Networks Final

Select the form of media access control that Ethernet uses. -Carrier Sense Multiple Access Collision Avoidance -Carrier Sense Multiple Access/Collision Detection -Carrier Sense Multiple Access/Collision Acknowledge -Carrier Sense Multiple Access/Collision Delay -None of the other answers are correct.

-Carrier Sense Multiple Access/Collision Detection

Improving circuit capacity on a backbone network is one way to increase the network's performance. -True -False

-True

What technology, under ideal conditions, will provide data rates up to 70 Mbps for up to 30 miles? -WiMax -802.11n -802.11g -WiFi

-WiMax

IPv4 Network Layer addresses are how many bits long?

32 Bits

The two basic types of media are:

guided and wireless (radiated)

TCP has a nominal 20 byte header for all PDUs. Some protocols have a separate type of PDU that carry no data for sending acknowledgments and flow control. Imagine that a new version of TCP utilized these seperate acknowledgment and flow control PDUs. How many bytes could be removed from the existing TCP header for the standard TCP PDU? 2 4 8 6

6

_____________ is an effective way to prevent impulse noise, cross talk, and intermodulation noise. Shielding wires Shorting a circuit Adding fluorescent lights Adding repeaters to a circuit

Shielding Wires

Networks have been based on two models; the layered model and the method a. beads-on-a-string b. neural net c. bell-head d. wired

a. beads on a string

When a network protocol utilizes Automatic Repeat Request (ARQ), a NAK: a. means that the sender should continue with sending the next message b. is sent by the recipient if the message contains an error c. refers to non-asynchronous Kermit technique d. is sent by the sender at the same time as it sends a data packet e. is sent by the recipient if the message was received without error

b. is sent by the recipient if the message contains an error

IMAP (Internet Message Access Protocol)

permits an email message to remain stored on the mail server even after they have been read by a client computer

Most Countries, permit WLANs to operate in two frequency ranges that have been reserved for unlicensed transmissions those are -1GHz range and the 4GHz range -4GHz range and the 5GHz range -the 2.4GHz range and the 5GHz range -the 3GHz range and the 4GHz range -6GHz range and the 7GHz range

the 2.4GHz range and the 5GHz range

The most commonly used e-mail standard is:

SMTP (Simple Mail Transfer Protocol)

Select all statements that are correct in the context of a a wide-area network (WAN). -Adding a packet-switched service that is used only when demand exceeds circuit capacity is one way to improve performance on a WAN. -Upgrading the capacity of circuits on a WAN always results in better network performance. -If the use of a specific circuit is approaching its capacity on a WAN, the best way to improve network performance is always to upgrade that circuit's capacity. -Circuits on a WAN that are not used to capacity can usually be downgraded to save on cost.

-Adding a packet-switched service that is used only when demand exceeds circuit capacity is one way to improve performance on a WAN. -Circuits on a WAN that are not used to capacity can usually be downgraded to save on cost.

Select all alternatives that correctly describe broadcast messages. -The majority of broadcast messages usually occur at the transport layer -Broadcast messages usually consume more network resources on switched backbones than on routed backbones. -Broadcast messages can place a lot of demand on backbone networks. -The majority of broadcast messages usually occur at the network layer -The majority of broadcast messages usually occur at the data link layer.

-Broadcast messages usually consume more network resources on switched backbones than on routed backbones. -Broadcast messages can place a lot of demand on backbone networks. -The majority of broadcast messages usually occur at the data link layer.

In the context of a virtual private network, a tunnel can most accurately be described as _________________________. -a virtual circuit through a LAN. -a virtual circuit through the Internet. -a SSH connection between the sender and the receiver. -a connection between the sender and the receiver. -a virtual circuit that spans exactly two networks.

-a virtual circuit through the Internet.

The highest layer most switches operate at is the __________ layer. -physical -application -data link -network -transport

-data link

Switched backbone architectures use a(n) _____________ topology. -linear -inverted -star -ad-hoc

-star

Switched Ethernet: -has a logical topology of a bus -uses a hub to connect computers -has a physical topology of a ring -has a logical topology of a ring -usually enables all attached circuits to send or receive packets simultaneously

-usually enables all attached circuits to send or receive packets simultaneously

What is the maximum cable segment length for 10Base-T when using 100 Ohm unshielded Twisted Pair cable? 100 meters 125 meters 75 meters 150 meters 25 meters

100 meters

Which security system changes the key for every frame it transmits to the client. 802.11i WEP WPA VPN SSID

WPA

When sending seven bits at at time using frequency modulation, the number of different frequency levels that would be needed would be a. 128 b. 14 c. 64 d. 7 e. 2

a. 128 --> 2^7

For a transport protocol to be reliable, it must meet specific requirements. From the alternatives below, select all that are requirements of a reliable transport protocol. a. duplication control b. loss control c. fragmentation d. transmission errors control e. packetizing

a. duplication control b. loss control d. transmission errors control

How many bits per sample are required to sample an incoming signal 8000 times per second using 32 different amplitude levels? a. 4 b. 5 c. 256,000 d. 8,000 e. 10 f. 32 g. None of the above

b. 5

If each sample uses 8 bits and the number of samples taken each second is 4000; then the transmission speed on the circuit is? a. 500 bps b. None c. 8000 bps d. 500 kbps e. 16 Kbps

b. Nond

Optical Media__________. a. has the same likelihood of suffering from noise as coaxial cable b. is more prone to noise than twisted pair media c. is less likely to suffer from noise than electrical media d. is more likely to suffer from noise than electrical media e. has about the same likelihood of suffering from noise as electrical media

c. is less likely to suffer from noise than electrical media

Which of the following is not true about ITU-T? a. It is based in Geneva b. It is the international Telecommunications Union - Telecommunications Group c. Its membership is limited to US telephone companies d.Its membership is comprised of representatives from over 200 member countries e. It is the technical standards-setting organization of the UN International telecommunications union

c. its membership is comprised US telephone companies

methods prevent collisions b/w two or more computers that want to end data at the same time a. error detection b. flow control c. media access control d. addressing e. error correction

c. media access control

How many TCP fragments can be put in an IP packet? a. 2 b. as many as will fit in the Maximum Transmission SIze c. 8 d. 1 e. 4

d. 1

If the highest frequency of a circuit is 10KHZ and the lowest frequency is 900 Hz, the bandwidth available for this circuit is : a. 9Khz b. 890 Hz c. 890 KHz d. 9100 Hz e. 8900 Hz

d. 9100 Hz

With routing, computers or routers count the number of hops along a route and periodically exchange information on the hop count with their neighbors. a. circuitous b. indirect c. decentralized d. distance vector e. link state

d. distance vector

A(n) is a set of rules that determine what a layer would do and provides a clear set of messages that software at the layer needs to understand. a. policy b. standard c. regulations d. protocol e. agreement

d. protocol

In 1984, a federal judge broke up a highly contested telephone service monopoly and:

divided AT&T into two parts: one part for long distance service, and a second part, comprised of seven regional operating companies, for local telephone service

Routing between autonomous systems is called _______ routing. anterior intra interior posterior exterior

exterior

If your LAN server is overloaded, which of the following should you not consider to solve the server problem? -adding one or more additional servers -increasing the number and speed of hard disks in the server -upgrading the server's CPU with a faster CPU -replacing the cable with fiber optic cable -increasing the amount of memory of the server

replacing the cable with fiber optic cable

Select answers that are a type of VPN - intranet VPN - T-1 VPN - access VPN - extranet VPN

- intranet VPN - access VPN - extranet VPN

Select the alternative which correctly indicates the duration, in microseconds, of a transmission of 7 bits on a 1 Gbps network. -0.07 microseconds -7 microseconds -0.007 microseconds -0.7 microseconds -0.0007 microseconds

-0.007 microseconds

The capacity of a single T3 line is equivalent to the capacity of ______ T1 lines. -28 -5 -150 -8 -1800

-28

802.11g is backward compatible with which type of WLAN? -802.11n -802.15 -802.11a -802.11i -802.11b

-802.11b

Select the protocol that that switches in this diagram must support, if a frame from the external network is to successfully reach a node on the LAN. -802.3ad Link Aggregation protocol. -802.1D Spanning Tree protocol. -802.11n -PPP Multi-Link protocol. -802.1x Port Based Network Access Control protocol.

-802.1D Spanning Tree protocol.

Which IEEE standard inserts a 4-byte VLAN tag into a normal Ethernet packet? -802.1q -802.11 -802.5 -802.11g -803.3

-802.1q

Which of the following is not true about CSMA/CD? -When a collision has occurred, the computers that wish to transmit wait a random amount of time after a colliding message before attempting to retransmit -It is used in token ring protocol LANs -It is a contention-based media access control technique -The acronym refers to Carrier Sense Multiple Access with Collision Detection -Computers on the circuit 'listen' while transmitting

-It is used in token ring protocol LANs

_____________ is an emerging standard for use by layer 2 access VPNs for encapsulation. -VPN2 -L2TP -TCP/IP -PPP -Encapsule2

-L2TP

From the alternatives below, select all that correctly describe a MAC address. -An Ethernet MAC address is made up of 14 hexadecimal digits. -MAC address is a data-link layer address. -A MAC address is a layer-3 address for a client device. -People usually represent a MAC address with a binary number.

-MAC address is a data-link layer address.

Select all statements that correctly describe computers and devices that are part of a backbone network. -Only defective backbone devices lose packets. -Decreasing the memory on a backbone device usually increases performance, because the decrease results in less of a need for memory management on the device. -Most backbone devices are store-and-forward devices. -Some devices in a routed backbone network would include routers that might route packets to different subnets. -Upgrading backbone devices oftentimes results in slower throughput, because upgraded devices can overload the circuits.

-Most backbone devices are store-and-forward devices. -Some devices in a routed backbone network would include routers that might route packets to different subnets.

Select all alternatives that would likely increase demand on a regional wide-area network. -Using data compression techniques for all data in the network. -Shifting network usage from high cost times to lower cost times. -Requiring a network impact statement for all application software developed by the organization. -Moving data further from the applications and people who use them. -Shifting network usage from peak to lower demand times.

-Moving data further from the applications and people who use them.

Choose all that are features of ATM networks. ATM networks _________________. -provides extensive QoS information -are scalable -perform encapsulation of packets -are specific kinds of Ethernet networks

-provides extensive QoS information -are scalable -perform encapsulation of packets

Select all statements that correctly describe backbone network components. -Switches and routers are devices used on backbone networks, but gateways are not used on backbone networks. -Computers used by end-users are one kind of component which constitute an aspect of a backbone network. -Network cables are one kind of component which constitutes an aspect of a backbone network. -Hardware devices are one kind of component which constitute an aspect of a backbone network.

-Network cables are one kind of component which constitutes an aspect of a backbone network. -Hardware devices are one kind of component which constitute an aspect of a backbone network.

A ________ is a software that contains components and programs that allow a computer on a network to serve requests from other computer for data and provide access to other resources such as printer and file systems. -Storage Area network -Program application -client-server program -Network interface card -Network operating system

-Network operating system

A Bluetooth network is called a(n) _________, which consists of no more than ______ slave devices, in addition to a master device. -Subnet, 8 -Piconet, 7 -Siconet, 4 -Lanconet, 6 -Internet, 5

-Piconet, 7

Select all statements that correctly describe network routers - routers are unable to choose the "best" route between networks for forwarding a packet -Routers can connect two or more network-layer networks that use the same data link protocol -Routers operate at the transport layer -Routers only process messages that are specifically addressed to it at the network layer -Routers perform more processing on each message than switch

-Routers can connect two or more network-layer networks that use the same data link protocol -Routers perform more processing on each message than switch

Select all statements that correctly describe the network layer. -Routers operate at the network layer. -The network layer is obsolete. -The network layer interfaces with both the transport layer and the data link layer. -The most-used network layer protocol is IP.

-Routers operate at the network layer. -The network layer interfaces with both the transport layer and the data link layer. -The most-used network layer protocol is IP.

Select all statements that correctly describe the routed backbone architecture. -Routing takes more time than switching. -Routed backbones route packets on the basis of their data-link layer address. -Routed backbones do not forward data-link layer broadcast messages. -Routers are usually more expensive than switches. -The data-link layer and physical layer are not present on routed backbones; rather, the application layer and transport layer are directly routed via the network layer.

-Routing takes more time than switching. -Routed backbones do not forward data-link layer broadcast messages. -Routers are usually more expensive than switches

Select all statements that correctly identify switch behavior on a backbone network -Switches only process messages that are specifically addressed to it at the data link layer -Switches only process messages that are specifically addressed to it at the network layer -After receiving a message, switches build an entirely new data link layer frame and then transmit it to the correct network -Switches process all data link layer messages that appear on the network and forward them to the appropriate network on the basis of their data link layer address - switches usually connect two or more networks that use different data link protocols

-Switches process all data link layer messages that appear on the network and forward them to the appropriate network on the basis of their data link layer address

Select all statements that correctly describe the data link layer. -The data link layer is obsolete. -The data link layer manages the transport layer. -The data link layer manages the physical layer. -The data link layer is comprised of two sub layers that each have their own responsibilities.

-The data link layer manages the physical layer. -The data link layer is comprised of two sub layers that each have their own responsibilities.

Select all statements that correctly describe gateways as a backbone network component -The highest layer some gateways operate at is the application layer -The highest layer some gateways operate at is the data link layer -Gateways always connect two or more networks that use the same data link protocol, though the networks may use different network protocols -the highest layer some gateways operate at is the network layer -One common use of gateways is the enable LANs that use TCP/IP and Ethernet to communicate with mainframes that use other protocols

-The highest layer some gateways operate at is the application layer -the highest layer some gateways operate at is the network layer -One common use of gateways is the enable LANs that use TCP/IP and Ethernet to communicate with mainframes that use other protocols

A Basic rate interface provides communication circuit with _____ digital transmission channel and ____ control signaling channel. -Two 64 Kbps, one 16-Kbps -one 64-Kbps, Two 16-Kbps -23 64k-Kbps, one 64-Kbps -48 16-Kbps, two 64-Kbps -Two 128-Kbps, one 64-Kbps

-Two 64 Kbps, one 16-Kbps

Assume that there is a wide-area network (WAN) where the capacity of all its circuits and devices is currently being utilized. Select all statements that correctly describe ways to improve the performance of this WAN. -Replacing the devices which connect the backbone networks to the WAN with more powerful devices -Removing routers and therefore routes in the WAN -Removing routers and therefore routes in the network. -Upgrading the maximum bit-rate of circuits in the WAN -Upgrading the memory, processor, or I/O subsystem on the devices which connect the backbone networks to the WAN

-Upgrading the maximum bit-rate of circuits in the WAN -Upgrading the memory, processor, or I/O subsystem on the devices which connect the backbone networks to the WAN -Replacing the devices which connect the backbone networks to the WAN with more powerful devices

When the destination device receives a Ethernet frame with a bad CRC, the device does which of the following? -discards the frame -discards the corrupted portion of the frame -uses parity bits to rebuild the frame -accepts the frame

-discards the frame

Select the answer below that correctly identifies an advantage of using VPN technology. -complexity to the user -inflexibility -low cost -unpredictable traffic congestion

-low cost

Which of the following is not a key issue to be considered when selecting a WAN service? -prestige value of using a particular common carrier -reliability -capacity -control -flexibility

-prestige value of using a particular common carrier

On a backbone network, routers connect two or more networks that use __________ data link procotol(s), and __________ network protocol(s). -the same, different -different, the same -the same, the same -the same or different, the same -different, the same or different

-the same or different, the same

Backbone architecture refers to _______________. -the precise TCP/IP configuration of the devices participating a backbone. -the way in which the backbone interconnects the networks attached to it and how it manages the packets from the networks attached to it. -the precise data link configuration of the devices participating in a backbone. -the number of nodes participating in a single LAN. -the configuration of nodes participating in a single LAN.

-the way in which the backbone interconnects the networks attached to it and how it manages the packets from the networks attached to it.

Using PCM that sends 6 bits per signal and each voice grade line with a bandwidth of 3000 Hz (assume: no noise on the line), the data capacity would be bits per second.

18,000 (6 x 3000)

Select all of the alternatives below that are controlled access methods. a. Poll/Select b. Error control c. CSMA/CD d. Token Passing

a. Poll/Select d. token passing

Select all statements that correctly identify differences between TCP and UDP.. a. UDP is connectionless while TCP is connection based b. TCP segments have bits to track sequences of packets, UDP datagrams to not track packet sequences c. TCP has fields for source and destination ports and UDP does not d. TCP segments have bits for error detection, UDP datagrams to not track packet sequences e. TCP segments are typically faster than UDP datagrams

a. UDP is connectionless/TCP connection based b. TCP segments have bits to track sequences of packets/UDP does not

Select all of the alternatives below that describe an action taken to address IP address exhaustion. a. When block of addresses were distributed, fewer were given out and some large class A blocks were re-claimed b. changing routing protocols c. development of a new version of IP d. the introduction of a private addressing scheme e. Giving block A addresses to medium sized organization

a. When block of addresses were distributed, fewer were given out and some large class A blocks were re-claimed c. development of a new version of IP d. the introduction of a private addressing scheme

Select all terms that correctly identify hardware or software that is used to transform analog voice signals to digital signals to analog signals. a. codec b. voice converter c. multiplexer d. demodulator

a. codec

Synchronous transmission: a. is used to transmit a "frame" or "packet" of data at a time b. uses stop bits after each character to be sent c. uses start bits before each character to be sent d. cannot be sued on multipoint circuits

a. is used to transmit a "frame" or "packet" of data at a time

Select all of the alternatives below that are a protocol that corrects errors by identifying errors and retransmitting the data. a. sliding-window ARQ b. stop-and-wait ARQ c. ARP d. Redundancy e. Routing Protool

a. sliding-window ARQ b. stop-and-wait ARQ

Which layer of the OSI model is responsible for ensuring that all packets sent are received by the destination station by dealing with end-to-end issues? a. transport layer b. session layer c. presentation layer d. application layer e. physical layer

a. transport layer

Which of 802.11 standards offer additional security for WLAN applications? a. 802.11b b. 802.11i c. 802.11e d. 802.11a e. 802.11h

b. 802.11i

A timer is set when is sent out a. control data b. a frame c. all of the other answers d. and ACK e. a NAK

b. A frame

From the alternative below, select the protocol that is most likely to be implemented at the data link layer of the internet or OSI model a. IP b. Ethernet c. TCP d. FTP e. HTTP

b. Ethernet

The protocol that makes it possible for a Macintosh web browser to be able to retrieve a web page from a microsoft web server is called a. Internet Message Access Protocol b. Hypertext Transfer Protocol c. Hyperlink Transfer Protocol d. File Transfer Protocol e. Simple Mail Transfer Protocol

b. Hypertext Transfer Protocol

Which one of the following statements is true? a. Host-based architecture is the most scalable architecture b. P2P networks are very resilient to the failure of any one computer c. The web was first conceived in 1998 by Tim Berners-Lee d. The infrastructure costs of client-server architecture is greater than that of Host-based architecture

b. P2P networks are very resilient to the failure of any one computer

Assume there is a log which contains the following TCP/IP related information for TCP/IP network traffic on a local area network: Source IP address Destination IP address Source port Destination port What information would be needed to uniquely identify a TCP connection? a. Destination IP , Destination Port b. Source IP , Destination IP , Source Port, Destination port c. Source IP, Source Port d. Source IP, Destination IP e. Source Port, Destination Port

b. Source and Destination IP + Port

From the alternatives below, select all that correctly describe Wireless LANs (WLANs). a. WLANs effectively use a switched architecture b. WLANs effectively use a shared bus architecture c. WLANs are effectively Half Duplex d. WLANs are effectively full duplex

b. WLANs use a shared bus architecture c. WLANs are half duplex

is an effective way to deal with attenuation. a. adding fluorescent lights b. adding repeaters or amplifies to a circuit c. shorting out a circuit d. changing multiplexing techniques

b. adding repeaters or amplifiers to a circuit

With a client-based architectures, on fundamental problem is that: a. the clients must perform the data storage logic b. all data on the server must travel to the client for processing c. the clients each must store all the data d. the server does not have any data storage capability e. the host or server must perform presentation logic, application logic, and data access logic all at the same time

b. all data on the server must travel to the client for processing

How many unique identifies would a 17-bit address field provide? Include any broadcast and network addresses identifies in your calculation? a. 32768 b. non c. 131,072 d. 34 e. 17

c. 131072

An n-tier architecture consisting of more than three tiers: a. uses only two sets of computers in which the clients are responsible for the app and presentation logic, and the servers are responsible b. is generally less "scalable" than a three-tiered architecture c. is generally more "scalable" than a three-tiered architecture d. puts less load on a network than two-tiered architecture because there tends to be less communication among servers

c. is generally more "scalable" than a 3-tiered architecture

Which standards body is responsible the development of LAN standards? a. ITU-T b. ANSI c. IETF d. IEEE e. ISO

d. IEEE

When a network protocol utilizes Automatic Repeat Request (ARQ): a. the common carrier Automatically Returns Queries to the subscriber upon receipt of such queries b. a fiber optic cable meets the American Registered Quality, a certification standard for use in high-quality data communication transmission lines c. a sender is using a parity scheme called Array Resource Quality the common carrier Automatically Returns Queries to the subscriber upon receipt of such queries d. a receiver that detects an error in a message simply asks the sender to retransmit the message

d. a receiver that detects an error in a message simply asks the sender to retransmit the message

The of a circuit determines a circuit's capacity. a. frequency b. phase c. amplitude d. bandwidth e. loudness

d. bandwidth

In communication protocols, _________ are used to convey the user's meaning. a. flag bits b. stop bits c. start bits d. information bits e. overhead bits

d. info bits

Ethernet is a ___________ protocol, which means that there is no guarantee on the delivery time of a message. a. Guaranteed delivery b Deterministic c. All of the the other answers are correct d Non-deterministic e. Collision free

d. non-deterministic

Assume that a network interface card is configured as follows: IP Address: 192.168.37.17 Subnet Mask: 255.255.255.240 Select the subnet-directed broadcast address from the alternatives below. a. 192.168.37.0 b. None of the other answers are correct c. 192.168.37.255 d. 192.168.37.240 e. 192.168.37.31

e. 192.168.37.31

A coding scheme that uses 8 bits to represent each character is capable of representing different characters. a. 512 b. 8 c. 128 d. 16 e. 256

e. 256

How many unique identifiers would a 12-bit address field provide? Include any broadcast and network addresses identifiers in your calculation. a. 12 b. 24 c. None d. 1024 e. 4096

e. 4096

If each sample uses 32 Bits, and the number of samples taken each second is 4,000, then what is the transmission speed of the circuit? a. 64 Kbps b. 125 bps c. 32,000 bps d. 125 Kbps e. None of the above

e. none of the above

________ is the process of sending a signal to a client that gives its permission to transmit or asks it to receive. a. contention b. CRC c. Pooling d. carrier sense e. polling

e. polling

In a three-tier architecture, the software on the client computer is responsible for a. application storage b. application logic c. data access logic d. data storage e. presentation logic

e. presentation logic

is a unit if signaling sped that indicates how often the signal changes on a communication circuit a. bits per second rate b. trellis rate c. phase rate d. attenuation rate e. symbol rate

e. symbol rate

Media access control: a. is not very important in local area networks b.does not control when computers transmit c.is not very important in a multipoint configuration d. is not very important in point-to-point with full duplex configuration e. is not very important in a point-to-point with a half duplex configuration

is not very important in point-to-point with full duplex configuration

American National Standards Institute (ANSI)

is the coordination organization for the united states' national system of standards

When an access point configured to use EAP first discovers a new client the first thing the access point does is: -requires the user authenticate against a login server -asks the client to provide a WEP key -issues a WEP key to the client -grants the client access to the network -None of the other answers are correct

requires the user authenticate against a login server