the exactly same time 0. At time 0, the routers know only the cost to reach their immediate neighbors. At time 0 (Round 0), all routers send their distance vector to their immediate neighbors. Each 30 seconds, a new round of exchanges occurs. Fill in the table below with the distance vector that Node B sends its neighbors on Round 0. If the distance is not yet known, fill in with the value 99.

1;0;5;1

A hamming code of distance 6 can detect and correct up to _______ corrupted bits in a received word..

Five senders share a 10 Mbps channel using code division multiplexing. Each sender will have a sending bit rate of about ________ Mbps.

In order to evaluate the Pure Aloha protocol, we defined the probability P_0 as having no collisions. We observed that this probability is equal to the probability of 0 transmitted frame during _____ unit(s) time. Recall we are using the transmission time T_r as unit.

This question explores sharing a channel with capacity of 100 Mbps using a static or a dynamic allocation. The static allocation creates channels with equal capacity of 50 Mbps. We assume: -The interarrival time of the packets generated by the stations is exponentially distributed (i.e., arrivals form a Poisson process) The size of the packets is exponentially distributed (i.e., the transmission time of a packet is exponentially distributed). With dynamic allocation, the average packet delivery is ____________ times smaller than with static allocation.

Consider this network of routers A, B, C, and D that are using Distance Vector Routing. Assume that all routers are turned on at the exactly same time 0. At time 0, the routers know only the cost to reach their immediate neighbors. At time 0 (Round 0), all routers send their distance vector to their immediate neighbors. Each 30 seconds, a new round of exchanges occurs (Round 1, 2,...). Fill in the table below with the distance vector that Node D sends its neighbors on Round 1. If the distance is not yet known, fill in with the value 99.

2 1 3 0

Consider this network of routers A, B, C, and D that are using Distance Vector Routing. Assume that all routers are turned on at the exactly same time 0. At time 0, the routers know only the cost to reach their immediate neighbors. At time 0 (Round 0), all routers send their distance vector to their immediate neighbors. Each 30 seconds, a new round of exchanges occurs (Round 1, 2,...). Fill in the table below with the distance vector that Node C sends its neighbors on Round 1. If the distance is not yet known, fill in with the value 99.

2 3 0 3

Assume that the local name server just started (cache empty). Suppose a DNS client must resolve the host name toto.vu.nl. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. root Nnl Nvu Nwas Local name server

2 3 4 99 1

Assume that the local name server just started (cache empty). Suppose a DNS client must resolve the host name toto.jill.acm.org. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. root Nacm Norg Nwas Local name server

2 4 3 99 1

Select the best answer from each dropdown menu. Use byte counting to frame the words "I", "Love", "THE", and "Constitution". A frame is made of one word that may contain multiple characters (do not count space characters). Complete the framing of the above words: [blank] I [blank] Love [blank] THE [blank] Constitution

2 5 4 None of these answers

Assume that the local name server just started (cache empty). Suppose a DNS client must resolve the host name toto.org. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. root Nacm Norg Local name server

2 99 3 1

Assume that the local name server just started (cache empty). The local name server just resolved the hostname tatiana.cs.washington.edu and right after a DNS client must resolve the host name toto.robot.cs.washington.edu. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. Ncs Nedu root Nwas Local name server

2 99 99 99 1

The length of an IPv4 header is at least ________ bytes.

A channel has a capacity of 25 Mbps. Using dynamic allocation, this channel is shared between twenty five stations. When using the channel, any station will send with bit rate _________ Kbps.

25000

Assume that the local name server just started (cache empty). The local name server just resolved the hostname tatiana.robot.cs.washington.edu and right after a DNS client must resolve the host name toto.cs.washington.edu. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. Ncs Nedu root Nwas Local name server

2 99 99 99 1

Assume that the local name server just started (cache empty). The local name server just resolved the hostname tatiana.robot.cs.washington.edu and right after a DNS client must resolve the host name toto.robot.cs.washington.edu. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. Ncs Nedu root Nwas Local name server

2 99 99 99 1

Suppose that we transmit symbols belonging to this vocabulary {A, B}. The baud rate is 2,000 bauds. The bit rate is.

2 Kbps

2 T p + T r + C t + T a T r + C t + T a + 2 T p T p + T r + C t + T a + T p

This question explores the number of check bits needed by techniques to detect and correct one byte. Sort these techniques based on the number of check bits they would required. The technique that requires the least should be assigned the number 0. If two techniques require the same number of check bits, then assign them the same number. No detection or correction 0 Detect up to one corrupted bit 0 Detect up to one corrupted bit using odd parity 0 Detect up to one corrupted bit using even parity 0 Detect and correct up to one corrupted bit 1 Detect and correct up to two corrupted bit

2.08/12.5 0 0 0 1 2

Numerical answer. Four senders share a 10 Gbps channel using time division multiplexing. Each sender will have a sending bit rate of about ________ Gbps.

2.5

A sender and a receiver are using a 500 km copper cable to communicate. The propagation speed is about 2/3 the speed of light. They use stop and wait protocol. The frame size is 1500 bytes. The bit rate is 1 Mbps. The propagation time is _____ ms. The transmission time is _____ ms. The throughput is _____ bps. The efficiency is _____ .

2.50 12.00 705882.35 0.70

A sender and a receiver are using a 500 km copper cable to communicate. The propagation speed is about 2/3 the speed of light. They use stop and wait protocol. The frame size is 1500 bytes. The bit rate is 100Kbps. The propagation time is _____ ms. The transmission time is _____ ms. The throughput is _____ bps. The efficiency is _____ .

2.50 120.00 96000.00 0.96

This question is about how the Internet Protocol (IP) handles a packet P and decides where to deliver it. Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.65.172. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.54 read the routing table ask ARP for a MAC address corresponding to IP Address 134.89.200.67 ask ARP for a MAC address corresponding to IP Address 134.89.200.254 check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.67

2.67/4 0 2 0 0 1 0

This question is about how the Internet Protocol (IP) handles a packet P and decides where to deliver it. Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.64.170. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.128 read the routing table ask ARP for the MAC address corresponding to IP Address 134.89.200.67 ask ARP for the MAC address corresponding to IP Address 134.89.200.1 check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.67

2.67/4 0 2 3 0 1 4

A 1250-bits frame is sent at a bitrate of 10 Kbps over a copper cable 4000 kms long. Then the propagation time is _________ ms.

A 1250-bits frame is sent at a bitrate of 10 Kbps over a copper cable 4000 kms long. Then the propagation time is _________ ms. Propagation speed on copper is about 2/3 the speed of light. The speed of light is about 300,000 km/s.

Let S/N be the ratio of the signal S over the noise N. If S/N = 100 then the SNR is ______ decibels (dB).

This question explores sharing a channel with capacity of 100 Mbps using a static or a dynamic allocation. The static allocation creates channels with equal capacity of 5 Mbps. With dynamic allocation, the average packet delivery is ____________ times smaller than with static allocation.

Five senders share a 1 Mbps channel using frequency division multiplexing. Each sender will have a sending bit rate of about ________ Kbps.

200

The network ID of IP Address 200.20.14.53 is _________.

200.20.14.0

The network ID of IP Address 200.20.14.53/27 is _________.

200.20.14.32

A host H has IP address 200.204.14.65. Suppose you want to send some packet to all hosts on the same network as H . You could use this (these) addresses.

200.204.14.255

Five senders share a 10 Mbps channel using code division multiplexing. Each sender will have a sending bit rate of about ________ Kbps.

2000

In the TCP/IP model, an FTP server uses in general this (these) port number(s) at the transport layer.

21, 20

The network ID of IP Address 212.202.100.3 is _________.

212.202.100.0

The network ID of IP Address 212.202.100.63/28 is _________.

212.202.100.48

In the TCP/IP model, an SSH server uses in general this (these) port number(s) at the transport layer.

The network ID of IP Address 223.202.100.3 is _________.

223.202.100.0

The network ID of IP Address 223.202.100.13/30 is _________.

223.202.100.12

In the TCP/IP model, a Telnet server uses in general this (these) port number(s) at the transport layer.

A 1250-bits frame is sent at a bitrate of 10 kbps over a copper cable 5000 kms long. Then the propogation time is _________ ms.

SMTP binds to Port Number _______________. POP3 binds to Port Number _______________. IMAP binds to Port Number _______________.

25 110 143

A channel has a capacity of 25 Mbps. Using dynamic allocation, this channel is shared between twenty five stations. When using the channel, any station will send with bit rate _________ Kbps.

25,000

A sender and a receiver are using a 5,000 km copper cable to communicate. The propagation speed is about 2/3 the speed of light. They use stop and wait protocol. The frame size is 1250 bytes. The bit rate is 1 Mbps. The propagation time is _____ ms. The transmission time is _____ ms. The throughput is _____ bps. The efficiency is _____ .

25.00 10.00 166666.66 0.16

Numerical answer. Four senders share a 1 Gbps channel using time division multiplexing. Each sender will have a sending bit rate of about ________ Mbps.

250

A channel has a capacity of 25 Mbps. Using dynamic allocation, this channel is shared between fifty stations. When using the channel, any station will send with bit rate _________ Kbps.

25000

A class C network can assign unique addresses to up to _______________ hosts.

254

Assume that the local name server just started (cache empty). The local name server just resolved the hostname tatiana.washington.edu and right after a DNS client must resolve the host name toto.robot.cs.washington.edu. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. Ncs Nedu root Nwas Local name server

3 99 99 2 1

3.13 / 6.25 DNS B A

Let S/N be the ratio of the signal S over the noise N. If S/N = 1,000 then the SNR is ______ decibels (dB).

An IPv4 address has ________ bits

IPv4 address has __ bits

The subnet mask of network N is 255.255.128.0. This network N can assign unique addresses to up to _______________ hosts.

32766

Consider a 4-KHz noisy channel with a 30 db SNR. The sender is using the vocabulary set S to communicate. S = {apple, banana}. The maximal bit rate is _________ bps.

39869 Explanation: bit rate = B*log2(1 + S/N) SNR = 30 = 10log10(S/N) S/N = 1000 4000*log2(1001) = 39869

Consider these two words: W1 = 1001 1001 W2 = 0101 1010 The Hamming distance between W1 and W2 is _____.

In the IPv4 header, the size of the header length (IHL) field on an IPv4 header is ________ bits.

The email architecture has ________ components.

The number of layers that the TCP/IP Reference Model specifies explicitly is ________ .

The size of the version field on an IPv4 header is ________ bits.

This question is about how the Internet Protocol (IP) handles a packet P and decides where to deliver it. Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 134.89.200.24. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.24 check if Packet P is for Device D read the routing table ask ARP for a MAC address corresponding to IP Address 134.89.200.24 ask ARP for a MAC address corresponding to IP Address 134.89.200.128 hand Packet P to the appropriate protocol at the transport layer. check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.18

4 1 0 3 0 0 2 0

This question is about how the Internet Protocol (IP) handles a packet P and decides where to deliver it. Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.64.159. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.254 read the routing table ask ARP for the MAC address corresponding to IP Address 134.89.200.67 ask ARP for the MAC address corresponding to IP Address 134.89.200.254 check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.67 ask ARP for the MAC address corresponding to IP Address 134.89.200.128

4 2 0 3 1 0 0

This question is about how the Internet Protocol (IP) handles a packet P and decides where to deliver it. Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.65.171. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.67 read the routing table ask ARP for a MAC address corresponding to IP Address 134.89.200.54 ask ARP for a MAC address corresponding to IP Address 134.89.200.67 check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.254 ask ARP for a MAC address corresponding to IP Address 134.89.200.1

4 2 0 3 1 0 0

Assume that the local name server just started (cache empty). The local name server just resolved the hostname tatiana.edu and right after a DNS client must resolve the host name toto.robot.cs.washington.edu. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. Ncs Nedu root Nwas Local name server

4 2 99 3 1

Suppose that we transmit symbols belonging to this vocabulary {A, B, C, D}. The baud rate is 2,000 bauds. The bit rate is. 4 Kbps 1 Kbps 2 Kbps 8 Kbps None of these choices

4 Kbps

The OSI reference model has _____ end-to-end layers and _____ point-to-point layers.

4, 3

Consider this network: router.png Hosts A, B, C, and DNS have MAC addresses Ea, Eb, Ec, and Ed, respectively. The bridge cache is as follows: MAC Addresses Ports Ed P2 Ea P1 Consider this frame that was just sent: frameFFEb.png Besides its sender, this frame is seen by Host(s) _____________ . None of these answers A C DNS Router Interface on Segment 1 B Router Interface on Segment 3

4.17 / 6.25 A DNS 2.08/6.25 DNS B A

Let S/N be the ratio of the signal S over the noise N. If S/N = 10,000, then the SNR is ______ decibels (dB).

The network ID of IP Address 45.20.14.53 is _________.

45.0.0.0

The network ID of IP Address 45.20.14.53/12 is _________.

45.16.0.0

This question explores the time to send and acknowledge a frame when using retransmission on a noisy (error-prone) channel. We assume that: 1) it takes Time C to send a frame (C=T(m+n) as defined on the slides)2) there is a penalty P when a (re)transmission fails.3) the packet error rate is per. It takes time ________________ to send a frame and get a positive acknowledgement when only the fourth transmission is successful. ( 4. C + 3. P ) . p e r 3 . ( 1 − p e r ) 3. C + 2. P 4. B + 3. A 4. C + 3. P None of these answers.

4C +3P

A 1250-bits frame is sent at a bitrate of 10 Kbps over a copper cable 1000 kms long. Then the propagation time is _________ ms. Propagation speed on copper is about 2/3 the speed of light. The speed of light is about 300,000 km/s.

A hamming code of distance 6 can detect up to _______ corrupted bits in a received word..

Check all that apply. A 1250-bits frame is sent at a bitrate of 10 Kbps over a copper cable 1000 kms long. Then the propagation time is _________ ms. Propagation speed on copper is about 2/3 the speed of light. The speed of light is about 300,000 km/s.

The Hamming distance for Code C is such that 1) the largest distance between any two codewords is 7 2) the smallest distance between any two codewords is 5. The Hamming distance for Code C is ________.

This question is about how the Internet Protocol (IP) handles a packet P and decides where to deliver it. Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.65.14. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.1 check if Packet P is for Device D read the routing table ask ARP for a MAC address corresponding to IP Address 134.89.200.1 ask ARP for a MAC address corresponding to IP Address 131.89.200.254 hand Packet P to the appropriate protocol at the transport layer. check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.254

5 1 3 4 0 0 2 0

Suppose a DNS client must resolve the host name toto.cs.washington.edu. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. Ncs Nedu root Nacm Nwas Local Name Server

5 3 2 99 4 1

Suppose a DNS client must resolve the host name toto.robot.cs.washington.edu. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. Ncs Nedu root Nvu Nwas Local name server

5 3 2 99 4 1

5 ms .005 s

A sender and a receiver are using a 1,000 km copper cable to communicate. The propagation speed is about 2/3 the speed of light. They use stop and wait protocol. The frame size is 125 bytes. The bit rate is 1 Mbps. The propagation time is _____ ms. The transmission time is _____ ms. The throughput is _____ bps. The efficiency is _____ .

5.00 1.00 90909.09 0.09

A 1250-bits frame is sent at a bitrate of 10 Kbps over a copper cable 10,000 kms long. Then the propagation time is _________ ms. Propagation speed on copper is about 2/3 the speed of light. The speed of light is about 300,000 km/s.

A channel has a capacity of 50 Mbps. Using dynamic allocation, this channel is shared between fifty stations. When using the channel, any station will send with bit rate _________ Mbps.

A channel has a capacity of 50 Mbps. Using dynamic allocation, this channel is shared between twenty five stations. When using the channel, any station will send with bit rate _________ Mbps.

A channel has a capacity of 25 Mbps. Using static allocation, this channel is equally divided between fifty stations. When using its channel, each station will send with bit rate _________ Kbps.

500

Consider this code snapshot: String str = new String("CD456"); byte[] a = str.getBytes(); The content of a[2] is ___________.

A DNS server binds to Port # _______.

In the TCP/IP model, DNS uses this (these) port number(s) at the transport layer.

In the TCP/IP model, a DNS server uses in general this (these) port number(s) at the transport layer.

Consider a 4-KHz noisy channel with a 40 db SNR. The sender is using the vocabulary set S to communicate. S = {apple, banana}. The maximal bit rate is _________ bps.

53,151.42

Match each socket function call to the sequence it will appear on a Java TCP server. The first/earliest call is assigned the number 1. The earlier is a function call, the smaller is its assigned number. The statements must be compatible (i.e., use appropriate variables from earlier valid statements). b = s.getInputStream(); s = new ServerSocket(..); a = cs.getInputSteam(); s.close() cs = s.accept(); a.read(...)

77 1 3 99 2 4

Match each socket function call to the sequence it will appear on a Java TCP server. The first/earliest call is assigned the number 1. The earlier is a function call, the smaller is its assigned number. The statements must be compatible (i.e., use appropriate variables from earlier valid statements). b = s.getInputStream(); s = new ServerSocket(..); a = cs.getOutputSteam(); s.close() cs = s.accept(); a.write(...)

77 1 3 99 2 4

Match each socket function call to the sequence it will appear on a Java TCP server. The first/earliest call is assigned the number 1. The earlier is a function call, the smaller is its assigned number. The statements must be compatible (i.e., use appropriate variables from earlier valid statements). b = s.getInputStream(); s = new ServerSocket(..); a = cs.getOutputStream(); s.close() cs = s.accept(); a.read(...)

77 1 3 99 2 4

Match each socket function call to the sequence it will appear on a Java TCP client. The first/earliest call is assigned the number 1. The earlier is a function call, the smaller is its assigned number. The statements must be compatible (i.e., use appropriate variables from earlier valid statements). b = cs.getOutputStream(); s = new ServerSocket(..); a = s.getInputStream(); a.read(...) cs = s.accept(); b.read(...) s = new Socket(..);

77 77 2 3 77 77 1

A network is made of a ring of 16 nodes using bidirectional point-to-point links. These nodes use distance vector routing. Suppose these nodes turn on at the same time. How many rounds of communications are needed for all the nodes to update their routing tables with ALL nodes in the network.

8 at most

Consider a 4-KHz noiseless channel. The sender is using the vocabulary set S to communicate. S = {apple, banana}. The maximal bit rate is _________ bps.

8,000

Check all true statements assuming that n < m.

8.33/12.5 Detecting up to n corrupted bits requires fewer check bits than for detecting up to m corrupted bits Detecting and correcting up to n corrupted bits requires fewer check bits than for detecting and correcting up to m corrupted bits

In the TCP/IP model, an HTTP server uses in general this (these) port number(s) at the transport layer.

Match these popular protocols (services) to their port numbers. HTTP SMTP Telnet SSH DNS

80(TCP) 25(TCP) 23(TCP) 22(TCP) 53(UDP)

Consider a 4-KHz noiseless channel. The sender is using the vocabulary set S to communicate. S = {apple, banana}. The maximal bit rate is _________ bps.

8000

Numerical answer. Consider a 4-KHz noiseless channel. The sender is using the vocabulary set S to communicate. S = {apple, banana, pear, mango}. The maximal baud (symbol) rate is _________ bauds.

8000

A network is made of a chain of 10 nodes. These nodes use distance vector routing. Suppose these nodes turn on at the same time. How many rounds of communications are needed for all the nodes to update their routing tables with ALL nodes in the network?

Match these protocols in the TCP/IP reference model to some protocol they use in the layer below theirs. IP HTTP UDP IMAP DNS

9/11.25 IP - IEEE 802.11 HTTP - UDP UDP - IP IMAP - TCP DNS - UDP

Consider this network of routers A, B, C, and D that are using Distance Vector Routing. Assume that all routers are turned on at the exactly same time 0. At time 0, the routers know only the cost to reach their immediate neighbors. At time 0 (Round 0), all routers send their distance vector to their immediate neighbors. Each 30 seconds, a new round of exchanges occurs. Fill in the table below with the distance vector that Node D sends its neighbors on Round 0. If the distance is not yet known, fill in with the value 99.

99 1 3 0

Assume that the local name server just started (cache empty). Suppose a DNS client must resolve the host name toto.fluit.cs.vu.nl. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. Ncs root Nnl Nvu Local name server

99 2 3 4 1

Suppose a DNS client must resolve the host name toto.cs.vu.nl. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. Ncs root Nnl Nvu local name server

99 2 3 4 1

Assume that the local name server just started (cache empty). The local name server just resolved the hostname tatiana.robot.cs.washington.edu and right after a DNS client must resolve the host name toto.edu. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. Ncs Nedu root Nwas Local name server

99 2 99 99 1

Assume that the local name server just started (cache empty). Suppose a DNS client must resolve the host name toto.eng.washington.edu. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. Ncs Nedu root Nwas Local name server

99 3 2 4 1

Suppose a DNS client must resolve the host name toto.washington.edu. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. Ncs Nedu root Nwas Local name server

99 3 2 4 1

Suppose a DNS client must resolve the host name toto.edu. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. Ncs Nedu root Nwas local name server

99 3 2 99 1

Assume that the local name server just started (cache empty). The local name server just resolved the hostname tatiana.filts.cs.vu.nl and right after a DNS client must resolve the host name toto.cs.vu.nl. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. Ncs root Nnl Nvu Local name server

99 99 99 2 1

Assume that the local name server just started (cache empty). The local name server just resolved the hostname tatiana.filts.cs.vu.nl and right after a DNS client must resolve the host name toto.fluit.cs.vu.nl. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. Ncs root Nnl Nvu Local name server

99 99 99 2 1

Assume that the local name server just started (cache empty). The local name server just resolved the hostname tatiana.fluit.cs.vu.nl and right after a DNS client must resolve the host name toto.fluit.cs.vu.nl. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. Ncs root Nnl Nvu Local name server

99 99 99 2 1

Assume that the local name server just started (cache empty). The local name server just resolved the hostname tatiana.robot.cs.washington.edu and right after a DNS client must resolve the host name toto.washington.edu. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. Ncs Nedu root Nwas Local name server

99 99 99 2 1

Assume that the local name server just started (cache empty). The local name server just resolved the hostname tatiana.vu.nl and right after a DNS client must resolve the host name toto.cs.vu.nl. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. Ncs root Nnl Nvu Local name server

99 99 99 2 1

Consider this network of routers A, B, C, and D that are using Distance Vector Routing. Assume that all routers are turned on at the exactly same time 0. At time 0, the routers know only the cost to reach their immediate neighbors. At time 0 (Round 0), all routers send their distance vector to their immediate neighbors. Each 30 seconds, a new round of exchanges occurs. Fill in the table below with the distance vector that Node C sends its neighbors on Round 0. If the distance is not yet known, fill in with the value 99.

A = 2 B = 5 C = 0 D = 3

The network ID of IP Address 172.20.14.53 is _________.

None of these answers

A personal area network (PAN) is a network covering typically _____

A small car

Consider this network: Hosts A, B, and DNS have MAC addresses Ea, Eb, and Ed, respectively. The bridge cache is as follows: MAC addresses Ports Ed P2 Eb P1 Consider this frame that was just sent (Ignore the number 2 in the "Segment" Column): frameEbEd.png Besides its sender, this frame is seen by Host(s) _____________ .

A, B

Consider this network: Hosts A, B, and DNS have MAC addresses Ea, Eb, and Ed, respectively. The bridge cache is empty. The following frame appears on Segment 4 (Ignore the number 2 in the "Segment" Column): frameFFEb.png Besides its sender, this frame is seen by Host(s) _____________ .

A, DNS

Consider this network: bridge.png Hosts A, B, and DNS have MAC addresses Ea, Eb, and Ed, respectively. The bridge cache is as follows: MAC addresses Ports Ed P2 Eb P1 Consider this frame that was just sent: frameFFEb.png Besides its sender, this frame is seen by Host(s) _____________ . C A None of these answers B DNS

A, DNS

Consider this network: bridge.png Hosts A, B, and DNS have MAC addresses Ea, Eb, and Ed, respectively. The bridge cache is empty. Consider this frame that was just sent: frameEaEb.png Besides its sender, this frame is seen by Host(s) _____________ . None of these answers A B C DNS

A, DNS

Consider this network: segment.png Hosts A, B, and DNS have MAC addresses Ea, Eb, and Ed, respectively. The following frame appears on Segment 2: frameFFEb.png Besides its sender, this frame is picked by Host(s) _____________ for further processing by the link layer. B C A DNS None of these answers

A, DNS

Consider this network: router.png Hosts A, B, C, and DNS have MAC addresses Ea, Eb, Ec, and Ed, respectively. The bridge cache is initially empty: Consider this frame that was just sent: frameEaEb.png Besides its sender, this frame is seen by Host(s) _____________ . None of these answers DNS C B Router Interface on Segment 1 Router Interface on Segment 3 A

A, DNS, Router Interface on Segment 1

Apart the difference in the layers where they perform, DNS is a service most similar to the _________ service.

ARP

A class A network can assign unique addresses to up to _______________ hosts. about 16 millions 224 None of these answers 216-2 220

About 16 millions

The physical layer offers in general these services/functions.

None of these answers

ASK stands for -------- -------- --------

Amplitude Shift Keying

The following frame was "sniffed" off an Ethernet network. Below, we removed the preamble. We use only hexadecimal numbers without using "0x" or "h" symbols. Here is what was collected in network byte order: 08 06 80 35 08 06 76 3E 56 E2 08 00 08 06 32 7F 4C 2D 5C 4B EE DD .... This frame certainly carries as payload _______________.

An ARP packet

An IPv4 packet

Check all that apply to dynamic allocation of a broadcast channel with capacity C assuming there are n stations with n ≥ 2. None of these answers. At any point of time, the sum of the capacities used by all stations is less or equal to C. Each station can momentarily claim and use the full capacity CC of the channel. Each station gets only a fraction ( < 1.0 )( < 1.0 ) of the full capacity of the broadcast channel. The capacity C is divided between at least two channels .

At any point of time, the sum of the capacities used by all stations is less or equal to C. Each station can momentarily claim and use the full capacity CC of the channel.

Consider this network: segment.png Hosts A, B, and DNS have MAC addresses Ea, Eb, and Ed, respectively. The following frame appears on Segment 2: frameEbEd.png This frame is picked by Host(s) _____________ for further processing by the link layer.

Consider this network: segment.png Hosts A, B, and DNS have MAC addresses Ea, Eb, and Ed, respectively. The following frame appears on Segment 2: frameFFEb.png This frame was sent by Host(s) _________________________.

The class of IP Address 128.200.40.13 is _________.

The class of IP Address 164.200.40.13 is _________.

The class of IP Address 172.202.100.3 is _________.

The class of IP Address 191.20.240.213 is _________.

Consider this network: segment.png Hosts A, B, and DNS have MAC addresses Ea, Eb, and Ed, respectively. The following frame appears on Segment 2: frameEbEd.png Besides its sender, this frame is seen by Host(s) _____________. B None of these answers A C DNS

B A

Based on Nyquist, any medium/channel (even perfect) has a maximal capacity to carry bits. Any signal running through a low-pass filter of bandwidth B will have a maximal data rate max. If the signal consists of V discrete levels. Nyquist theorem states: max = 2 _____ log 2 ( _____ ) bits/s

B V

This (These) protocol(s) use(s) distance vector routing or one of its improved variants.

BGP RIP

IP (Internet Protocol) may get service directly from these protocols.

Bluetooth Ethernet Wifi

IP (Internet Protocol) may get service directly from these protocols.

Bluetooth Wifi Ethernet

Check all concepts/tools/protocols that may be used to modify (update) routing tables. Border Gateway Protocol IEEE 802.3 Open Shortest Path First Medium Access Control None of these answers

Border Gateway Protocol Open Shortest Path First

This (These) protocol(s) is (are) exterior gateway protocol(s) used to update routing tables.

Border Gateway Protocol (BGP)

This (These) protocol(s) is (are) routing protocol(s) (modifying routing tables) that could be used on the Internet backbone.

Border Gateway Protocol (BGP)

Select the best definition for framing.

Breaking a stream of bits into data units

Wireless local area networks (LANs) often use ___________________ channel(s).

Broadcast

With two or more users emitting/transmitting/talking, the MAC is needed for the following topologies.

Broadcast Half-duplex

With two or more users emitting/transmitting/talking, the MAC is needed for the following topologies.

Broadcast & half duplex

FSK stands for _____ _____ _____

Frequency Shift Keying

The class of IP Address 192.202.100.3 is _________.

The class of IP Address 200.20.14.53 is _________.

The class of IP Address 212.202.100.3 is _________.

The class of IP Address 223.202.100.3 is _________.

Check all metrics that are similar to efficiency as defined in this course. CPU busy time number of processes completed per second by a CPU number of copied pages per minute by a photocopier number of printed pages per minute by a printer CPU utilization percentage/fraction None of these answers

CPU utilization percentage/fraction

On an Ethernet frame, the ________ field indicates whether the frame is corrupted.

CRC

These MAC protocols/schemes use Carrier Sense Multiple Access

CSMA CSMA/CD

These multiple access protocols/schemes must sense the medium before transmitting.

CSMA CSMA/CD

These multiple access protocols/schemes must listen to the medium while transmitting.

CSMA/CD

These protocols are multiple access protocols/schemes.

Carrier Sense Multiple Access (CSMA) Slotted Aloha Pure Aloha

A metropolitan area network (MAN) is a network covering typically _____

City

_________ is the design issue that consists of avoiding that a sender overwhelms the receiver and any intermediary nodes.

Congestion control

Check all techniques we studied earlier that can in general be used for detecting up to one corrupted bit. adding a parity bit Hamming codes with distance 2 Cyclic Redundancy Check crossed parities checksum None of these answers.

Cyclic Redundancy Check adding a parity bit Hamming codes with distance 2 crossed parities checksum

Most applications on any host on the Internet will use the service offered by this protocol.

DNS

DNS A Router Interface on Segment 1

Check all applications that use UDP. IMAP Telnet ssh DNS Trivial FTP

DNS Trivial FTP

Check the protocol(s) that belong(s) to the application layer

DNS SMTP HTTP SSH

Most hosts on the Internet will have these protocols active on them.

DNS client DHCP client TCP DELETE

In the TCP/IP model, TCP uses this (these) protocol(s) at the network (Internet) layer.

IPv4 IPv6

In OSI reference model the MAC is a sublayer of what layer

Data Link

In the OSI Reference Model (computer networks), the MAC is a sublayer of the ________________ layer

Data Link

In the OSI reference model, the physical layer offers service directly to the [name1] layer.

Data Link

The HDLC protocol may be provided by this (these) layer(s) in the OSI Reference model.

Data Link

The PPP protocol may be provided by this (these) layer(s) in the OSI Reference model.

Data Link

In the OSI reference model, this layer is an intruder (i.e., it does not belong within this list of options).

Data Link ------------------------------------------ None of the above Application Presentation Data Link Transport

In the TCP/IP Reference Model, a bridge uses this (these) layer(s) when carrying a conversation.

Data Link / Link

In the TCP/IP Reference Model, an L2 switch uses this (these) layer(s) when carrying a conversation.

Data Link / Link

In the TCP/IP Reference Model, these layers are mostly implemented by hardware on most hosts (clients or servers).

Data Link / Link

In the TCP/IP Reference Model, your Ethernet interface uses this (these) layer(s) when you are browsing the Internet.

Data Link / Link

In the TCP/IP Reference Model, an L3 switch uses this (these) layer(s) when carrying a conversation.

Data Link / Link Internet / Network

In the OSI Reference Model, these layers are mostly implemented by hardware on most hosts (clients or servers).

Data Link / Link Physical

In the OSI Reference Model, your Ethernet interface uses this (these) layer(s) when you are browsing the Internet.

Data Link / Link Physical

In the TCP/IP Reference Model, your wireless network interface uses this (these) layer(s) when you are browsing the Internet.

Data Link/Link

In the OSI Reference Model, your Bluetooth interface uses this (these) layer(s) when you are browsing the Internet.

Data Link/Link Physical

Consider the method p.recieve(s) where p = new DatagramSocket(); The type of the parameter s is _______

DatagramPacket

Consider the method p.send(s) where p = new DatagramSocket(); the type of the parameter s is __________

DatagramPacket

Select the best answer. Consider this incomplete code snapshot: int a, e; short b, f; byte g; DataOutputStream c; DatagramSocket d; InputStream w; ByteArrayOutStream x = new ByteArrayOutputStream(); c = new DataOutputStream(x); DataInputStream s = new DataInputStream(w); If I write a statement d.send(m), m is most likely of type

DatagramPacket

Any UDP client socket program in Java must use this function call to establish a socket

DatagramSocket

Any UDP server socket program in Java must use this function call to establish a socket

DatagramSocket

The method DatagramSocket() returns a result of type

DatagramSocket

Match each protocol to the routing algorithm used. Routing Information Protocol Open Shortest Path First Border Gateway Protocol

Distance Vector Routing Link State Routing Path Vector Routing

In this (these) distributed routing algorithm(s), each node communicates ONLY with its immediate neighbors to "learn" about the other nodes on the network.

Distance Vector Routing Path Vector Routing

Check all that apply about connectionless services.

Each item carries all information needed to deliver it even if some links/nodes fail Intermediary nodes do not store any state about the offered service Items of the "same conversation" may take different paths.

Check all that apply to dynamic allocation of a broadcast channel with capacity C assuming there are n stations with n≥2

Each station can momentarily claim and use the full capacity C of the channel. At any point of time the sum of the capacities used by all stations is less or equal to C

Check all that apply to dynamic allocation of a broadcast channel with capacity C assuming there are n stations with n ≥ 2.

Each station can momentarily claim and use the full capacity CCof the channel. At any point of time, the sum of the capacities used by all stations is less or equal to C.

Check all that apply to static allocation of a broadcast channel with capacity C assuming there are n stations with n ≥ 2

Each station gets only a fraction (<1.0) of the full capacity of the broadcast channel. ONE MORE(divided between at least 2?)

Consider this network: bridge.png Hosts A, B, and DNS have MAC addresses Ea, Eb, and Ed, respectively. The bridge cache is initially empty: Consider this frame that was just sent: frameEaEb.png The bridge cache will add an entry for MAC address(es) __________.

Consider this network: bridge.png Hosts A, B, and DNS have MAC addresses Ea, Eb, and Ed, respectively. The bridge cache is initially empty: Consider this frame that was just sent: frameFFEb.png The bridge cache will add an entry for MAC address(es) __________.

Consider this network: bridge.png Hosts A, B, and DNS have MAC addresses Ea, Eb, and Ed, respectively. The bridge cache is initially empty: Consider this frame that was just sent: frameEbEd.png The bridge cache will add an entry for MAC address(es) __________. Ed Ea None of these answers Ec Eb

In this course, these metrics are used to evaluate the performance of error control protocols.

Efficiency Throughput

This issue is not a network software issue

Energy/Power management ------------------------------- Energy/Power management Addressing, naming Routing Error detection or correction None of these answers

_________ ________ is the design issue that consists of correcting errors in the received information.

Error correction

A sender wants to send the following payload (message) using Flag Bytes with Byte Stuffing: FLAG Y X FLAG R where letters A-Z represent bytes. The sender must build and send this frame as _________.

FLAG ESC FLAG Y X ESC FLAG R FLAG

A sender wants to send the following payload (message) using Flag Bytes with Byte Stuffing: Y X ESC R where letters A-Z represent bytes. The sender must build and send this frame as _________.

FLAG Y X ESC ESC R FLAG

A sender wants to send the following payload (message) using Flag Bytes with Byte Stuffing: Y X FLAG R where letters A-Z represent bytes. The sender must build and send this frame as _________.

FLAG Y X ESC FLAG R FLAG

Select the best answer. A sender wants to send the following payload (message) using Flag Bytes with Byte Stuffing: Y X FLAG R where letters A-Z represent bytes. The sender must build and send this frame as _________.

FLAG Y X ESC FLAG R FLAG

A receiver receives the following frame using Flag Bytes with Byte Stuffing: FLAG ESC FLAG Y X ESC FLAG R FLAG where letters A-Z represent bytes. The payload, i.e., the message, sent (without the stuffing if any) inside this frame is _________.

FLAG Y X FLAG R

A sender wants to send the following payload (message) using Flag Bytes with Byte Stuffing: Y X Z R where letters A-Z represent bytes. The sender must build and send this frame as _________.

FLAG Y X Z R FLAG

Check all frames that were sent by stations that do not comply to the Slotted Aloha protocol. [0 1.1 1.99 2 3]

FRAME 1, 2

Check all applications that use TCP. None of these answers Trivial FTP FTP HTTP SMTP DNS

FTP HTTP SMTP

BGP is likely used to update routing tables on Auburn University routers.

False

BGP is likely used to update routing tables on Auburn University routers.

False DELETE

Of the routing algorithms we studied, _______________ is the simplest one.

Flooding

With this routing algorithm, the node forwards each (unseen) packet on all outgoing interfaces, except the one the packet came in from.

Flooding

_________ is the design issue that consists of avoiding that a sender overwhelms a receiver.

Flow Control

Suppose that Slotted Aloha is used. Check all frames that will experience a collision. [0 1.1 1.99 2.2 4.3]

FrAme 1 and 2

Consider the table below that provides the time t R a frame is ready to be sent at a station. t Ris provided using as unit the transmission time T rof a frame. The first line provides the frame #. The second line provides the time t Rfor each frame. Frame #01234t R(in T r)01.9823.24.3 Suppose that Slotted Aloha is used. Check all frames that will experience a collision.

Frame # 1 Frame # 2

Consider the table below that provides the time t T a frame transmitted at a station. t Tis provided using as unit the transmission time T rof a frame. The first line provides the frame #. The second line provides the time t T for each frame. Frame #01234t T(in T r)01.11.9923 Check all frames that were sent by stations that do not comply to the Slotted Aloha protocol.

Frame # 2 Frame # 1

Consider the table below that provides the time t R a frame is ready to be sent at a station. t Ris provided using as unit the transmission time T rof a frame. The first line provides the frame #. The second line provides the time t Rfor each frame. Frame #01234t R(in T r)01.11.993.14.9 Suppose that Slotted Aloha is used. Check all frames that will experience a collision.

Frame #2 Frame #1

Consider the table below that provides the time t T a frame transmitted at a station. t Tis provided using as unit the transmission time T rof a frame. The first line provides the frame #. The second line provides the time t T for each frame. Frame #01234t T(in T r)134.46.18 Check all frames that were sent by stations that do not comply to the Slotted Aloha protocol.

Frame #2 Frame #3

Suppose that Pure Aloha is used. Check all frames that will experience a collision. (Frame#-Tr] [0-0,1-1.4,2-2.3,3-3.2,4-4.7]

Frame 0,1,2,3

Suppose that Slotted Aloha is used. Check all frames that will experience a collision. [0.45 0.98 2.3 3.2 4.3]

Frame 1 and 0

Suppose that Slotted Aloha is used. Check all frames that will experience a collision. [0-0,1-1.98,2-2,3-3.2,4-4.3]

Frame 1 and Frame 2

Suppose that Slotted Aloha is used. Check all frames that will experience a collision. [0-0,1-1.1,2-1.99,3-3.1,4-4.9]

Frame 1, frame 2

Suppose that Slotted Aloha is used. Check all frames that will experience a collision. [0-0,1-1.1,2-1.99,3-3.1,4-4]

Frame 1,2, and one more

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". We defined the probability P 0as having no collisions. We derived that the throughput is equal to ___________.

G . P 0 G . e − 2. G

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". We established that the throughput S (G . e − 2 G) for Pure Aloha is maximal for the value ___________.

G = 0.5

G = 1

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". If there are no retransmission, then the most likely relationships between N and G is ______________.

G = N

In order to evaluate the Slotted Aloha protocol We defined the probability LaTeX: P_0 P 0 as having no collisions. We derived that the throughput is equal to __

G.P0 G.e^-G

In order to evaluate the Slotted Aloha protocol. We established that the throughput S(Ge^-G) maximal for the value G

G=1

If there are no retransmission, then the most likely relationships between LaTeX: N N and LaTeX: G G is ______________.

G=N

Check all that apply to IEEE 802.5 (Token-Ring)

Has an excellent channel efficiency Guarantees upper bound on delivery time Is a kind of time division multiplexing MA

Check all that apply to contention-based multiple access protocols

Have a good average delivery time Do not offer an upperbound on the delivery time.

In the IPv4 header, the _________ field is used to detect corrupted bit(s) in the IP header of an IPv4 packet.

Header Checksum

DNS is a service that maps ______________ to ______________. None of these answers IP Addresses : MAC Addresses MAC Addresses : IP Addresses IP Addresses : Host Names Host Names : IP Addresses

Host Names : IP Addresses

Match these protocols in the TCP/IP reference model to some protocol they usually use in the layer below theirs. IP POP3 UDP FTP DNS

IEE 802.11 TCP (Almost certain this is right) IP TCP (Almost certain this is right) UDP (Almost certain this is right)

Check the protocol(s) that belong(s) to the presentation layer

IEEE 754

A wireless LAN uses most likely the ________ standard.

IEEE 802.11

Wifi uses the ____________ standard.

IEEE 802.11

Your wireless network at home (to access the Internet) uses most likely the ________ standard.

IEEE 802.11

Check the protocol(s) that belong(s) to the physical layer

IEEE 802.11 IEEE 802.3

A popular wireless MAN uses the ___________ standard.

IEEE 802.16

Ethernet uses the ____________ standard.

IEEE 802.3

These (this) protocol(s) are contention based protocols.

IEEE 802.3 IEEE 802.11

Match these protocols in the TCP/IP reference model to some protocol they use in the layer below theirs. IP IMAP TCP Trivial File Transfer Protocol SMTP

IEEE 802.3 TCP IP UDP TCP PARTIAL(2.6/3.25) IP -- POP3 (IEEE 802.3 was not in the option list) IMAP -- TCP UDP -- IP Trivial File Transfer Protocol -- UDP ESMTP -- TCP

Check the protocol(s) that belong(s) to the data link layer

IEEE 802.3 IEEE 802.11

These (this) IEEE 802.x protocol(s) are fully collision free.

IEEE 802.4 IEEE 802.5

A DNS server uses ________ at the network (internet) layer.

A DNS server uses ________ at the network (internet) layer. Port 53 TCP IP Port 35 UDP

The Border Gateway Protocol (BGP) uses _______ as its network protocol.

The Open Shortest Path First protocol (OSPF) uses _______ as its network protocol.

The Routing Information Protocol (RIP) uses _______ as its network protocol.

Most hosts on the Internet will have these protocols active on them. DHCP server IP none of these answers UDP DNS server DNS client

IP DNS client UDP DELETE

These are routing mechanisms

IP Hot Potato Early Exit

This (these) protocol(s) are used at the Internet (Network) layer in the TCP/IP Reference model.

IP ICMP (multiple versions - may only have one of these options listed)

These are routing mechanisms.

IP early exit hot potato

Match these protocols to their layers in the TCP/IP reference model. IP UDP TCP HTTP DNS POP3 UDP FTP SMTP

IP -- Internet (network) UDP -- Transport TCP -- Transport HTTP -- Application DNS -- Application POP3 -- Application FTP -- Application SMTP -- Application (Some may not appear)

Check the information that a DHCP Server provides. IP address of DNS server Subnet mask IP address None of these answers Name of the DNS Server IP address of gateway router

IP address IP address of gateway router Subnet mask IP address of DNS server

In general, these protocols/services may use directly or indirectly a DNS client. SMTP server SMTP client POP3 server telnet client telnet server POP3 client None of these

IS SMTP client (2 more options) NOT None of these NOT (HTTP server, ssh Server, DNS server) NOT (ssh client, DNS client)

Check all that apply about a broadcast channel ___________________________ .

If only one station emits, all other stations hear . If two or more stations emit, all other stations hear If only one station emits, all other stations hear and understand .

Check all that apply about a broadcast channel

If only one station emits, all other stations hear . If two or more stations emit, all other stations hear If only one station emits, all other stations hear and understand .

Check all that apply about a broadcast channel ___________________________ . If two or more stations emit, all other stations hear If only one station emits, all other stations hear and understand . If two or more stations emit, all other stations hear and understand If only one station emits, all other stations hear . None of these answers.

If two or more stations emit, all other stations hear If only one station emits, all other stations hear and understand . If only one station emits, all other stations hear .

Check all true statements when forward error correction (FEC) is used at the receiver. The channel is supposed to be only noisy (i.e., error-prone). timeout is not anymore needed None of these answers. The receiver does not have to retransmit Acknowledgements are not anymore necessary. In general, the sender does not have to retransmit

In general, the sender does not have to retransmit

Consider the method DatagramPacket(a,b,c,d). The type of the parameter c is ____________ assuming that d is a port number.

InetAddress

Check all statements/method calls that TCP server or client must absolutely include to receive data using I/O streams a and b. The TCP server or client uses the socket variable sock. b.write(...) None of these answers b.read(......) InputStream a = sock.getInputStream(); OutputStream b = sock.getOutputStream();

InputStream a = sock.getInputStream();

Select all that apply. Check all statements/method calls that TCP server or client must absolutely include to receive data using I/O streams a and b. The TCP server or client uses the socket variable sock. -b.write(...) -None of these answers -b.read(......) -InputStream a = sock.getInputStream(); -OutputStream b = sock.getOutputStream();

InputStream a = sock.getInputStream();

Check all that applies to this frame "sniffed" on the medium (expressed in hexadecimal. Preamble is not included): 76 3E 56 E2 08 00 08 06 80 35 08 06 08 00 45 7F 05 4E 5C 4B EE DD12 06 10 E5 83 CC 0E 37 83 CC 0E 40 27 1A 27 D7 00 00 12 05 10 E2 00 34 .. Below are the frame and IP headers: It contains an IPv6 packet Correct! It contains an IP packet WITHOUT options None of these answers It contains a UDP datagram Correct! It contains an IPv4 packet Correct! It contains a TCP segment

It contains an IP packet WITHOUT options It contains an IPv4 packet It contains a TCP segment

Check all that applies to this frame "sniffed" on the medium (expressed in hexadecimal. Preamble is not included): 76 3E 56 E2 08 00 08 06 80 35 08 06 08 00 47 7F 05 4E 5C 4B EE DD 12 06 10 E5 83 CC 0E 37 83 CC 0E 40 27 1A 27 D7 00 00 12 05 10 E2 00 34 ..

It contains an IPv4 packet It contains a TCP segment

Check all that applies to this frame "sniffed" on the medium (expressed in hexadecimal. Preamble is not included): 76 3E 56 E2 08 00 08 06 80 35 08 06 08 00 45 7F 05 4E 5C 4B EE DD 12 11 10 E5 83 CC 0E 37 83 CC 0E 40 27 1A 27 D7 00 00 12 05 10 E2 00 34 .. Below are the frame and IP headers:

It contains an IPv4 packet It contains an IP packet WITHOUT options It contains a UDP datagram

Check all that applies to this frame "sniffed" on the medium (expressed in hexadecimal. Preamble is not included): 76 3E 56 E2 08 00 08 06 80 35 08 06 86 DD 65 7F 05 4E 5C 4B EE DD 12 11 10 E5 83 CC 0E 37 83 CC 0E 40 27 1A 27 D7 00 00 12 05 10 E2 00 34 ..

It contains an IPv6 packet

Check all that applies to this frame "sniffed" on the medium (expressed in hexadecimal. Preamble is not included): 76 3E 56 E2 08 00 08 06 80 35 08 06 08 00 47 7F 05 4E 5C 4B EE DD 12 11 10 E5 83 CC 0E 37 83 CC 0E 40 27 1A 27 D7 00 00 12 05 10 E2 00 34 ..

It is a DIX frame It contains an IPv4 packet It contains a UDP datagram

Check all that applies to the Nyquist Theorem.

It limits the baud (symbol) rate Its limit is different for different media

Check all that apply about connection-oriented service(s).

It requires circuit set up

IP addresses

It uniquely identifies a network interface

The function call Socket is used by a

Java TCP Client. (None if options are only UDP)

This Internet pioneer was an editor or an author for the original RFCs specifying IP, UDP, TCP, and SMTP

Jon Postel

Your wireless network at home is a _____

LAN

Medium Access Control is important and used mainly for ___________.

LANs (Local Area Networks)

In the TCP/IP Reference Model, a bridge uses this (these) layer(s) when carrying a conversation. Transport Application Session Link None of these answers Presentation Internet/Network

Link

In the TCP/IP Reference Model, an L2 switch uses this (these) layer(s) when carrying a conversation. Link Transport Session Presentation None of these answers Internet/Network Application

Link

In the TCP/IP Reference Model, these layers are mostly implemented by hardware on most hosts (clients or servers). Internet/Network Presentation Transport Session Link Application None of these answers

Link

In the TCP/IP Reference Model, your Bluetooth interface uses this (these) layer(s) when you are browsing the Internet.

Link

In the TCP/IP Reference Model, a router uses this (these) layer(s) when carrying a conversation. None of these answers Link Transport Application Presentation Internet/Network Session

Link Internet/Network

In the TCP/IP Reference Model, an L3 switch uses this (these) layer(s) when carrying a conversation.

Link Internet/Network

In the TCP/IP Reference Model, a router uses this (these) layer(s) when carrying a conversation. Application Transport Link None of these answers Internet/Network Presentation Session

Link Internet/Network DELETE

In the TCP/IP Reference Model, your laptop uses this (these) layer(s) when you are browsing the Internet (using an application like Firefox, Chrome, or Internet Explorer). Presentation Link Session Transport None of these answers Application Internet/Network

Link Transport Application Internet/Network

In this (these) distributed routing algorithm(s), each node communicates will all other nodes about its distance to its immediate neighbors only.

Link State Routing

The medium access control sublayer provides service directly to the

Logical link sublayer

Check all frames that were sent by stations that do not comply to the Slotted Aloha protocol. [ 1 3 4 6 8]

MAYBE FRAME 2 and 3

In the context of OSI Reference Model (Data Link Layer), the MAC stands for ________________________________.

Medium Access Control

This word, sent using odd parity, is received. Word = 1011 1011 1 Was the word corrupted?

Maybe

Consider a system with frame size and bit rate. If the unit Tr as unit, then 0.5s = 1s =

Maybe 0.0005, 0.001

1000 us=

Maybe 1000000, NOT 10, NOT 1

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". Suppose that the traffic (new frames) is quite heavy (e.g., N > 0.9), then the most likely relationships between N and G is ______________.

N < G

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". Suppose that the traffic (new frames) is quite heavy (e.g., N > 0.9), then the most likely relationships between N and G is ______________. None of these answers G < 0.3 ⋅ N N < G N > G N ≈ G

N < G

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". Suppose that the traffic (new frames) is quite light (e.g., N < 0.3), then the most likely relationships between N and G is ______________.

N ≈ G

N ≈ G N < G G = N

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". Check all possible relationships between N and G. N > G N ≈ G None of these answers N < G G = N

N ≈ G N < G G = N

Assume that the channel can corrupt up to one bit. The word 1011 1101 is received using the Hamming code C. The original word that was most likely sent originally (before corruption) was _____________. Code C uses four codewords L, M, N, and O defined as follows: Code C: L : 0000 0000 M: 0100 1011 N: 1011 0101 O: 1111 1010

N: 1011 0101

Suppose that the traffic (new frames) is quite heavy (e.g., N>0.9), then the most likely relationships between N and G is ______________.

N<G

A host H has IP address A represented in dotted-decimal as 120.204.14.65. Select the instruction that computes the network ID NID of IP Address A.

NID = A & 0xff000000

A host H has IP address A represented in dotted-decimal as 56.204.14.65. Select the instruction that computes the network ID NID of IP Address A.

NID = A & 0xff000000

A host H has IP address A represented in dotted-decimal as 56.204.14.65/9. Select the instruction that computes the network ID NID of IP Address A.

NID = A & 0xff800000

A host H has IP address A represented in dotted-decimal as 120.204.14.65/11. Select the instruction that computes the network ID NID of IP Address A.

NID = A & 0xffe00000

A host H has IP address A represented in dotted-decimal as 56.204.14.65/13. Select the instruction that computes the network ID NID of IP Address A.

NID = A & 0xfff80000

A host H has IP address A represented in dotted-decimal as 56.204.14.65/15. Select the instruction that computes the network ID NID of IP Address A.

NID = A & 0xfffe0000

A host H has IP address A represented in dotted-decimal as 128.204.14.65. Select the instruction that computes the network ID NID of IP Address A.

NID = A & 0xffff0000

A host H has IP address A represented in dotted-decimal as 191.204.14.65. Select the instruction that computes the network ID NID of IP Address A. NID = A & 0x00000000 NID = A & 0xff000000 NID = A & 0xffffff00 None of these answers NID = A & 0xffff0000

NID = A & 0xffff0000

A host H has IP address A represented in dotted-decimal as 191.204.14.65/20. Select the instruction that computes the network ID NID of IP Address A.

NID = A & 0xfffff000

Consider the table below that provides the time t R a frame is ready to be sent at a station. t Ris provided using as unit the transmission time T rof a frame. The first line provides the frame #. The second line provides the time t Rfor each frame. Frame #01234t R(in T r)01.12.13.24.1 Suppose that Pure Aloha is used. Check all frames that will experience a collision.

NOT Frame #1 Frame #2 Frame #3

Consider this network: router.png Hosts A, B, C, and DNS have MAC addresses Ea, Eb, Ec, and Ed, respectively. The bridge cache is as follows: MAC Addresses Ports Ed P2 Ea P1 Consider this frame that was just sent: frameEaEb.png Besides its sender, this frame is seen by Host(s) _____________ . None of these answers A DNS C B Router Interface on Segment 1 Router Interface on Segment 3

NOT (A, DNS) NOT (A, B)

In the TCP/IP Reference Model, the wireless network interface on your laptop/desktop uses this (these) layer(s) when you are browsing the Internet. Session Application Link Presentation Transport Internet/Network None of these answers

NOT (Application, Link, Transport, Internet/Network)

Consider this network: router.png Hosts A, B, C, and DNS have MAC addresses Ea, Eb, Ec, and Ed, respectively. The bridge cache is initially empty: Consider this frame that was just sent: frameEbEd.png Besides its sender, this frame is seen by Host(s) _____________ . DNS Router Interface on Segment 1 None of these answers A B Router Interface on Segment 3 C

NOT (DNS, B)

In the TCP/IP Reference Model, a bridge uses this (these) layer(s) when carrying a conversation. None of these answers Session Presentation Transport Link Internet/Network Application

NOT (Transport, Link, Internet/Network, Application)

Check all techniques we studied earlier that can in general be used for detecting and correcting up to two corrupted bits. crossed parities adding a parity bit None of these answers. Hamming codes with distance 5 Hamming codes with distance 4

NOT (crossed parities, Hamming codes with distance 5, Hamming codes with distance 4) NOT crossed parities

Consider a system using a frame size equal to 1500 bytes. The bit rate is 1.2 Mbps. Assume that the unit used to measure time is equal to the time Tr to send a frame. If we use the unit Tr as unit, then 1 ms = _______________ Tr.

NOT 0.01

Today, most wired LANS run at speeds from ________ up to ________ .

NOT 1 Mbps up to 100 Gbps (both could be wrong, or just one could be wrong)

Consider a system with frame size and bit rate. If the unit Tr as unit, then 1 ms =

NOT 1, NOT 100

NOT 5

A DNS client binds to Port # _______.

NOT 53 ------------------------ None of these answers

In the OSI Reference Model, your wireless network interface uses this (these) layer(s) when you are browsing the Internet. Application Session Internet / Network Presentation Transport Physical Data Link / Link

NOT Data Link/ Link NOT Internet/ Network Not Internet/Network, Data Link / Link, Transport, & Application

This (These) protocol(s) is (are) routing protocol(s) (modifying routing tables) that could be used on the Internet backbone. Group of answer choices None of these answers Border Gateway Protocol (BGP) Internet Protocol (IP) Open Shortest Path First (OSPF) Routing Information Protocol (RIP)

NOT Internet Protocol (IP) DELETE

Check all frames that were sent by stations that do not comply to the Slotted Aloha protocol.

NOT NONE MAYBE FRAME 1

This question explores the time to send and acknowledge a frame with n bits when using retransmission or forward error correction on a noisy (error-prone) channel. When using retransmission, the frame is padded with m check bits while with forward error correction, the frame is padded with m' bits with m ′ > m. When using forward error correction, the time between when a sender receives a positive acknowledgement and when it sends the frame is about _______________ assuming a propagation time T p and a bit rate b e r. We assume that forward error correction always succeeds to correct.

NOT None of these answers

Check the action(s) consistent with (i.e., respecting the rules of) the Stop-And-Wait protocol. Send a new frame after a timeout Stop receiving after a timeout Send a new frame after a failed transmission None of these answers Send the same frame after receiving an acknowledgement Send the same frame after a failed transmission

NOT None of these answers 0/8.25 Stop receiving after a timeout Send a new frame after a timeout

The ______________________________ is the distribution that represents the most accurately data traffic (i.e., bursty traffic). Poisson probability distribution uniform probability distribution exponential probability distribution None of these answers. bursty probability distribution

NOT Poisson probability distribution NOT exponential probability distribution

Check the transport layer protocol(s) used for the delivery of an email from a Message Transfer Agent to a Receiver User Agent.

NOT SMTP NOT UDP NOT None NOT (POP3, IMAP)

Check all true statements

NOT UDP identifies upper processes (applications) using the IP address NOT TCP identifies upper processes (applications) using the IP address

Check all features/services ESMTP allows/offers.

NOT Used to encrypt and transfer data from the Message Transfer Agent to the Receiver User Agent NOT Used to encrypt and transfer encrypted data from the Sender User Agent to the Message Transfer Agent

This issue is not a network software issue Congestion or flow control Confidentiality or authentication Routing None of these answers Scalability

None of these answers

Check all features/services ESMTP allows/offers.

NOT Used to transfer data in plain from to a Message Transfer Agent to a Message Transfer Agent PARTIAL 5/10 Encrypts and transfers ASCII text Used to transfer data in plain from to a Message Transfer Agent to a Message Transfer Agent Used to encrypt and transfer encrypted data from the Sender User Agent to the Message Transfer Agent PARTIAL (1.5/3) Encrypts and transfers ASCII text

Check all techniques we studied earlier that can in general be used for detecting up to two corrupted bits. adding a parity bit Hamming codes with distance 2 crossed parities None of these answers. Hamming codes with distance 3

NOT adding a parity bit NOT Hamming codes with dist 2 NOT crossed parities Not hamming codes with dist 3

Check all features that TCP offers while UDP does NOT.

NOT congestion control NOT addressing NOT guaranteed throughput

Consider a system using a frame size equal to 1500 bytes. The bit rate is 1.2 Mbps. Assume that the unit used to measure time is equal to the time Tr to send a frame. If we use the unit Tr as unit, then 0.5 ms = _______________ Tr.

NOt 0.005

In the OSI reference model, IP belongs to the _______________ layer.

Network

In the OSI reference model, the [name1] layer provides service directly to the transport layer.

Network

In the OSI reference model, the [name1] layer receives service directly from the data link layer.

Network

Check all frames that were sent by stations that do not comply to the Pure Aloha protocol. [1 3.5 4.1 6 8]

None

Check all frames that were sent by stations that do not comply to the Pure Aloha protocol. [1.2 3.67 4.15 6.53 8]

None

Check all statements that apply to the Pure Aloha protocol.

None

Consider the table below that provides the time t_T a frame transmitted Check all frames that were sent by stations that do not comply to the Pure Aloha protocol. [1 3 4.15 6.53 8]

None

In order to evaluate the Pure Aloha protocol and Slotted Aloha, we defined the probability P_0 as having no collisions. We observed that this probability is equal to the probability of 2 transmitted frames during _____ unit(s) time. Recall we are using the transmission time T_r as unit.

None

Suppose that Pure Aloha is used. Check all frames that will experience a collision. [0.5 2.6 3.5 4.7 5.8]

None

Suppose that Pure Aloha is used. Check all frames that will experience a collision. (Frame#-Tr] [0-0.5,1-2.4,2-3.5,3-4.7,4-5.8]

None

Suppose that Slotted Aloha is used. Check all frames that will experience a collision. [0 1.4 2.3 3.2 4.7]

None

Suppose that Slotted Aloha is used. Check all frames that will experience a collision. [0-0,1-1.1,2-2.1,3-3.2,4-4.1 or 4.2]

None

Suppose that Slotted Aloha is used. Check all frames that will experience a collision. [0-0.5,1-1.6,2-3.8,3-4.8,4-5.3]

None

Check all applications that UDP uses. Trivial FTP IMAP None of these answers Telnet ssh DNS

None of these Answers

For DNS, the domain name "cisco" is defined under the domain .com (to form cisco.com). These domains can not use the domain cisco under them. edu None of these answers us museum net

None of these Answers

Using DNS, each domain name (i.e., edu, cisco.com, cs.washington.edu, tamu.edu, cs.tamu.edu, .....) must have at least ________ name server(s).

None of these Answers

A network is made of 16 nodes using a broadcast medium. These nodes use distance vector routing. Suppose these nodes turn on at the same time. How many rounds of communications are needed for all the nodes to update their routing tables with ALL nodes in the network.

None of these answers

A receiver receives the following frame using Flag Bytes with Byte Stuffing: FLAG FLAG Y X ESC FLAG R FLAG where letters A-Z represent bytes. The payload, i.e., the message, sent (without the stuffing if any) inside this frame is _________. ESC Y X FLAG R Y X ESC ESC R None of these answers Y X FLAG R Y X ESC FLAG R

None of these answers

A user types the command "arp -a" on the console of the machine csexmac161engauburnedu. The arp command displays (see picture) the content of the ARP cache of the machine csexmac161engauburnedu. Suppose that IP on this machine must send a packet to the interface with IP Address 192.168.1.124. When IP asks ARP for the address 192.168.1.124, ARP will return the MAC address ________________.

None of these answers

Check all applications that TCP uses. Trivial FTP None of these answers FTP DNS SMTP HTTP

None of these answers

Check all that apply The function call datagramsocket is used by a ________________. Pay attention! Java is case sensitive. a. Java UDP client to exchange data with a Java UDP server b. None of these answers c. Java UDP Server to exchange data with a Java UDP client d. Java UDP server to initiate a connection with a UDP client e. Java UDP Client to initiate a connection with a UDP server

None of these answers

The function call socketclient is used by a __. a. Java TCP Server to exchange data with a TCP client b. Java TCP Client to initiate a TCP connection with a server c. Java TCP Client to exchange data d. None of these answers e. Java TCP Server to establish a TCP connection

None of these answers

The method DatagramPacket(a, b, c, d) returns a result of type _________. a. InetAddress b. int c. None of these answers d. byte[] e. DatagramSocket

None of these answers

Check all that apply. The function call socketserver is called by a ________________. (Pay attention! Java is case sensitive) -Java TCP Server to establish a TCP connection -Java TCP Client to establish a TCP connection -None of these answers -Java TCP Server to establish a server -Java TCP Client to exchange data with a TCP server

None of these answers

Check the information that a DHCP Client provides.

None of these answers

Consider a sender and a receiver connected using an ideal (error-free) channel. Assuming that the sender does not retransmit, check all required countermeasures to insure reliable communications.

None of these answers

Consider the table below that provides the time t R a frame is ready to be sent at a station. t Ris provided using as unit the transmission time T rof a frame. The first line provides the frame #. The second line provides the time t Rfor each frame. Frame #01234t R(in T r)0.51.63.84.25.3 Suppose that Slotted Aloha is used. Check all frames that will experience a collision.

None of these answers

Consider the table below that provides the time t R a frame is ready to be sent at a station. t Ris provided using as unit the transmission time T rof a frame. The first line provides the frame #. The second line provides the time t Rfor each frame. Frame #01234t R(in T r)0.51.634.25.3 Suppose that Pure Aloha is used. Check all frames that will experience a collision.

None of these answers

Consider the table below that provides the time t R a frame is ready to be sent at a station. t Ris provided using as unit the transmission time T rof a frame. The first line provides the frame #. The second line provides the time t Rfor each frame. Frame #01234t R(in T r)0.52.43.54.75.8 Suppose that Pure Aloha is used. Check all frames that will experience a collision. Frame # 2 Frame # 0 None of these answers Frame # 3 Frame # 1

None of these answers

Consider the table below that provides the time t T a frame transmitted at a station. t Tis provided using as unit the transmission time T rof a frame. The first line provides the frame #. The second line provides the time t T for each frame. Frame #01234t T(in T r)1.753.54.16.58 Check all frames that were sent by stations that do not comply to the Pure Aloha protocol.

None of these answers

Consider this code snapshot: String str = new String("CD456"); byte[] a = str.getBytes("UTF-16"); The content of a[1] is ___________. 68 54 Invalid None of these answers 52 67 0

None of these answers

Consider this code snapshot: String str = new String("CD456"); byte[] a = str.getBytes("UTF-16BE"); The content of a[7] is ___________. a. 67 b. Invalid c. 54 d. 52 e. 0 f. None of these answers

None of these answers

Consider this incomplete code snapshot: int a, e; long h; short b, f; byte g; DataOutputStream c; DatagramSocket d; InputStream m; ByteArrayOutStream x = new ByteArrayOutputStream(); c = new DataOutputStream(x); DataInputStream v = new DataInputStream(m); Select any valid statement. a. f = c.readLong(); b. f = v.readLong(); c. None of these answers d. f = v.readInt(); e. f = c.readInt();

None of these answers

DNS is a service that maps ______________ to ______________. Host names : Port Numbers MAC Addresses : IP Addresses IP Addresses : MAC Addresses Port Numbers : Host Names None of these answers

None of these answers

In order to evaluate the Pure Aloha protocol, we defined the probability P 0as having no collisions. We observed that this probability is equal to the probability of 1 transmitted frame during _____ unit(s) time. Recall we are using the transmission time T r as unit.

None of these answers

In order to evaluate the Pure Aloha protocol, we defined the probability P 0as having no collisions. We observed that this probability is equal to the probability of 2 transmitted frames during _____ unit(s) time. Recall we are using the transmission time T r as unit. 2 3 1 None of these answers 0

None of these answers

In the IPv4 header, the _________ field is used to detect corrupted bit(s) in an IPv4 packet. fragment offset None of these answers protocol identification Header Checksum

None of these answers

In the OSI reference model, the transport layer does not provide/perform this (these) service/function(s).

None of these answers

In the TCP/IP Reference Model, a repeater fully uses this (these) layer(s) when carrying a conversation. Presentation Internet/Network Application Session Transport None of these answers Link

None of these answers

In the TCP/IP Reference Model, a repeater uses this (these) layer(s) when carrying a conversation.

None of these answers

In the TCP/IP model, TCP uses this (these) protocol(s) at the application layer.

None of these answers

In the TCP/IP model, UDP uses this (these) protocol(s) at the application layer.

None of these answers

In the TCP/IP reference model, UDP belongs to the _______________ layer.

None of these answers

Point-to-point channels are sometimes referred to as ___________________________ .

None of these answers

The class of IP Address 254.20.14.53 is _________.

None of these answers

The function call SocketServer is called by a ________________. a. Java TCP Server to accept a connection with a TCP client b. None of these answers c. Java TCP Client to exchange data with a TCP server d. Java TCP Server to exchange data with a TCP client e. Java TCP Client to initiate a connection with a TCP server

None of these answers

This question is related to the performance evaluation of the Stop-And-Wait protocol on an error-free channel. Refer to the figure to answer. Let P s and b r be the packet size (in bits) and the bit rate (in bits/s), respectively. Assuming that we neglect the processing time of a received packet and the transmission time of an acknowledgement, the throughput in packets/s is equal to _______________.

None of these answers

DNS is a service that maps ______________ to ______________. None of these answers Host names : Port Numbers IP Addresses : MAC Addresses MAC Addresses : IP Addresses Port Numbers : Host Names

None of these answers (If it were an option, the answer would be Host names : IP Addresses)

This question is related to the performance evaluation of the Stop-And-Wait protocol on an error-free channel. Refer to the figure to answer. Let P s and b rbe the packet size (in bits) and the bit rate (in bits/s), respectively. Assuming that we neglect the processing time of a received packet and the transmission time of an acknowledgement, the throughput in bytes/s is equal to _______________.

None of these answers NOT (Ps/8)/(2Tp+(Ps/8)/br) Ps/(Tp + (8/br) + Tp) (Ps/8)/2Tp + (8/br) (Ps/8)/(Tp+Tr+Ct+Ta+Tp) 8/(2Tp+(8/br))

A host H has IP address 56.204.14.65. Suppose you want to send some packet to all hosts on the same network as H . You could use this (these) addresses. None of these answers 56.204.255.255 56.204.14.255 255.204.14.65 56.204.14.0

None of these answers (I think it would just be 56.255.255.255)

In the OSI reference model, an instance in the network layer wants to send a data unit m. The first header added to m will be a header belonging to the ________ layer.

None of these answers (data link)

None of these answers (would be -||w||^2)

Consider a sender and a receiver connected using a noisy (corruption-prone) channel. Assuming that the sender does not retransmit, check all required countermeasures at the sender to insure reliable communications. ack for well received packets error correction timeout ack for losses error detection None of these answers.

None of these answers.

Select the best answer. Wireless communications use ____________________ as a medium. fiber optics cable None of these choices twisted pairs ethernet cables

None of these choices

The ______________________________ is the distribution that represents the most accurately data traffic (i.e., bursty traffic).

Not bursty, not poisson,, Try None

Suppose that a function f(x) reaches its maximal value for some value LaTeX: x_{\max} If LaTeX: x_{\max} exists then the maximal value of f(x) is ________________

Not dfx/dx is solution for fxmax =0

Suppose that the traffic (new frames) is quite light (N < 0.3) then most likely relationships between N and G

N~G

Check all possible relationships between N and G

N~G, G =N, N<G

A local area network (LAN) is a network covering typically _____

One small campus One room One small building

This (These) protocol(s) is (are) routing protocol(s) (modifying routing tables) that could be used on autonomous systems (i.e., not on the Internet backbone).

Open Shortest Path First (OSPF) Routing Information Protocol (RIP)

Optical fiber - 1 Coaxial cable - 2 Twisted pairs - 3 Satellite links - 99 Terrestrial microwave - 99

Check all statements/method calls that TCP server or client must absolutely include to send data using I/O streams a and b. The TCP server or client uses the socket variable sock. -InputStream a = sock.getInputStream(); -OutputStream b = sock.getOutputStream(); -None of these answers -a.write(...) -b.read(.......)

OutputStream b = sock.OutputStream();

Check all statements/method calls that TCP server or client must absolutely include to send data using I/O streams a and b. The TCP server or client uses the socket variable sock. -b.write(...) -None of these answers -OutputStream b = sock.getOutputStream(); -InputStream a = socker.getInputStream(); -b.read(......)

OutputStream b = sock.getOutputStream(); b.write(...)

Bluetooth is a technology that could work for these types of networks

PAN (Personal Area Network) LAN (Local Area Network)

PARITAL (6.67 / 10 pts) The average delay with static allocation is larger than with dynamic allocation With static allocation, there is an upper bound on the delay to deliver a packet

______________ links connect individual pairs of machines.

PARTIAL NOT bus

Consider a sender and a receiver connected using a real life channel. Assuming that the sender does not retransmit corrupted packets, check all required countermeasures at the receiver to insure reliable communications. None of these answers. timeout error detection error correction retransmission ack for losses ack for well received packets

PARTIAL (13.33/20) error detection error correction

Suppose a DNS client must resolve the host name toto.acm.org. Assign to each name server on the left a sequence number n based on the order it is queried. The first queried name server must be assigned the sequence number 1. Assign 99 to a name server that is not queried. root Nacm Norg Nwas Local name server

PARTIAL (2/5): 99 99 99 99 1

Consider a sender and a receiver connected using a real life channel. Assuming that the sender does not retransmit corrupted packets, check all required countermeasures to insure reliable communications. None of these answers. retransmission ack for well received packets ack for losses timeout error detection error correction

PARTIAL (4/20) retransmission PARTIAL(6/10): error correction ack for losses ack for well received packets error detection retransmission

Check the application layer protocol(s) used for the submission of an email by the Sender User Agent to the Message Transfer Agent.

PARTIAL (5/10) SMTP

Check all weaknesses of static allocation of a broadcast channel with capacity C assuming there are n stations with n ≥ 2. The average delay to send a packet is higher than with dynamic allocation . Each channel may be underutilized. None of these answers. Static allocation is inefficient for regular (rather than bursty) traffic.. Collisions over each allocated channel will consume all the available channel capacity.

PARTIAL (5/10) The average delay to send a packet is higher than with dynamic allocation . Each channel may be underutilized. Static allocation is inefficient for regular (rather than bursty) traffic..

Check all that apply to dynamic allocation of a broadcast channel with capacity C assuming there are n stations with n ≥ 2. -Each station gets only a fraction (<1.0) of the full capacity of the broadcast channel. -The capacity C is divided between at least two channels . -At any point of time, the sum of the capacities used by all stations is less or equal to C. -None of these answers. -Each station can momentarily claim and use the full capacity C of the channel.

PARTIAL (5/10): Each station can momentarily claim and use the full capacity CC of the channel.

Check all techniques we studied earlier that can in general be used for detecting corrupted messages. crossed paritie schecksum Hamming codes Cyclic Redundancy Check adding a parity bit None of these answers. checkbyte

PARTIAL (5/12.5) checksum Hamming codes 7.5 / 12.5 pts checksum Hamming Codes Cyclic Redundancy Check

This question is about how the Internet Protocol (IP) handles a packet P and decides where to deliver it. Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.64.159. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.254 read the routing table ask ARP for the MAC address corresponding to IP Address 134.89.200.67 ask ARP for the MAC address corresponding to IP Address 134.89.200.254 check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.67 ask ARP for the MAC address corresponding to IP Address 131.89.200.254

PARTIAL (5/7): 0 2 0 0 1 0 0

Check all methods that can improve the raw (digital) transmission of bits over long distances. Use encoding schemes such as NRZ, NRZI, or Manchester delay the signal Use wireless channels Use media more prone to interferences Amplify a signal at the source Improve the quality of the medium Modulate the signal

PARTIAL (8.33/12.5): Use encoding schemes such as NRZ, NRZI, or Manchester Improve the quality of the medium

These are the underlying design constraints that resulted in what the OSI Reference Model is today

PARTIAL - 3.13/6.25 The flow of information through interfaces must be minimal NOT The flow of information through protocols must be minimal.

Check all techniques we studied earlier that can in general be used for detecting up to one corrupted bit. adding an odd parity bit adding an even parity bit Cyclic Redundancy Check crossed parities checksum None of these answers. Hamming codes with distance 1

PARTIAL 10/12.5 adding an odd parity bit adding an even parity bit crossed parities checksum

Consider a sender and a receiver connected using a real life channel. Assuming that the sender retransmits corrupted packets, check all required countermeasures at the receiver to insure reliable communications.

PARTIAL 10/20 ack for well received packets error detection ack for losses

This question is about how the Internet Protocol (IP) handles a packet P and decides where to deliver it. Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.65.172. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.54 read the routing table ask ARP for a MAC address corresponding to IP Address 134.89.200.67 ask ARP for a MAC address corresponding to IP Address 131.89.200.254 check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.67

PARTIAL 2.67/4 0 2 0 0 1 0

This question is about how the Internet Protocol (IP) handles a packet P and decides where to deliver it. Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.194.65.170. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.128 read the routing table ask ARP for the MAC address corresponding to IP Address 134.89.200.128 ask ARP for the MAC address corresponding to IP Address 131.89.200.54 check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.54

PARTIAL 2.6l7/4 0 2 0 0 1 0 PARTIAL 6.67/20 0 2 0 3 1 4 PARTIAL 1.33/4 0 2 0 4 1 3

In the TCP/IP Reference Model, these layers are mostly implemented by software on most hosts (clients or servers).

PARTIAL 4.17/6.25 Application Internet/Network Transport Link

This question is about how the Internet Protocol (IP) handles a packet P and decides where to deliver it. Consider a device D with IP address 134.89.200.145/24. On Device D, IP is handed a packet P with a destination IP address 131.204.65.171. Provide the order in which IP on Device D will perform these actions. The earliest action must be assigned 1. Any action that is incorrect or is not performed must be assigned the number 0. send Packet P to the device with IP address 134.89.200.67 read the routing table ask ARP for a MAC address corresponding to IP Address 134.89.200.54 ask ARP for a MAC address corresponding to IP Address 131.89.200.67 check if the IP destination address of Packet P is local send Packet P to the device with IP address 134.89.200.254

PARTIAL 6.67/20 0 2 3 0 1 4 PARTIAL 13.33/20 3 2 0 0 1 0

Consider a sender and a receiver connected using a real life channel. Check all required countermeasures at the sender to insure reliable communications. retransmission ack for losses error correction ack for well received packets error detection timeout None of these answers.

PARTIAL(10/20) retransmission

Consider a sender and a receiver connected using a noisy (corruption-prone) channel. Assuming that the sender does not retransmit, check all required countermeasures at the receiver to insure reliable communications. timeout error correction retransmission ack for losses None of these answers. ack for well received packets error detection

PARTIAL(13.33/20) error correction error detection PARTIAL (4/6) error detection ack for well received packets

Fill in multiple blanks. This exercise is about framing. The following character encoding is used in a data link protocol: X: 01000111 Y: 11100111 FLAG: 01111110 ESC:11100111 Show the bit sequence transmitted (in binary) for the four-character frame X Y ESC FLAG when byte counting is used. Pay attention to the order. Fill in the following 8-bit groups. Some groups at the end may have less than 8 bits. If the group is empty, fill it with "-" (ONE minus character).

PARTIAL(5.36/12.5): 01000111 ;11100111 ;11100111 ;01111110 ;- ;- ;- (Probably 00000101; 01000111 ;11100111 ;11100111 ;01111110 ;- ;-)

This Internet pioneer was the first to invent (mention) the concept of a packet (packet switching).

Paul Baran

On an Ethernet frame, the ________ field will contain an IP packet, an ARP request/response, or other network protocols data units. Destination Source Payload Type CRC None of these answers

Payload

In the OSI Reference Model, a repeater uses this (these) layer(s) when carrying a conversation.

Physical

The MAC sublayer gets service directly from the

Physical

In the OSI Reference Model, a bridge uses this (these) layer(s) when carrying a conversation.

Physical Data Link / Link

In the OSI reference model, these layers are point to point layers.

Physical Data link Network

In the OSI reference model, this layer is an intruder (i.e., it does not belong within this list of options).

Physical ------------- Presentation Session Physical Transport None of the above

For a conversation, these layers may be active on all intermediary devices in the OSI reference model

Physical Data Link Network

This (These) layer(s) are part of the OSI Reference Model.

Physical Data Link Network

In the OSI Reference Model, an L2 switch uses this (these) layer(s) when carrying a conversation.

Physical Data Link / Link

In the OSI Reference Model, a router uses this (these) layer(s) when carrying a conversation.

Physical Data Link / Link Internet / Network

In the OSI Reference Model, your wireless router/access point uses this (these) layer(s) when it is forwarding your streaming traffic.

Physical Internet / Network Data Link / Link

In the OSI Reference Model, your laptop uses this (these) layer(s) when you are browsing the Internet (using an application like Firefox, Chrome, or Internet Explorer).

Physical Application Internet / Network Transport Presentation Data Link / Link Session

For a conversation, these layers (OSI reference model) will be active on all endpoints

Physical Transport Data Link Application Network

In the OSI Reference Model, the youtube server uses this (these) layer(s) when streaming to you videos.

Physical Transport Internet / Network Application Data Link / Link Session Presentation

The MAC sublayer gets service directly from the _______________________. Physical Layer Data Link Layer None of these answers. Network Layer Logical link sublayer

Physical Layer

Check all elements somewhat related to DNS. "Related" means that they interact with, use, are used by, or identify DNS.

Port 53 IP UDP

Check all elements somewhat related to DNS. "Related" means that they interact with, use, are used by, or identify DNS. TCP UDP Port 53 Port 35 IP

Port 53 IP UDP

In the OSI reference model, this layer deals with how different machines map data in memory.

Presentation

In the OSI reference model, these layers are end-to-end layers.

Presentation Session Application Transport

In the OSI reference model, this layer is an intruder (i.e., it does not belong within this list of options).

Presentation ------------------------------------------ None of the above Network Data Link Presentation Physical

In this (these) distributed routing protocol(s), each node communicates ONLY with its immediate neighbors to "learn" about the other nodes on the network.

RIP BGP

Ps/(Tp+(Ps/br)+Tp) Ps/(2Tp+Tr) Ps/(Tp+Tr+Tp)

Suppose that Pure Aloha / slotted is used. Check all frames that will experience a collision. [0.5 1.4 2.5 3.7 4.5]

Pure Frame 0, 1, 3 Slotted Frame (maybe none)

A 1250-byte frame is sent at a bitrate of 10 Mbps over a copper cable 1000 kms long. Recall that a copper cable has a propagation speed about 2/3 the speed of light. Check all right statements

READ CAREFULLY -The propagation time is 5 ms -The total point-to-point (one way) delay is 0.006 s (or 6 ms) -The transmission time is 1,000 -microseconds -The transmission time is 1 ms (There are 2 different questions with 2 different choices. Also there is another version of this question that randomly doesn't have these as the correct answers. I don't know man)

Match each protocol with its original RFC. HTTP 1.1 TCP UDP DNS IP SMTP

RFC 2068 RFC 793 RFC 768 RFC 1034 RFC 791 RFC 821 (May not have all choices)

Check all that apply. The original RFC specifying UDP was _________.

RFC 768

The original RFC specifying UDP was

RFC 768

The original RFC specifying UDP was _______.

RFC 768

The original RFC specifying IP was

RFC 791

The original RFC specifying IP was _____.

RFC 791

The original RFC specifying IP was _________.

RFC 791

The original RFC specifiying TCP was

RFC 793

Transmission lines on WANs are in general made of _______.

Radio links optical fiber copper wire

These Internet pioneers made the Internet stable (free from congestion collapse).

Raj Jain Van Jacobson

Check components that are part of the email architecture presented in class.

Receiver User Agent Sender User Agent

For DNS, the top-level domains are run by __________________ appointed by ICANN.

Registrars

These devices run routing daemons to update routing tables on the Internet.

Routers L3 switches

_________________ is the design issue that consists of finding a path (list of switchs to traverse) between a source host and a destination host.

Routing

Check all concepts/tools/protocols that may be used to modify (update) routing tables. Distance Vector Routing Link State Routing Internet Protocol Routing Information Protocol None of these answers

Routing Information Protocol Distance Vector Routing Link State Routing

This (These) protocol(s) is (are) interior gateway protocol(s) used to update routing tables.

Routing Information Protocol (RIP) Open Shortest Path First (OSPF)

Check the application layer protocol(s) used for the transfer of an email from a Message Transfer Agent to another.

SMTP ESMTP

This (These) protocol(s) are used at the Application layer in the TCP/IP Reference model.

SMTP HTTP RTP DNS (multiple versions - may only have one of these options listed)

The objective is to trace the first FIVE frames that will appear on Segments 1 and 2 as a result of the actions of ONE user. If there are less frames or some field does not apply, fill the cells with N/A. Read carefully the scenario below. Consider this network (Network ID is omitted on the IP addresses): The IP and MAC addresses are on this table: Host Names A B DNS IP Addresses 128.194.45.2/24 128.194.45.187/24 128.194.45.173/24 MAC Addresses Ea Eb Ed We assume that 1) all hosts on this network are running correctly and that Telnet accepts connections on each host. 2) initially, the ARP caches are empty . 3) Bridge cache is initially empty. 3) the user types on Host B the command "Telnet 128.194.45.173".

Seg. 1,2 1 1 1 1 MAC D. 0xFFFFFFFF Eb Ed Eb Ed MAC S. Eb Ed Eb Ed Eb TYPE ARP Request ARP Response IP IP IP IP D. 128.194.45.173 128.194.45.187 128.194.45.173 128.194.45.187 128.194.45.173 IP S. 128.194.45.187 128.194.45.173 128.194.45.187 128.194.45.173 128.194.45.187 Prot # N/A N/A 6 6 6 Port D. N/A N/A None of these answers Port Number Y 23 Port S. N/A N/A Some Port Number Y 53 Port Number Y Flags N/A N/A SYN SYN/ACK ACK

The objective is to trace the first FIVE frames that will appear on Segments 1 and 2 as a result of the actions of ONE user. If there are less frames or some field does not apply, fill the cells with N/A. Read carefully the scenario below. Consider this network (Network ID is omitted on the IP addresses): The IP and MAC addresses are on this table: Host Names A B DNS IP Addresses 128.194.45.2/24 128.194.45.187/24 128.194.45.173/24 MAC Addresses Ea Eb Ed We assume that 1) all hosts on this network are running correctly and that Telnet accepts connections on each host. 2) initially, the ARP cache of each machine is already populated with entries for all the other machines on the same subnet. 3) Bridge cache is initially empty. 3) the user types on Host B the command "Telnet DNS".

Seg. 1,2 1 1 1 1 MAC D. Ed Eb Ed Eb Ed MAC S. Eb Ed Eb Ed Eb TYPE IP IP IP IP IP IP D. 128.194.45.173 128.194.45.187 128.194.45.173 128.194.45.187 128.194.45.173 IP S. 128.194.45.187 128.194.45.173 128.194.45.187 128.194.45.173 128.194.45.187 Prot # 17 17 6 6 6 Port D. 53 Port Number X None of these answers Port Number Y 23 Port S. Some Number X 53 Some Number Y 23 Port Number Y Flags N/A N/A SYN SYN/ACK ACK

The objective is to trace the first FIVE frames that will appear on Segment 2 as a result of the actions of ONE user. If there are less frames or some field does not apply, fill the cells with N/A. Read carefully the scenario below. Consider this network: The IP and MAC addresses are on this table: Host Names A B DNS IP Addresses 128.194.45.110 128.194.45.93 128.194.45.254 MAC Addresses EA EB ED We assume that 1) all hosts on this network are running correctly and that Telnet accepts connections on each host. 2) Initially, the ARP cache of the DNS host is empty while the ARP caches for the rest are as follows Host A 128.194.45.93 EB 128.194.45.254 ED Host B 128.194.45.110 EA 3) The user types on Host B the command "Telnet 128.194.45.254".

Seg. 2 2 2 2 2 MAC D. 0xFFFFFFFF EB ED EB ED MAC S. EB ED EB ED EB TYPE ARP Request ARP Response IP IP IP IP D. 128.194.45.254 128.194.45.93 128.194.45.254 128.194.45.93 128.194.45.254 IP S. 128.194.45.93 128.194.45.254 128.194.45.93 128.194.45.254 128.194.45.93 Prot # N/A N/A 6 6 6 Port D. N/A N/A 23 Some Number X 23 Port S. N/A N/A Some Number X 23 Some Number X Flags N/A N/A SYN SYN/ACK ACK

The objective is to find the number of ARP requests that will appear on Segment 2 as a result of the actions of ONE user. Read carefully the scenario below. Consider this network: segment.png The IP and MAC addresses are on this table: Host Names A B DNS IP Addresses 128.194.45.110 128.194.45.93 128.194.45.254 MAC Addresses EA EB ED We assume that 1) all hosts on this network are running correctly and that Telnet accepts connections on each host. 2) initially, the ARP caches of the Host B and DNS host are empty while the ARP cache for Host A is Host A 128.194.45.93 EB 3) the user types on Host A the command "Telnet 128.194.45.93".

Seg. 2 2 2 2 2 MAC D. EB 0xFFFFFFFF EB EA EB MAC S. EA EB EA EB EA TYPE IP ARP Request ARP Response IP IP IP D. 128.194.45.93 128.194.45.110 128.194.45.93 128.194.45.110 128.194.45.93 IP S. 128.194.45.110 128.194.45.93 128.194.45.110 128.194.45.93 128.194.45.110 Prot # 6 N/A N/A 6 6 Port D. 23 N/A N/A Some Number X 23 Port S. Some Number X N/A N/A 23 Some Number X Flags SYN N/A N/A SYN/ACK ACK

The objective is to find the number of ARP requests that will appear on Segment 2 as a result of the actions of ONE user. Read carefully the scenario below. Consider this network: segment.png The IP and MAC addresses are on this table: Host Names A B DNS IP Addresses 128.194.45.110 128.194.45.93 128.194.45.254 MAC Addresses EA EB ED We assume that 1) all hosts on this network are running correctly and that Telnet accepts connections on each host. 2) Initially, the ARP caches of the Host B and DNS host are empty while the ARP cache for Host A is Host A 128.194.45.93 EB 3) The user types on Host A the command "Telnet B".

Seg. 2 s s s s MAC D. 0xFFFFFFFF EA ED EA EB MAC S. EA ED EA ED EA TYPE ARP Request ARP Response IP IP IP IP D. 128.194.45.254 128.194.45.110 128.194.45.254 128.194.45.110 128.194.45.93 IP S. 128.194.45.110 128.194.45.254 128.194.45.110 128.194.45.254 128.194.45.110 Prot # N/A N/A 17 17 6 Port D. N/A N/A 53 Some Number Y 23 Port S. N/A N/A Some Number Y 53 None of these Answers Flags N/A N/A N/A N/A SYN

Seg. 2,1 1,2 2,1 1,2 2,1 MAC D. 0xFFFFFFFF Ea Eb Ea Eb MAC S. Ea Eb Ea Eb Ea TYPE ARP Request ARP Response IP IP IP IP D. 128.194.45.187 128.194.45.2 128.194.45.187 128.194.45.2 128.194.45.187 IP S. 128.194.45.2 128.194.45.187 128.194.45.2 128.194.45.187 128.194.45.2 Prot # N/A N/A 6 6 6 Port D. N/A N/A None of these answers Port Number Y 23 Port S. N/A N/A Some Number Y 23 Port Number Y Flags N/A N/A SYN SYN/ACK ACK

Seg. 2,1 1,2 2,1 1,2 2,1 MAC D. 0xFFFFFFFF Ea Ed Ea Ed MAC S. Ea Ed Ea Ed Ea TYPE ARP Request ARP Response IP IP IP IP D. 128.194.45.173 128.194.45.2 128.194.45.173 128.194.45.2 128.194.45.173 IP S. 128.194.45.2 128.194.45.173 128.194.45.2 128.194.45.173 128.194.45.2 Prot # N/A N/A 17 17 6 Port D. N/A N/A 53 Port Number Y 23 Port S. N/A N/A Some Number Y 53 Some Port Number X Flags N/A N/A N/A N/A SYN

The objective is to trace the first FIVE frames that will appear on Segments 1 and 2 as a result of the actions of ONE user. If there are less frames or some field does not apply, fill the cells with N/A. Read carefully the scenario below. Consider this network (Network ID is omitted on the IP addresses): The IP and MAC addresses are on this table: Host Names A B DNS IP Addresses 128.194.45.2/24 128.194.45.187/24 128.194.45.173/24 MAC Addresses Ea Eb Ed We assume that 1) all hosts on this network are running correctly and that Telnet accepts connections on each host. 2) initially, the ARP cache of each machine is already populated with entries for all the other machines on the same subnet. 3) Bridge cache is initially empty. 3) the user types on Host A the command "Telnet B"

Seg. 2,1 1,2 2,1 1,2 2,1 MAC D. Ed Ea Eb Ea Eb MAC S. Ea Ed Ea Eb Ea TYPE IP IP IP IP IP IP D. 128.194.45.173 128.194.45.2 128.194.45.187 128.194.45.2 128.194.45.187 IP S. 128.194.45.2 128.194.45.173 128.194.45.2 128.194.45.187 128.194.45.2 Prot # 17 17 6 6 6 Port D. 53 None 23 Port Number Y 23 Port S. Some Number X None of these answers Some Number Y 23 Port Number Y Flags N/A N/A SYN SYN/ACK ACK

Check the action(s) consistent with (i.e., respecting the rules of) the Stop-And-Wait protocol.

Send the same frame after a timeout Send a new frame after receiving an acknowledgement

Any TCP server socket program in Java must use this function call to establish a socket.

ServerSocket

In the OSI reference model, the [name1] layer provides service directly to the presentation layer.

Session

In the OSI reference model, the [name1] layer receives service directly from the transport layer.

Session

In the OSI reference model, this layer is an intruder (i.e., it does not belong within this list of options).

Session ------------------------------------------ Network Session None of the above Physical Data Link

Any TCP client socket program in Java must use this function call to establish a socket.

Socket

Check all statements that apply to the Slotted Aloha protocol

Stations must be clock synchronized, station can send a frame only at the beginning of a slot

______________ is an error control protocol we evaluated in this course.

Stop-And-Wait

Check the main operations performed to send and receive emails.

Submission Transfer Delivery (All options may not be available)

Check the transport layer protocol(s) used for the submission of an email by the Sender User Agent to the Message Transfer Agent.

TCP

Check the transport layer protocol(s) used for the transfer of an email from a Message Transfer Agent to another.

TCP

In the TCP/IP model, FTP uses most of the time this protocol at the transport layer.

TCP

In the TCP/IP model, HTTP uses most of the time this protocol at the transport layer.

TCP

In the TCP/IP model, SMTP uses most of the time this protocol at the transport layer.

TCP

In the TCP/IP model, SSH uses most of the time this protocol at the transport layer.

TCP

The Border Gateway Protocol (BGP) uses _______ as its "transport" protocol.

TCP

______ identifies upper processes (applications) using the port number

TCP

Most hosts on the Internet will have these protocols active on them.

TCP DNS client IP UDP (Not all options may appear)

Match the protocols to their transport protocols they use. BGP OSPF RIP

TCP raw sockets UDP

TCP or UDP port numbers:

TCP and UDP ports are independent from each other

This course will focus on two reference models.

TCP/IP Reference Model OSI Reference Model

Check all that apply. This question explores sharing a channel with capacity of 100 Mbps using a static or a dynamic allocation. The static allocation creates channels with equal capacity of 20 Mbps.

The average delay with static allocation is five times larger than with dynamic allocation With static allocation, there is an upper bound on the delay to deliver a packet. The average delay with static allocation is larger than with dynamic allocation

This question explores sharing a channel with capacity of 100 Mbps using a static or a dynamic allocation. The static allocation creates channels with equal capacity of 20 Mbps. We assume: -The interarrival time of the packets generated by the stations is exponentially distributed (i.e., arrivals form a Poisson process) The size of the packets is exponentially distributed (i.e., the transmission time of a packet is exponentially distributed). Check all true statements. The average delay with static allocation is larger than with dynamic allocation The average delay with static allocation is five times larger than with dynamic allocation None of these answers. With static allocation, there is an upper bound on the delay to deliver a packet. With dynamic allocation, there is an upper bound on the delay to deliver a packet.

The average delay with static allocation is larger than with dynamic allocation With static allocation, there is an upper bound on the delay to deliver a packet. (6.67 / 10 pts)

Check all that apply. This question explores sharing a channel with capacity of 100 Mbps using a static or a dynamic allocation. The static allocation creates channels with equal capacity of 25 Mbps.

The average delay with static allocation is larger than with dynamic allocation With static allocation, there is an upper bound on the delay to deliver a packet. The average delay with static allocation is four times larger than with dynamic allocation

TCP stands for

Transmission Control Protocol

______________ provides service directly to ______________

The medium access control sublayer logical link sublayer

__________ provides service directly to __________ .

The medium access control sublayer the logical link sublayer

Check which action(s)/effect(s), if removed, would eliminate distorsion. Check the smallest number of actions/effects to remove in order to eliminate distorsion.

The medium is unfair to signals with different frequencies

Check all weaknesses of static allocation of a broadcast channel with capacity C assuming there are n stations with n ≥ 2. Messages from different stations may collide on one channel. The number of available channels cannot be easily decreased. Each channel may be over used. None of these answers. The number of available channels cannot be easily increased.

The number of available channels cannot be easily decreased. The number of available channels cannot be easily increased.

Check all true statements about the physical layer in the context of the OSI reference model.

The physical layer offers service directly to the data link layer The physical layer will carry all the messages exchanged peer to peer by all the layers.

A 1250-byte frame is sent at a bitrate of 10 Mbps over a copper cable 1000 kms long. Recall that a copper cable has a propagation speed about 2/3 the speed of light. Check all right statements The total point-to-point (one way) delay is 0.006 s The propagation time is about 3.34 ms None of these choices The propagation time is 5 ms The transmission time is 1 s The transmission time is 1,000 microseconds The propagation time is 0.01 s The transmission time is 1 ms None of these choices The propagation time is 10 ms

The total point-to-point (one way) delay is 0.006 s The total point-to-point (one way) delay is 6 ms The propagation time is 5 ms The transmission time is 1 ms (There is 1 more answer, probably The transmission time is 1,000 microseconds)

TCP or UDP port numbers:

They range from 0 to 65535

Throughput/bit rate by definition

Tp + Ct + Tp 2Tp + Ct

This question is related to the performance evaluation of the Stop-And-Wait protocol on an error-free channel. Refer to the figure to answer. Within the same cycle, the variable T is equal to ________________ assuming that we neglect the time to process a received packet. T p + T r + T a + T pT p + T r + T a + T p T r + C t + T a + 2 T pT r + C t + T a + 2 T p None of these answers 2 T r + T a + T p2 T r + T a + T p 2 T p + T r + T a2 T p + T r + T a 2 T p + T r + C t + T a2 T p + T r + C t + T a

Tp + Tr + Ta + Tp 2Tp + Tr + Ta

In the OSI reference model, TCP belongs to the _____layer.

Transport

In the OSI reference model, the [name1] layer provides service directly to the session layer.

Transport

In the OSI reference model, the [name1] layer receives service directly from the network layer.

Transport

In the OSI reference model, this end-to-end layer deals with addressing and congestion control (besides other functions).

Transport

In the OSI reference model, this end-to-end layer deals with error control and flow control (besides other functions).

Transport

In the OSI reference model, this layer is the lowest end to end layer (closest to the physical layer).

Transport

The TCP protocol may be provided by this (these) layer(s) in the OSI reference model Network None of these answers Physical Transport Data Link Session Presentation Application

Transport

The UDP protocol may be provided by this (these) layer(s) in the OSI Reference model.

Transport

In the TCP/IP Reference Model, your laptop uses this (these) layer(s) when you are browsing the Internet (using an application like Firefox, Chrome, or Internet Explorer).

Transport Application Link Internet/Network

The OSI Reference Model includes this (these) layer(s).

Transport Data Link Presentation

Error control is in general provided by this (these) layer(s) in the OSI Reference model.

Transport Data link

The TCP/IP Reference Model includes these layers.

Transport Internet Link Application (multiple versions - may only have one of these options listed)

In the TCP/IP Reference Model, the youtube server uses this (these) layer(s) when streaming to you videos. Transport None of these answers Session Internet/Network Link Application Presentation

Transport Internet/Network Link Application

In the TCP/IP Reference Model, your laptop uses this (these) layer(s) when you are configuring your wireless router/access point using a browser. Application Session Link Presentation Transport Internet/Network None of these answers

Transport Internet/Network Link Application

The OSI Reference Model includes this (these) layer(s).

Transport Physical Application

The OSI Reference Model includes this (these) layer(s).

Transport Session Network

In the TCP/IP Reference Model, your laptop uses this (these) layer(s) when you are configuring your wireless router/access point using a browser. Session None of these answers Transport Application Internet/Network Link Presentation

Transport Application Internet/Network Link

Routing protocols such as RIP, OSPF or BGP periodically update the routing tables.

True

Routing protocols such as RIP, OSPF or BGP periodically update the routing tables.

True DELETE

On an Ethernet frame, the ________ field indicates whether the frame carries an IP, an ARP, or a RARP packet/

Type

A DNS client uses ________ at the transport layer.

UDP

A DNS server uses ________ at the transport layer.

UDP

In the TCP/IP model, DNS uses most of the time this protocol at the transport layer.

UDP

The Routing Information Protocol (RIP) uses _______ as its "transport" protocol.

UDP

______ uses a checksum to detect corrupted datagrams

UDP

_______ identifies upper processes (applications) using the port number

UDP

_______ offers a minimal service to the application layer

UDP

Check the protocol(s) that belong(s) to the transport layer

UDP TCP

This (These) protocol(s) are used at the Transport layer in the TCP/IP Reference model.

UDP TCP (there are multiple versions so there may only be one of these in the list of options)

Match these protocols in the TCP/IP reference model to the (transport) port number they use. Choose "N/A" if the protocol does not use a port number.

UDP -- N/A IMAP -- 143 TCP -- N/A HTTP -- 80 DNS -- 53 Telnet -- 23 IP -- N/A TFTP -- 69 SMTP -- 25 FTP -- 21 ssh -- 22 (May not have all listed)

Match protocols to their original RFCs.

UDP RFC 768 TCP RFC 793 IP RFC 791 ICMP RFC 792

____________ is a popular wireless MAN protocol.

WiMax

This question explores sharing a channel with capacity of 100 Mbps using a static or a dynamic allocation. The static allocation creates channels with equal capacity of 25 Mbps. We assume: -The interarrival time of the packets generated by the stations is exponentially distributed (i.e., arrivals form a Poisson process) The size of the packets is exponentially distributed (i.e., the transmission time of a packet is exponentially distributed). Check all true statements. None of these answers. With static allocation, there is an upper bound on the delay to deliver a packet. With dynamic allocation, there is an upper bound on the delay to deliver a packet. The average delay with static allocation is four times larger than with dynamic allocation The average delay with static allocation is larger than with dynamic allocation

With static allocation, there is an upper bound on the delay to deliver a packet. The average delay with static allocation is four times larger than with dynamic allocation The average delay with static allocation is larger than with dynamic allocation

A receiver receives the following frame using Flag Bytes with Byte Stuffing: FLAG Y X ESC FLAG R FLAG where letters A-Z represent bytes. The payload, i.e., the message, sent (without the stuffing if any) inside this frame is _________.

Y X FLAG R

This word, sent using odd parity, is received. Word = 1011 1011 0 Was the word corrupted?

Yes

Check all that apply. The function call ServerSocket is used by_________________. - a Java TCP server to exchange data with a client -None of these answers -a Java TCP Client -a Java TCP Server to establish a TCP server -any socket client

a Java TCP Server to establish a TCP server

ARP returns as output ___________________.

a MAC address

Check all that apply. This question is related to the performance evaluation of the Stop-And-Wait protocol on an error-free channel. Refer to the figure to answer. Within the same cycle, the variable T is equal to the duration between when ________________.

a cycle ends and when it starts the last bit of the ack is received and when the first bit of the packet is sent

An IP address indentifies

a network identifies

An IP address identifies

a network interface

TCP is

a peer-to-peer communication protocol

Rules governing peer-to-peer communications are called _____________.

a protocol

Check all statements that apply to the Slotted Aloha protocol. a station can send a frame only at the beginning of a slot achieves maximal channel utilization of about 37% for any traffic (i.e., arrivals follow any probability distribution). a station sends a frame after sensing the medium idle stations must be clock synchronized None of these answers

a station can send a frame only at the beginning of a slot stations must be clock synchronized

The presentation layer provides this (these) service(s).

allows machines with different data representations to communicate.

Check all statements/method calls that TCP server or client must absolutely include to receive data using I/O streams a and b. The TCP server or client uses the socket variable sock. -None of these answers -a.read(......) -InputStream a = sock.getInputStream(); -OutputStream b = sock.getOutputStream(); -a.write(...)

a.read(....) InputStream a = sock.getInputStream();

Check all statements/method calls that TCP server or client must absolutely include to receive data using I/O streams a and b. The TCP server or client uses the socket variable sock. None of these answers a.read(......) InputStream a = sock.getInputStream(); OutputStream b = sock.getOutputStream(); a.write(...)

a.read(.....) InputStream a = sock.getInputStream();

Match each quantity Q to its expression (i.e., to compute Q). The table describes the notation used: NameDescriptionaDistance between Sender and ReceiverbPropagation SpeedcBit RatedFrame/Packet SizeeTransmission TimefPropagation Time Propagation Time a/b Transmission Time d/c Bit Rate d/e Propagation Speed

a/b d/c d/e a/f

The purpose of each layer is to offer services to the layer just ________ it.

above

Consider a sender and a receiver connected using a "lossy" (loss-prone) channel. Check all required countermeasures at the receiver to insure reliable communications.

ack for well received packets

Consider a sender and a receiver connected using a noisy (corruption-prone) channel. Assuming that the sender retransmit corrupted packet, check all required countermeasures to insure reliable communications. ack for well received packets None of these answers. error correction retransmission timeout error detection

ack for well received packets error detection

Check all that applies to TCP:

adapts to slow receiver's speed provides a reliable in order delivery system adapts to network congestion adapts to slowest intermediary node speed

In the context of computer networks, ARP stands for _________________.

address resolution protocol

_________ is the design issue that consists of identifying the senders and receivers.

addressing

The data link layer offers in general these services/functions.

addressing error control flow control medium access control

These functions services are offered by the network layer.

addressing routing

Check the functions/services offered by the data link layer.

addressing medium access control error control framing flow control

The network layer offers these services/functions.

addressing/naming routing congestion control

An interface defines the primitive operations and services between _________ layers.

adjacent

Assuming two or more stations, check all media/topologies that require medium access control.

air wireless medium A coaxial cable on which multiple stations can send. Vacuum Point-to-point half-duplex channel

ARP takes as input ___________________.

an IP address

The rules governing the request/delivery of a service between adjacent layers is called _______________.

an interface

A medium impacts a signal it carries in different ways. In general, a coaxial cable __________ a signal that is a pure sine (cosine) wave (i.e., a signal using one frequency only).

attenuates delays

A medium impacts a signal it carries in different ways. In general, a twisted pair cable __________ a signal that is a pure sine (cosine) wave (i.e., a signal using one frequency only).

attenuates delays

A medium impacts a signal it carries in different ways. In general, a medium __________ a signal that is a baseband signal.

attenuates delays distorts

A medium impacts a signal it carries in different ways. In general, a coaxial cable __________ a signal that is a baseband signal.

attenuates distorts delays

Complete the words starting with the indicated first letter. Do not repeat the first letter. The physical layer deals with transporting r__________ b___________

aw; its

Each layer requests service(s) from the layer just ________ it.

below

Let us use the following notation: - P s is the packet size (number of bits in P) - b e r be the bit error rate. - p e r is the packet error rate The probability that a bit gets corrupted is _________.

ber

The transmission time depends on the ______________.

bit rate frame size

The transmission time depends on the ______________. None of these answers distance between the sender and the receiver bit rate transmission medium frame size propagation speed

bit rate frame size

Check all factors that impact the queueing time to send a packet from the sender to a receiver. transmission system used to put bits on the medium. None of these answers kind of medium the rate of traffic generated by the upper layers distance between the sender and the receiver bit rate

bit rate the rate of traffic generated by the upper layers transmission system used to put bits on the medium

Check all factors that impact the transmission time to send a packet from the sender to a receiver.

bit rate transmission system used to put bits on the medium.

Consider this variable: byte flags; The expression ((flags & 4) == 4) is of type ____________.

boolean

On a ______________ medium, frames (packets) sent by any machine on that medium are received (heard) by all other machines on the medium.

broadcast

Wireless local area networks (LANs) often use ___________________ channel(s).

broadcast

Consider this code snapshot: int a, e; short b, f; byte g; DataOutputStream c; DataInputStream d; ByteArrayOutStream x = new ByteArrayOutputStream(); c = new DataOutputStream(x); Select the most likely valid statement to encode data to be sent out using TCP or UDP sockets

c.writeByte(g)

c.writeInt(a)

c.writeShort(b)

In the CSMA/CD acronym, CD stands for ________________.

collision detection

The application layer provides this (these) service(s).

communicates with the end user. allows the end users to use the network services.

In the TCP/IP Reference Model, your Bluetooth interface uses this (these) layer(s) when you are browsing the Internet.

data Link / Link

In the OSI Reference Model (computer networks), the MAC is a sublayer of the ________________ layer

data link

In the OSI reference model, the [name1] layer provides service directly to the network layer.

data link

In the OSI reference model, the [name1] layer receives service directly from the physical layer.

data link

In the OSI reference model, this layer provides service directly to the network layer.

data link

Fill in the blanks. Some words are hinted by the first letter. Do not repeat the first letter. The ______ layer provides service directly to the network layer and has two sublayers: L _____ and M _____

data link ogical link layer edium access control

The ________ layer provides service directly to the network layer and has two sublayers: L________ and M___________

data link ogical link layer edium access control

When implementing a connectionless service, we use ___________________ to carry messages.

datagrams

A medium impacts a signal it carries in different ways. In general, an optical fiber __________ a signal that is a pure sine (cosine) wave (i.e., a signal using one frequency only).

delays attenuates

A medium impacts a signal it carries in different ways. In general, an optical fiber __________ a signal that is a baseband signal.

delays attenuates distorts

Suppose that a function f(x) reaches its maximal value for some value LaTeX: x_{\max} If LaTeX: x_{\max} exists then LaTeX: x_{\max} is the solution of the equation _____________

df(x)/dx (Xmax)=0

Check all factors that impact the propagation time to send a packet from the sender to a receiver. bit rate the rate of traffic generated by the upper layers None of these answers kind of medium distance between the sender and the receiver transmission system used to put bits on the medium.

distance between the sender and the receiver kind of medium

The propagation time depends on the ______________.

distance between the sender and the receiver propagation speed transmission medium

Check all that apply. Any medium impacts a signal it carries in different ways. In general, a medium __________ a signal that is a mix (sum) a signals using different frequencies. None of these answers delays separates amplifies distorts attenuates

distorts attenuates delays

DNS stands for _____ _____ _____ .

domain name system

This question is about CSMA schemes. When a collision between two or more frames occurs, each station will _____________.

drop all damaged frames even if only one bit is damaged in each.

In the context of computer networks, DHCP stands for _________________.

dynamic host configuration protocol

e = v.readInt()

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". We defined the probability P 0as having no collisions. We derived that P 0 =___________. None of these answers e − 2. G e 0 e − G 1 − G

e − 2. G

In order to evaluate the Slotted Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". We defined the probability P 0as having no collisions. We derived that P 0 =___________.

e − G

Check all that apply to IEEE 802.3 (Ethernet)

has a contention-based MA protocol has in general a lower average time delivery than Token-ring

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". We defined the probability P 0as having no collisions. We derived that P 0 =___________.

e^ (-2G)

In order to evaluate the Pure Aloha protocol, We defined the probability P_0 as having no collisions. We derived that P_0= _________

e^-2G

In order to evaluate the Slotted Aloha protocol. We defined the probability P_0 as having no collisions. We derived that P_0 = ___________.

e^-G

The transport layer offers in general these services/functions.

error control congestion control addressing/naming flow control

________________ consists of correcting errors in the received information.

error correction

Error control consists of __________________ and ___________________. None of these answers. error control error correction packet loss error corruption

error correction error detection

_________ ________ is the design issue that consists of finding errors in the received information.

error detection

Consider a sender and a receiver connected using a noisy (corruption-prone) channel. Assuming that the sender retransmit corrupted packets, check all required countermeasures at the receiver to insure reliable communications.

error detection ack for well received packets

Consider a sender and a receiver connected using a real life channel. Assuming that the sender retransmits corrupted packets, check all required countermeasures to insure reliable communications

error detection retransmission timeout ack for well received packets

A user types the command "arp -a" on the console of the machine csexmac161engauburnedu. The arp command displays (see picture) the content of the ARP cache of the machine csexmac161engauburnedu. Suppose that IP on this machine must send a packet to the interface with IP Address 192.168.1.114. When IP asks ARP for the address 192.168.1.114, ARP will return the MAC address ________________.

f4:5c:89:b6:b8:e7

Routing protocols such as IP, RIP, OSPF or BGP periodically update the routing tables.

false

Using Pure Aloha, a station must sense the medium before transmitting.

false

Using Slotted Aloha, a station can transmit any time a frame is ready.

false

female rich

The network layer provides this (these) service(s).

finds paths between senders and receivers. may handle congestion.

Match each data transfer unit to its layer or protocol (Data) Link Layer Network (Internet) Layer TCP UDP

frame packet segment datagram

Consider the table below that provides the time t R a frame is ready to be sent at a station. t Ris provided using as unit the transmission time T rof a frame. The first line provides the frame #. The second line provides the time t Rfor each frame. Frame #01234t R(in T r)0.51.42.53.74.5 Suppose that Pure Aloha is used. Check all frames that will experience a collision. Frame # 1 Frame # 0 Frame # 3 None of these answers Frame # 2

frame 0, 1, and 3

Consider the table below that provides the time t R a frame is ready to be sent at a station. t Ris provided using as unit the transmission time T rof a frame. The first line provides the frame #. The second line provides the time t Rfor each frame. Frame #01234t R(in T r)01.11.992.24.3 Suppose that Slotted Aloha is used. Check all frames that will experience a collision. Frame # 2 Frame # 0 None of these answers Frame # 1 Frame # 3

frame 1 and 2

Check the functions/services offered by the logical link layer.

framing flow control addressing error control

Local radio stations use in general ______________ division multiplexing to share the medium (air).

frequency

The GSM (Global System for Mobile applications) uses ____________ division multiplexing.

frequency time

Collision-free (i.e., with dedicated channels) multiple access protocols ____________.

guarantee upper bounds on delivery time

Select one. Collision-free (i.e., with dedicated channels) multiple access protocols ____________. are not used on wireless networks have a better average delivery time than contention based MA protocols. work well for wide-area networks (>2,000 km) None of these answers guarantee upper bounds on delivery time

guarantee upper bounds on delivery time

A routing table is similar to a(n) _______________ for a road trip.

guiding (directions) sign at an intersection

The transport layer provides this (these) service(s).

handles congestion detects transmission errors splits messages too large for the network

On networks, the machines that run users programs (applications) are most likely called ________.

hosts

Check all conditions for a packet P to be received correctly

if it does not get lost if no bit in P is corrrupted

A packet P will not get corrupted if no bit in P is corrrupted None of these answers. if at most two bits in P get corrupted if at most one bit in P gets corrupted if it does not get lost

if no bit in P is corrrupted

A packet P will get corrupted ___________________________

if only one bit in P gets corrupted

This question is related to error detection. Increasing the number of check bits to the payload ('message' to send) will ______________.

increase the overhead decrease the probability to misdiagnose a corrupted.

This question is related to error detection. Decreasing the number of check bits to the payload ('message' to send) will ______________.

increase the probability to misdiagnose a corrupted. decrease the overhead

A network is a set of ___________ devices which can communicate.

independent

Based on Shannon's Theorem, the capacity of a noiseless channel is ________. infinite less than 1 Gbps. None of these answers null lower than Nyquit's limit with a valence of 2

infinite

Consider the method DatagramPacket(a, b, c, d). The type of the parameter b is _____________ assuming that d is a port number.

int

Consider the method DatagramPacket(a, b, c, d). The type of the parameter d is _____________ assuming that d is a port number.

int

Consider this variable: byte flags; The expression (flags & 4) is of type ____________.

int

A(n) __________ is a set of rules defining communications between adjacent layers.

interface

In the context of computer networks, ICMP stands for _________________.

internet control message protocol

Select the best answer. A garment that is made with only one kind of fabric is like a signal that __________________. cannot be attenuated cannot be delayed None of these answers is a pure sine or cosine (periodical signal with one frequency) is a periodical signal with multiple frequencies

is a pure sine or cosine (periodical signal with one frequency)

The call ServerSocket in Java performs these actions:

it binds to a port it creates a socket it may adjust the incoming queue

j . C + ( j − 1 ) . P

Fill in the words starting with the letters indicated: do not repeat the first letter(s). The physical layer deals with the E___________ and M___________ specifications.

lectrical; echanical

To reduce their design complexity, most networks architectures are organized as ___________.

levels, stacks, layers

When a sender sends a packet P that gets reordered, a receiver _______________.

may receive before Packet P a packet Q sent after Packet P was sent.

In computer networks, MAC stands for

medium access control

This service does not belong to the logical link layer.

medium access control

mer

Broadcast channels are also referred to as ___________ channels.

multiaccess random access

Based on the textbook, broadcast channels are sometimes referred to as ___________________________ .

multiaccess channels random access channels

On a ______________ network, frames (packets) sent by any machine on that link are received (heard) by a subset of machines.

multicast

A header is a message exchange between Layer n and Layer ________.

Two key functions/services offered by the network layer are R___________ and A___________. Do not repeat the first letter(s).

outing; ddressing

In the OSI reference model, IP (Internet Protocol) belongs to the _________ layer.

network

In the OSI reference model, an instance in the transport layer wants to send a data unit m. The first header added to m will be a header belonging to the ________ layer.

network

A set of layers and protocols is called a _______ __________.

network architecture

Consider a sender and a receiver connected using an ideal (error-free) channel. Assuming that the sender does not retransmit, check all required countermeasures to insure reliable communications

none of these answers

Consider the table below that provides the time t R a frame is ready to be sent at a station. t Ris provided using as unit the transmission time T rof a frame. The first line provides the frame #. The second line provides the time t Rfor each frame. Frame #01234t R(in T r)0.51.63.84.95.3 Suppose that Slotted Aloha is used. Check all frames that will experience a collision. Frame # 0 Frame # 2 Frame # 3 Frame # 1 None of these answers

none of these answers

Consider the table below that provides the time t R a frame is ready to be sent at a station. t Ris provided using as unit the transmission time T rof a frame. The first line provides the frame #. The second line provides the time t Rfor each frame. Frame #01234t R(in T r)01.12.13.24.1 Suppose that Slotted Aloha is used. Check all frames that will experience a collision. Frame # 0 Frame # 3 Frame # 1 None of these answers Frame # 2

none of these answers

Consider the table below that provides the time t T a frame transmitted at a station. t Tis provided using as unit the transmission time T rof a frame. The first line provides the frame #. The second line provides the time t T for each frame. Frame #01234t T(in T r)1.23.674.156.538 Check all frames that were sent by stations that do not comply to the Pure Aloha protocol. None of these answers Frame # 1 Frame # 3 Frame # 2 Frame # 0

none of these answers

Consider the table below that provides the time t T a frame transmitted at a station. t Tis provided using as unit the transmission time T rof a frame. The first line provides the frame #. The second line provides the time t T for each frame. Frame #01234t T(in T r)1.534.46.18 Check all frames that were sent by stations that do not comply to the Pure Aloha protocol. None of these answers Frame # 3 Frame # 2 Frame # 0 Frame # 1

none of these answers

In the TCP/IP reference model, an instance in the internet layer wants to send a data unit m. The first header added to m will be a header belonging to the ________ layer.

none of these answers

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". Assume that the generated traffic is Poisson (G = 0.25) and that we are using the transmission time T r as unit. The probability that 0 frame are generated during 0.5 unit time is ______________. Help:

not 0.77

In order to evaluate the Pure Aloha protocol, we defined Nas the number of new frames (on all stations) to be transmitted per "frame time". "frame time" was defined as the time to transmit one frame (transmission time, as we neglect the propagation time). We also defined G as the number of generated frames (on all stations) to be transmitted per "frame time". We established that the throughput S (G . e − 2 G) for Pure Aloha is maximal for the value ___________. G = 1 None of these answers G = 0 G = 0.5 G = 0.18

not G = 0.18

This question explores the time to send and acknowledge a frame when using retransmission on a noisy (error-prone) channel. We assume that: 1) it takes Time C to send a frame (C=T(m+n) as defined on the slides)2) there is a penalty P when a (re)transmission fails.3) the packet error rate is per. It takes time ________________ to send a frame and get a positive acknowledgement if the first transmission is successful. C . ( 1 − p e r )C . ( 1 − p e r ) CC None of these answers. BB 2. C + P

not none of these answers

Check all metrics that are similar to throughput as defined in this course. None of these answers number of processes completed per second by a CPU number of printed pages per minute by a printer CPU busy time number of copied pages per minute by a photocopier CPU utilization percentage/fraction

number of processes completed per second by a CPU number of printed pages per minute by a printer number of copied pages per minute by a photocopier

This question explores the time to send and acknowledge a frame when using retransmission on a noisy (error-prone) channel. We assume that: 1) it takes Time C to send a frame (C=T(m+n) as defined on the slides)2) there is a penalty P when a (re)transmission fails.3) the packet error rate is per. The probability to send a frame and get a positive acknowledgement only after the 2nd transmission is __________________

p e r . ( 1 − p e r )

This question explores the time to send and acknowledge a frame when using retransmission on a noisy (error-prone) channel. We assume that: 1) it takes Time C to send a frame (C=T(m+n) as defined on the slides)2) there is a penalty P when a (re)transmission fails.3) the packet error rate is per. The probability to send a frame and get a positive acknowledgement only after the 4th transmission is __________________

p e r 3 . ( 1 − p e r )

This question explores the time to send and acknowledge a frame when using retransmission on a noisy (error-prone) channel. We assume that: 1) it takes Time C to send a frame (C=T(m+n) as defined on the slides)2) there is a penalty P when a (re)transmission fails.3) the packet error rate is per. The probability to send a frame and get a positive acknowledgement only after the jth transmission is __________________

p e r j − 1 . ( 1 − p e r )

A protocol defines the communications rules between _________ layers.

peer

Layers at the same level on two communicating machines are called _________ .

peer layers

Evaluating a networking protocol consists of assessing its ____________________. performance None of these answers simulation implementation correctness

performance correctness

PSK stands for

phase shift keying

In the OSI reference model, the [name1] layer provides service directly to the data link layer.

physical

Wide area networks (WANs) often use ___________________ channel(s).

point-to-point

UDP and TCP identifies upper process using the

port number

UDP identifies upper processes (applications) using the ___.

port number

In the OSI reference model, an instance in the application layer wants to send a data unit m. The first header added to m will be a header belonging to the ________ layer.

presentation

In the OSI reference model, socket programming functions like ntohs(), htons(), ntohl(), or htonl() belong logically to the [name1] layer

presentation

In the OSI reference model, socket programming functions like ntohs(), htons(), ntohl(), or htonl() belong logically to the _____ layer.

presentation

In the OSI reference model, the [name1] layer provides service directly to the application layer.

presentation

In the OSI reference model, the [name1] layer receives service directly from the session layer.

presentation

The delay for a frame from sender to receiver depends on the ______________. propagation speed transmission medium distance between the sender and the receiver None of these answers bit rate frame size

propagation speed transmission medium frame size bit rate distance between sender and receiver

A(n) __________ is a set of rules defining communications between peer layers.

protocol

Peer layers use a [name1] to communicate.

protocol

A list of the protocols used by certain system, one protocol per layer, is called a _______ __________.

protocol stack

The Internet is a _______ switching system.

store-and-forward packet

Any periodic signal can be constructed as the [name1] of a number of cosine and sine waves of different frequencies.

sum

___ connect two or more ___

switches transmission lines

the last bit of the ack is received and when its first bit is received the last bit or the ack is put on the medium and when its first bit is put on the medium

This question is related to the performance evaluation of the Stop-And-Wait protocol on an error-free channel. Refer to the figure to answer. Within the same cycle, the expression T p + T a is equal to the duration between when ________________.

the last bit of the ack is received and when its first bit is sent (None of these answers if the above option isn't present)

the last bit of the packet is received and when its first bit is received the last bit of the packet is put on the medium and when its first bit is put on the medium NOT the last bit of the packet is received and when its last bit is sent the last bit of the packet is received and when its first bit is sent the first bit of the packet is received and when its first bit is sent

This question is related to the performance evaluation of the Stop-And-Wait protocol on an error-free channel. Refer to the figure to answer. Within the same cycle, the expression T p + T r is equal to the duration between when ________________.

the last bit of the packet is received and when its first bit is sent NOT the first bit of the packet is received and when its first bit is sent AND the last bit of the packet is received and when its last bit is sent NOT the last bit of the ack is received and when its first bit is sent

The propagation time depends on the ______________.

transmission medium propagation speed distance between the sender and the receiver

Check all factors that impact the total time to send a packet from the sender to a receiver.

transmission system used to put bits on the medium. the rate of traffic generated by the upper layers distance between the sender and the receiver kind of medium bit rate

This question is related to the performance evaluation of the Stop-And-Wait protocol on an error-free channel. Refer to the figure to answer. Within the same cycle, the variable T p is equal to the duration between when ________________. (there are 2 sets of answers to this question) the first bit of the packet is received and when its first bit is sent the last bit of the packet is put on the medium and when its first bit is put on the medium the last bit of the packet is received and when its last bit is sent the last bit of the packet is received and when its first bit is sent the last bit of the packet is received and when its first bit is received.

the last bit of the packet is received and when its last bit is put on the medium the first bit of the packet is received and when its first bit is put on the medium the last bit of the ack is received and when its last bit is put on the medium the first bit of the ack is received and when its fist bit is put on the medium the last bit of the packet is received and when its last bit is sent. the first bit of the packet is received and when its first bit is sent. the first bit of the ack is received and when its first bit is sent the last bit of the ack is recieved and when its last bit is sent

A medium attenuates a signal means that ______________.

the signal strength (amplitude) decreases as the signal travels further.

TCP or UDP port numbers:

they are 16 bit numbers

Congress representatives (when well behaving) use ____________ division multiplexing to participate in the debate.

time

Consider a sender and a receiver connected using a "lossy" (loss-prone) channel. Check all required countermeasures to insure reliable communications.

timeout ack for well received packets restransmission

Consider a sender and a receiver connected using a "lossy" (loss-prone) channel. Check all required countermeasures at the sender to insure reliable communications.

timeout retransmission

The word 1001 0111 is received using the Hamming code C. The original word that was most likely sent originally (before corruption) was _____________. Code C uses four codewords L, M, N, and O defined as follows: Code C: L : 0000 0000 M: 0100 1011 N: 1011 0101 O: 1111 1010

undetermined

Point-to-point transmission with exactly one sender and exactly one receiver is sometimes called ___________.

unicasting

When a sender sends a packet P that gets lost, a receiver _______________.

will not receive any packet

When a sender sends a packet P that gets corrupted, a receiver _______________.

will receive a packet P' different from Packet P

Consider a system with 4 stations X,Y, Z, and W that use CDMA. These four stations use the chip sequences x, y, z and w that are all mutually orthogonal. Stations X, Y, Z, and W send 1, 1, 0, and 1, respectively. The resulting signal S on the medium is equal to ______.

x + y - z + w

||z||^2

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