IT300 FINAL STUDY(QUIZZES/HWS/STUDYGUIDEQUESTIONS&ALLTERMSRELEVANTINFOINPPTS)

Fiber Distributed Data Interface TAKEN OVER BY

Metropolitan Ethernet Network (MEN)

Wireless routers will have both DTE and DCE interfaces

TRUE DCE and DTE describes the direction of data flow, transmit and receive

HALF-DUPLEX

TWO WIRE PAIRS

VoIP

digitized voice stream using Real Time Protocol (RTP) Layers 5 to 7 over UDP/IP Layers 3 & 4 - supported via ISP

OFDM

distributes the data over 256 narrow-band subcarriers, of 4kHz bandwidth each (high spectral efficiency)

PASSIVE SPLITTER

divides downstream signal from OLT into multiple signals to ONUs and ONTs

When implementing OFDM on either WiFi or ceullar RF link, the use of guard bands between sub-carriers is not necessary.

true

Collision detect

—If two or more stations on the same network begin transmitting at approximately the same time, their data frames will collide making transmissions unreadable

Domain Name System (DNS)

hierarchical decentralized system for translating IP addresses to domain names (ex., www.gmu.edu), and visa versa Even the shorthand dotted decimal format is difficult to remember and use. Translations are made from domain names and Uniform Resource Locators (URLs) into IP addresses and vice versa

_______ is a protocol that is used to communicate routing information within an autonomous network.

igp(interior gateway protocol)

PBX

is a switch owned by a user

DCE

receives the data

Receive and send windows(tcp)

represent the amount of data that can be received or sent is configurable - this determines the size buffers needed

SWITCHED VIRTUAL CIRCUIT

similar to circuit switched only virtual

An ITU-2000 goal was to provide voice quality comparable to the PSTN. (T/F)

true

Centralized control

- Central station determines when the stations on the LAN can access the shared medium (polling, tokens) - ex., Token Ring, FDDI

Medium Access Control (MAC)

- defines the process by which devices on the network can access the shared medium - OSI Layer 2 (Data Link) protocol

Customer Premises Equipment (CPE)

- e.g., telephones, PBXs, computers, facsimile, etc.

Logical Link Layer (LLC)

- handles communication between upper layers and lower layers Takes IP and adds control info Implemented in software (driver sw for Network Interface Card, NIC)

Classified as an Interior Gateway Protocol (IGP)

- i.e., internal to an autonomous network (routers that share a common protocol)

Metropolitan Area Network (MAN)

- larger area than a LAN but smaller than a WAN Typically operated by a single organization or service provider

Demarcation Point (demarc)

- point of delineation between CPE and the carrier network

International Gateway Facilities (IGF)

- provide connectivity between international carriers

SWITCHED

- use FDX Ethernet Switches Employs two or four wire pairs (i.e., four or eight wires) No collisions occur

For a WLAN system with a transmit power of +10dBm, transmits antenna gain of 10dBi, FSL=-100dB, and receive antenna again of 1dBi, what is the power received in dBm?

-79 dBm (JUST ADD THE NUMBERS)

100BaseT Ethernet means what?

100Mbps, baseband, twisted pair

Cat5e medium has a capacity of 125 MBaud. By applying 4B5B coding over two pairs of wires, full-duplex (FDX) what data rate capacity can you obtain.

100mbps------ 4/5 OF 125(??)

Four generations of standards

1G: Analog 2G: Digital 3G: First with sufficient speeds for data networking, packets gateways 4G: Truly broadband mobile data using packets

Channelized T-1 carrier is a dedicated digital link that consists of _______ DS0s, ______ bps per DS0, _______ bits per frame, ________ frames per second.

24 DS0s, 64 kbps per DS0, 193 bits per frame, 8000 frames per second

What is the bit rate for a DS0?

64kbps

A SONET frame consists of ________ bytes per frame, ________ frames per second, which support ______ DS0s.

810 bytes/fr, 8000 fr/sec, 672 DS0s per frame

Select the correct statement(s) regarding CENTREX.

CENTREX systems reside at the service providers central office, and the operations and maintenance responsibilities belong to the service provider

Shared Ethernet

CSMA/CD

three-way handshake

Client initiates communications by sending a TCP segment with SYN (Synch Sequence No.) flag set 2. Server responds with ACK (Acknowledgment) flag set 3. Client sends ACK which establishes session

What happens when a collision is detected on a CSMA/CD link?

Closet node detecting collision sends out a jamming signal

Communications Act of 1934

Congress passed the Communications Act of 1934, Federal Communications Commission (FCC) was established

Mobile telecommunications switching office (MTSO) (aka Mobile Switching Center, MSC)

Connects calls between mobile units Connects mobile calls to the wired PSTN or Internet

An Ethernet baseband LAN uses Cat5e UTP. One pair (two wires) is used for transmit data and another pair is used for receive data. Each pair can support 125 MBaud. 4B/5B coding is also used. What is the total data rate that can be supported on this LAN assuming an M=2 modulation scheme?

Correct b. 100MBPS

ADSL implements discrete multi-tone (DMT) modulation. Select the correct statement

DMT uses OFDM with 256 overlapping sub-carriers of 4kHz bandwidth each

Select the correct statement(s) regarding DNS.

DNS services translates domain names (URLs) to an IP address

Which group below represents ways by which we can access broadband networks?

DSL(Digital Subscriber Line), CATV, PONS(PASSIVE OPTICAL NETWORK), WLL(WIRELESS LOCAL LOOP)

Media Access Control (MAC)

Data encapsulation - framing, addressing, error detection Media access - placement of frames on the media Implemented in NIC hardware Contention-based: CSMA/CD or CSMA/CA

Ethernet 802.3 is characterized as:

Decentralized control, non-deterministic access control

Ethernet 802.3

Decentralized, Non-determinant access

LOCAL LOOP

Dedicated circuit Point-to-Point Protocol (Layer 2) typically used

100Base-T

FAST ETHERNET 100BaseT, 1000BaseT, 10GBaseT, FDDI

What is true regarding the comparisons between Asynchronous Transfer Mode (ATM) and Frame Relay (FR)?

FR consists of variable sized data frames, whereas ATM is comprised of fixed cell size

ISO is a regulatory organization. (T/F)

False

WDM cannot be used with SONET. (T/F)

False

User Data Protocol (UDP) -

OSI Level 4, Transport Layer Simplifies host-to-host protocol Unreliable, connectionless No sequencing, error control or flow control Application program assumes full responsibility Ideal for DNS, SNMP, VoIP, etc.

Far-End Crosstalk (FEXT)

Occurs at the far end of the loop (near the customer) Not a great issue for ADSL since customer side does not have to deal with large bundles of UTP (i.e., bigger issues for corporations where there are more bundles of UTP pairs from the CPE)

Near-End Crosstalk (NEXT)

Outgoing stream is at maximum strength Incoming stream is at minimum strength Signals can couple if Attenuation-to-Crosstalk (ACR) ratio is not maintained

1982 -The Modified Final Judgment (MFJ)

The Justice Department's primary goal for breaking up AT&T was to spur innovation and competition 1984, Jan 1 Divestiture took place- 22 former Bell Operating Companies (BOCs) were reorganized into seven Regional Bell Operating Companies (RBOCs). (aka Regional Holding Companies (RHCs))

Network Address Translation protocol (NAT)

The NAT server replaces the internal address with a corporate global IP address The NAT caches the outgoing requests, and then matches incoming packets with outgoing requests NAT falls short for some protocols such as IPSec, where packet headers are digitally signed and must remain unmodified from source to destination

Carterfone decision. 1968

The restriction against interconnecting to AT&T's telephone network was challenged in 1965 and eventually lifted in 1968 through the Carterfone decision. 1968, the FCC "Carterfone" decision

DTE

Transmits the data

In-band signaling is implemented on UTP local loops?

True

With SONET, the optical building block is termed an OC-1, and its electrical counterpart is STS-1. Both OC-1 and STS-1 equates to a capacity of 51.84 Mbps.

True

Which of the following cellular concepts can be used to increase the number of subscribers within a single cell.

a. Frequency borrowing b. Cell splitting c. Cell sectoring Correct d. All of the above

Select the correct statement(s) regarding the PBX.

a. Organizations using PBXs must have technical expertise on their staffs to operate and maintain them b. A PBX can support both analog and digital communications c. Numerous PBXs can be configured as a distributed network to support organizational requirements Correct d. All are correct***

Select the correct statement(s) regarding Synchronous Optical Network (SONET).

a. STS and STM both represent the electrical signaling equivalent to the optical signal b. SONET and SDH are both based-upon OC optical carriers c. SONET and SDH both implement a synchronous timing scheme to ensure accurate data clocks Correct d. All of the above are correct

What are some ways to accomplish full-duplex (FDX) digital communications on guided medium at the physical layer (OSI Layer 1)?

a. Separate digital receive and transmit paths onto their own physical channels/circuits b. Modulate receive and transmit channels onto different carrier frequencies, thus allowing FDX on the same medium c. Analog receive and transmit can operate FDX on the same guided physical medium (e.x., local loop PSTN) Correct d. All of the above

In order to achieve 1Gbps (1GbE) over Cat5e cabling, what needs to be done?

a. Use all four wire pairs in full-duplex b. Apply PAM-5 modulation to achieve M=4, N=2 c. Use hybrids that enable full-duplex transmission over a single wire pair Correct d. All of the above

Your receive sensitivity has an [SNR]=30dBm. Through link analysis you find that you have an actual receive [SNR]=10dBm. What is your link margin, and can you close the link?

a. You have no link margin and cannot close the link

Which of the following are part of the Passive Optical Network (PON) architecture?

a.Optical Splitters b. WDM c. Optical Line Terminal Correct d. All of the above

Data Over Cable Service Interface Specification (DOCSIS)

addresses support for data transmission DOCSIS cable modems include TDMA and QAM

Switches

are located within the Central Office (CO)

When designing a cellular system, a N=1 cell reuse pattern means:

b. All allocated frequency channels in the system can be used in each cell

_________ established the Federal Communications Commission (FCC)

b. Communications Act of 1934

Which is a way to achieve digital full-duplex (FDX) communications over the two-wire UTP local loop?

b. FDM

hard hand-off

breaks the connection with one base station before connection is reestablished with another

Determine the Noise Power in dBm given the following: Boltzmann's constant k=1.38E-23 (J/K), T=275 Kelvin, B = 5MHz.

c. -107.23 dBm

Given a [S]=-80dBm and [N]=-130dBW, what is the [SNR]?

c. 20 dB

The combination of a ________ and ________ is called a "socket".

c. IP address, port

What is the purpose of the timeout period within the TCP protocol?

c. Is the time period in which an ACK must be received before retransmission in order to prevent duplicate packets from being sent

Determine the power received (Pr) at your laptop given the following: Access Point (AP) Tx power = +20dBm, AP antenna gain, Gt=8dBi Free-space-loss (FSL) = -120dB Laptop antenna gain, Gr=3dBi

c. Receive Power, Pr = -89dBm(ADD ALL TOGETHER)

What is the function of the IPv4 NAT protocol?

c. Replaces internal IPv4 addresses within an intranet, with an external Internet IPv4 address

Traffic channels

carry voice or data connection between users

source ports

client application

TRUNKS

connect network switches together which form the network Trunks can be wired, fiber optic, microwave, satellite, etc.

Optical Network Terminal (ONT):

connects optical fiber to copper at far end (CPE) (FTTH, FTTP)

FCC Telecommunications Act of 1996

convergence of data networking • Allowed new entrants into the telecommunications market (i.e., dot.com era) Bells were allowed to offer long-distance and Internet access • Bells would have to sell access to their existing landline networks at a fair price Entrepreneurs began building massive fiber networks • Many failed "start-up" • Frenzy of mergers and acquisitions in the telecomm. Industry

What is the function of the IPv4 ICMP (Internet Control Message Protocol )protocol?

d. An error reporting protocol used by routers to send messages regarding delivery problems

Determine the [SNR] in decibels at the receiver given the following: Pr=-80 dBm T (Kelvin degrees) = 295 Kelvin B (bandwidth) = 1kHz

d. [SNR]= 63.9dB

Numbering Plan Administration (NPA)

enables connectivity to other telephones MAX 15 DIGITS

Open Shortest Path First (OSPF)

enables the routing of packets through an autonomous network

Inter-cell interference coordination (ICIC)

ex. ,LTE Reduces interference when the same frequency is used in a neighboring cell Goal is universal frequency reuse (N = 1) Must avoid interference when mobile users are near each other at cell edges Interference cancellation, coordination, and avoidance are used

What is the function of Inter-cell interference coordination (ICIC)?

ex. ,LTE Reduces interference when the same frequency is used in a neighboring cell Goal is universal frequency reuse (N = 1) Must avoid interference when mobile users are near each other at cell edges Interference cancellation, coordination, and avoidance are used

Data Terminal Equipment (DTE)

ex., computers, servers, etc.

Data Communications Equipment (DCE)

ex., switches, etc. DTE and DCE do not describe hardware, they describe the interface

A NAT is used to send network-level messages between routers. (T/F)

f

CENTREX systems reside at the service providers central office, however, the operations and maintenance are still the responsibility of the user organization.

f

DHCP protocol is used to map internal (intranet) IP addresses to Internet addresses.

f

DTE and DCE define the category (i.e., type) of equipment (i.e., terminals are DTEs, network equipment are DCEs).

f

FEXT is considered more problematic than NEXT on ADSL connections. As long as proper ACR ratios are observed, the probability of successful data exchange will be high.

f

IEEE 802.3 Ethernet must always use CSMA/CD whether in a switched or shared configuration.

f

IP can be either connection-oriented or connectionless. (T/F)

f

IPv4 address 300.197.020.110 is a legal address. (T/F)

f

IPv4 was designed to provide security and QoS. (T/F)

f

Like TCP, UDP segments are delivered in sequence. The only difference is the number of bits within the segment header.

f

MENs implements shared 802.3 standards. (T/F)

f

OFDM cannot be used with other modulation techniques since it is itself a modulation technique.

f

PON requires active components in order to reach user locations. (T/F)

f

TCP is a connection-oriented network layer protocol. (T/F)

f

TCP source and destination ports are addresses used to identify the communicating node.

f

The Common Channel Signaling (CCS) is a separate "in-band" signaling network used by the PSTN to provide signaling , connection and control functions to users on the network.

f

The IEEE 802.3 Ethernet standard only describes the Data Link Layer of the OSI Reference Model. Therefore, any physical medium can be used.

f

The IP address 192.256.181.300 is a legal IPv4 address.

f

The International Organization for Standardization (ISO) is a government regulatory organization that oversees frequency licensing and transmit power limits.

f

The PSTN is a label only applicable to the old analog UTP telephone networks. The PSTN does not incorporate mediums such as wireless or fiber optics.

f

With SDH, the STM is the electrical equivalent to the OC optical signal. STM-1 equals STS-1, with a data rate of 51.84Mbps.

f

soft hand-off

f makes the new connection before breaking the old one Much better for the transmission of data

UDP is an connection-oriented OSI Layer 4 protocol.

f- CONNECTIONLESS

ARP maps TCP or UDP addresses to IP addresses. (T/F)

f-map ip addresses to physical MAC address

DHCP maps intranet and Internet IP addresses. (T/F)

f: NAT does

The Telecommunications Act of 1996 reaffirmed that incumbent local exchange carriers (iLEC) such as the Bell companies, could not be forced to sell access to their communications infrastructure to competitors. This is a key factor that led to the "dot.com bust".

f: The goal of this new law is to let anyone enter any communications business -- to let any communications business compete in any market against any other

CENTRAL OFFICE

facility where local loops connect to the PSTN infrastructure

ADSL is based upon PSTN local loop pairs from the Central Office (CO). As such, subscribers must specifically connect to the Internet (i.e., they're lines are not connected until they physically connect or go "off-hook" to make a connection or call).

false

Ethernet LANs are designed for both centralized control and deterministic access control.

false

FEXT is a bigger issue than NEXT. (T/F)

false

It is possible for FDX switched Ethernet to have collisions. (T/F) false

false

PONS implements SONET(Synchronous Optical Networking) optical frames and central timing. As such, capacity is high thus enabling the transmission of numerous HD channels as well as high speed access to the Internet

false

PVC and SVC can be applied to analog networks. (T/F)

false

SONET STS-1 and SDH STM-1 have the same data rates. Both describe the optical portion of SONET. (T/F)

false

Since the WLAN (IEEE 802.11) operates in free space (unguided), separate frequency channels are used for transmit and receive. As such, there is never a possibility of data collisions.

false

The Internet Protocol (IP) must guarantee packet delivery since it was designed to serve as a survival network.

false

You can never connect a DCE to another DCE device.

false

4G cellular implements both OFDMA and CDMA. (T/F)

false- - LTE-Advanced & Mobile WiMAX - OFDM, OFDMA

Switched Ethernet LANs operating in a full-duplex (FDX) manner must implement Carrier Sense Multiple Access (CSMA), Collision Avoidance (CA) methods. Even when implementing CSMA/CA, collisions can still occur.

false- FDX: NO COLLISIONS

Cell sizes are decreased to support increasing number of users in an area

frequency reuse increases significantly more base stations needed

In-Band Signaling & Control functions

functions take place over the same physical path as the conversation Disruptive and intrusive Seldom employed except on analog local loops

ZigBee (IEEE 802.15.4)

intended to be simpler, more flexible, less expensive than Bluetooth

Passive Optical Network (PON)

is a fiber optic local loop network No active electronics (ex., repeaters, etc.) Use of inexpensive passive optical splitters to deliver signals PON splitters provide a tremendous fan-out of fiber to a large number of end points Use of a passive vice active network results in significant cost savings

Generic Digital Subscriber Line (xDSL)

is a group of digital access technologies for residential and business customers

Scatternet

is a network of multiple piconets

Common Channel Signaling (CCS)

is a robust sub-network that supports signaling and control Signaling System 7 - current ITU-T version

Multiprotocol Label Switching (MPLS)

is an IETF specified network architecture that provides quality of service (QoS) across unreliable networks such as IP

IP

is key to enabling the Internet Basic building block - packet (aka datagram) Connectionless Protocol - packets enter network independent of one another - no connection between end points established Each packet must contain source and destination addresses No guarantee of correct packet sequencing Best Effort

Optical Line Terminal (OLT):

located at the CO/Head End - serves to terminate optical local loop to network

Address Resolution Protocol (ARP)

maps IP addresses to Medium Access Control (MAC) layer addresses found in Layer 2, data link networks. As the IP packet is received by the local network, ARP broadcasts the IP address of the packet to all workstations on the local network. The intended workstation recognizes and then claims the incoming packet.

DMT (Discrete Multi-tone)

modulation uses OFDM (Orthogonal Frequency Division Multiplexing) Provides very high capacity transmission over short distance

Select the protocol that provides network quality-of service (QoS) by appending an FEC (Forwarding Equivalence Class) to each datagram.

mpls(Multiprotocol Label Switching Protocol)

A scatternet is comprised of ___________.

multiple piconets

Deterministic access control

node that is granted access has a guarantee that it can transmit data without collisions

VIRTUAL CIRCUIT

physical circuit shared by other users, but transparent to the user

Border Gateway Protocol (BGP)

protocol used to enable routers in different autonomous networks to exchange routing and reachability information

Traditional PSTN

provided 4kHz analog voice

Internet Control Message Protocol (ICMP)

provides feedback to networked routers regarding issues/problems encountered during the processing of packets ICMP messages provide error reporting such as invalid port numbers or IP addresses, destination unreachable, redirection of packets, etc. Does not make IP reliable For security reason, ICMP often not allowed within a network

Wireless local loops (WLL)

provides user local loop connectivity via unguided RF or IR Advantages include Quick deployment Flexibility in assigning bandwidth Ease of reconfiguration Disadvantages include: Interference Limited distance LOS Licensing required Security

The typical pattern for frequency reuse

repeating 7-cell pattern K= number of frequencies in the system N= cell reuse pattern K/N = number of freq. ch. per cell

dsl(digital subscriber line)

s provisioned over UTP local loop facilities

What are some disadvantages for WLL?

see lecture 8 slide

destination ports

server application

What happens when the TCP timeout period has expired?

source resends segments

4B5B implementation results in an increase in overhead of 20%. (T/F)

t

802.11 employs either DSSS or OFDM and operates in the ISM frequencies. (T/F)

t

A SONET frame must have a frame rate of 8000 fr/sec in order to support 672 DS0 channels.

t

A channelized T-1 frame must have a frame rate of 8000 fr/sec in order to support 24 DS0 channels.

t

ACDs are considered switching PBXs that employ IVRs. ACDs can be networked across the PSTN.

t

ATM over SONET is provides high data rate capacities, predictable delays and quality-of-service; however, both ATM and SONET are complex technologies to implement.

t

Carrier Ethernet, describes the use of the Ethernet protocol for MAN and WAN connectivity at the OSI RM Layer two. With CE 1.0, E-Line, E-LAN and E-Tree services are offered.

t

TCP window sizes are used to control network congestion. (T/F)

t

The 1982 Modified Final Judgment (MFJ) led to the 1984 divestiture of the Bell Operating Companies (BOC) resulting in the creation of seven independent Regional Bell Operating Companies (RBOCs).

t

The IPv4 subnet mask 255.255.0.0,belongs to a Class B network.

t

The Kingsbury Agreement essentially re-affirmed the idea that AT&T could continue to operate as a regulated monopoly free from competition.

t

The PSTN makes use of both in-band and out-of-band signaling and control.

t

The demarcation point separates the CPE from the service provider (carrier) network. It also separates network responsibilities between the customer and the network provider.

t

ADSL

takes advantage of this unused frequency BW available on UTP local loop Asymmetric refers to the fact that more bandwidth is dedicated to the downstream (to the customer) than to the upstream (to the network)

Out-of-Band Signaling & Control

takes places outside of conversation channel No interference between signaling/control and conversation

Optical Network Unit (ONU):

terminates the PON and interfaces with other medium such as ADSL, coax, etc. (FTTC, FTTN)

ACDs are PBXs that switch incoming calls to a call center. ACDs typically employ Interactive Voice Response (IVRs). (T/F)

true

DOCSIS cable modems use TDMA and QAM.

true

DOCSIS described common interface specifications for the CATV industry, which were previously non-existent.

true

DTE and DCE designations are important because it describes the direction of both transmit and receive signals on networks using guided mediums such as CAT 5e UTP.

true

Data collisions will not occur when implementing full-duplex (FDX) switched Ethernet.

true

During a network soft hand-off between cells, the ME (Mobile User) is continuously connected to both BTS' until the hand-off is complete.

true

Guided Ethernet LANs operating in a half-duplex (HDX) manner must implement Carrier Sense Multiple Access (CSMA), Collision Detection (CD) methods.

true

IEEE 802.11g and 802.11n are both backward compatible with 802.11b.

true

IMT-Advanced directive requires an all IP packet switched network. (T/F)

true

MPLS (Multiprotocol Label Switching) specifies a network architecture that uses labels attached to IP datagrams in order to provide Quality-of-Service (QoS).

true

The IEEE 802.11 Control Module (CM) provides bridge and router functionality between the mobile user air interface and the wired network.

true

The T-1 carrier is specific to North America. Other carriers such as E-1 and J-1 exist; however all of these standards are based upon the standard uncompressed DS0 which represents a 4 kHz voice grade channel.

true

The Unchannelized T-1 is not divided into 24 DS0s, and therefore can support data applications that do not neatly fall into 64kbps channels.

true

UDP is a connectionless protocol at the Transport Layer. Like IP, UDP is considered an unreliable protocol

true

the DSLAM is an OSI Layer two device that resides at the central office and communicates with DSL modems located at a users site.

true

Shared

use of CSMA/CD over shared bus, HDX HDX Ethernet is not efficient, limited to 10BaseT Hubs typically work in HDX mode

QAM

used on each subcarrier (dynamically rate adaptive, from 1 to 15 bits per baud (M=2 to 32,000 levels per symbol)

Control channels

used to exchange information having to do with setting up and maintaining calls

What is a loading coil?

used with analog PSTN to counter UTP capacitance - required to be removed for ADSL

Cable Television or Community Antenna Television (CATV)

was originally used to distribute TV programming over coaxial cable, today is support two-way communications

Multiple access

—Numerous stations share baseband medium

1913-Kingsbury Agreement:

• The Wilson administration considers anti-trust proceedings • Mr. Kingsbury (AT&T vice president) agrees to stop acquisition of other telcos • Interpreted as an agreement to allow AT&T to function as a regulated monopoly from 1913 to 1984.

Permanent Virtual Circuit

physical routing always the same

Standardization:

3GPP, 3rd Generation Partnership Project GSMA, GSM Association IEEE, Institute of Electrical and Electronics Engineers ETSI, European Telecommunications Standards Institute Etc...

What are ways to address increases in subscriber numbers?

a. Frequency borrowing b. Cell splitting c. Cell sectoring

FULL-DUPLEX

4 WIRE PAIRS

What is the bandwidth of a voice grade circuit?

4kHz

IPV6

128 bits

ISO - International Organization for Standardization

Non-governmental organization (NGO) Comprises national-level standards organizations from 156 countries (United States rep. is ANSI - American National Standards Institute) ISO has great influence over a wide range of international standards (e.g., OSI - Open Systems Interconnection Reference Model)

Public Data Network (PDN)

PDN protocols map to Layers 1 & 2 of the OSI RM (T-1, SONET, WDM/DWDM, ATM, FR, Carrier Ethernet, etc.) PDN is part of the PSTN PDN ex.: WAN (private and public), Internet supports digitized voice using PCM techniques - uncompressed 64kbps voice grade channel (Layers 1 & 2)

Local Loop

(UTP, fiber optic, coaxial, WLL, etc.)

Non-deterministic access control

(aka contentious MAC) - no guarantees

CSMA/CD -

- common MAC method used in HDX guided Ethernet LANs

A DS0 has a data rate of 64 kbps. Why?

A DS0 is equivalent to a single voice grade channel with a bandwidth of 4kHz. Using PCM, the equivalent uncompressed data rate is therefore 64 kbps

Select the correct statement(s) regarding DCE and DTE interfaces.

A DTE interface must be connected to a DCE interface unless a cross-over cable is used

Select the correct statement(s) regarding TCP.

A TCP window size can change depending upon network conditions

What is an Internet Exchange Point (IXP)?

A physical infrastructure that enables ISPs to exchange Internet traffic between networks through peering agreements

NOTE

Active optical networks: 100km, Passive optical networks 20km

DSL Access Multiplexers (DSLAM)

Acts like a network switch (Layer 2)

International Telecommunication Union (ITU) 4G directives for IMT-Advanced

All-IP packet switched network

Select the correct statement(s) regarding cellular systems

As cell sizes shrink, the complexities of switching mobile traffic between cells increases

hand-off

As the ME moves from one cell to another, the call switches from one BS antenna to another through a process known as

ACD

Automatic Call Distributors (ACDs) PBXs that switch incoming calls to a call center Employs Interactive Voice Response (IVRs)

Dynamic Host Configuration Protocol (DHCP)

Automatically assigns IP address, subnet mask, etc. to communicating device DHCP servers maintain a pool of IP addresses that can be temporarily assigned to a device

Base Station (BS) or BTS (Base Transceiver Station)

Band of frequencies allocated

What is a "demarc"? (point)

Division between CPE and service provider equipment and responsibilities the physical point at which the public network of a telecommunications company (i.e., a phone or cable company) ends and the private network of a customer begins - this is usually where the cable physically enters a building.

Decentralized control

Each station assumes responsibility for controlling its access to the shared network - ex., Ethernet

CARRIER SENSE

Each station continuously listens for traffic

For 802.15 Bluetooth what does FH-TDD-TDMA stand for?

Frequency Hopping Spread Spectrum, Time Division Duplex, Time Division Multiple Access

Switched Ethernet (

HDX or FDX) FDX - no collisions

Enables frequency reuse in non-adjacent cells

Higher frequencies experience higher attenuation over distance

Select the correct statement(s) regarding the IP protocol

IP is a best effort protocol and does not address the correct sequencing of packets

regulatory

ITU-R, International Telecommunications Union - Radio Communication Sector FCC, Federal Communications Commission

IXP (Internet Exchange Point)

IXP physical infrastructure enables different Internet Service Providers (ISPs) to exchange Internet traffic between networks through mutual peering agreements .

JAMMING SIGNAL

If any node on the network detects a data collision, that node sends a jamming signal All devices back off, wait for a random period of time before attempting to transmit

Splitters or Modems

Installed in matching pairs Splitter on the network side typically embedded into the DSLAM

What is the 802.15 Bluetooth "access code"?

Is defined by the master node and associates incoming packets to the piconet

What is the importance of NPA(Numbering Plan Area)(AreaCode)?

It provides a standard telephone numbering scheme that enables call connection at the international level

What was the significance of the 1982 MFJ?

It was a judgment that led to the divestiture of AT&T

When packets enter a MPLS-based network,

Label Edge Routers (LERs) give them a label (identifier).

Femtocells

Low-power, short-range self-contained base station In residential homes, easily deployed and use the home's broadband for backhaul (i.e., Internet)

What is network densification? What does N=1 mean?

N=1 means All allocated frequency channels in the system can be used in each cell universal frequency reuse

DMT modulation uses

OFDM (Orthogonal Frequency Division Multiplexing)

________ is located at the PONS "head-end" and is used to terminate the local loop to the network.

OLT(Optical line termination)

Identify the group of devices that support PONS.

OLT, ONU, ONT

Transmission Control Protocol (TCP)

OSI Layer 4 protocol Connection-oriented protocol over virtual circuits Provides packet sequencing End-to-end flow control Error control Guaranteed delivery through acknowledgements

You belong to a large organization with a highly skilled IT staff. You wish to have complete control over the organization's switching network. The organization has offices across the nation. Which system do you select?

PBX

8 bluetooth devices can be linked together in a

PICONET

Packets partitioned into Forwarding Equivalence Classes (FEC)

Packets belonging to the same FEC follow the same network path FEC assigned to each packet is called a label Frees routers within the MPLS network from having to perform header analysis of each packet Independent of the Layer 2 &3 protocols Maps IP addresses to fixed length labels

Circuit Switched -

physical circuit exclusively assigned for duration of call, then released

IEEE 802.3 Logical Link Layer (LLC) is responsible for what?

Providing communications between the data link layer and the network layer

ITU

Regulation is heavily influenced by the ITU-T International Telecommunication Union - chartered by the United Nations (UN) ITU-T is responsible for NPA at the international level, each nation or region has similar responsibility within their domains ITU-T E.164 recommendation specifies NPA convention - Maximum of 15 digits

What was the significance of the Carterfone decision?

Ruling allowed non-ATT devices to be connected electrically

What does the DSL splitter do?

Separates analog and digital portion of the local loop

CENTREX

Service provider owned switch offered to users Provides similar functionality as a PBX for a monthly fee Users do not have to have technical expertise

Wireless Personal Area Networks (WPAN)

Short-range communication Low-cost, low-energy to provide long battery life

dsl splitter

Supports analog voice and Internet data simultaneously through a

Select the correct description of a DSL Splitter.

The DSL Splitter separates the analog signal from the digital signal

Dedicated Circuit

physical circuit leased for exclusive by user

the period in which an ACK must be received before retransmission - this prevent duplicate packets from being sent and received

Timeout period

NAP (Network Access Point)

Today known as Internet Exchange Points.

PBX

User-owned and operated switch vice service switch Large organizations Requires user to have technical expertise

PON employs_____and security measures such as encryption

WDM

What is a true statement regarding WDM?

WDM is more cost effective than SONET, although they can be used together in a hybrid system

(WLANs

WIRELESS LANS 802.11a, 802.11b (DSSS), 802.11g (OFDM), 802.11n (MIMO), 802.11ac (Gigabit WiFi)

Two most prevalent 3G standards

Wideband CDMA (WCDMA) CDMA2000

1956 Hush-a-Phone decision

a Supreme court ruling that allowed devices that were not manufactured by AT&T to be attached mechanically to AT&T telephones.

Worldwide Interoperability for Microwave Access (WiMAX)

a broadband wireless access (BWA) solution that has a maximum range of approximately 30 miles ―Last Mile‖ solution 10-66 GHz licensed band, fixed LOS Frequency bands well suited for small to large offices OFDM Up to 75Mbps

PTSN(PUBLIC SWITCHED TELEPHONE NETWORK)

a collection of mostly digital equipment such as switches connected by a variety of communications links (UTP, fiber optic, microwave, satellite, cellular, etc.)

ACR

a ratio of the receive power over noise interference caused by cross talk