Chapter 16

Question 1

are communications networks that cover broad geographic areas that still frequently use phone companies (service providers) along with their circuit-switched networks to connect LANs together. p576

Answer 1

WANs

Question 2

WAN service type from a provider typically use: p577

Answer 2

Customer premises equipment (CPE)
 Channel service unit/data service unit (CSU/DSU) 
Demarcation point 
Smart Jack/NIU
Copper Line Drivers/Repeaters
Local loop 
Central office (CO)
Toll network

Question 3

is a Layer 1 device that connects your serial ports on your router to the provider’s network and connects directly to the demarcation point (demark) or location. p577

Answer 3

Channel service unit/data service unit (CSU/DSU)

Question 4

What is a Demarcation point p578

Answer 4

The demarc is the precise spot where the service provider’s (local exchange carrier) responsibility ends and the CPE begins. It’s generally a device in a telecommunications closet owned and installed by the telecommunications company (telco).

Question 5

What is a Local loop. p579

Answer 5

A cable consisting of a pair of copper wires called the local loop connects the demarc to the closest switching office known as a central office (CO).

Question 6

What is a Central office (CO).p 579

Answer 6

A phone company building that connects the customer’s network to the provider’s switching network. Good to know is that a CO is sometimes referred to as a point of presence (POP).

Question 7

What is a Toll network. p579

Answer 7

The toll network is a trunk line inside a WAN provider’s network. This network is a collection of switches and facilities owned by the ISP.

Question 8

The portion of the PSTN that runs from your house to the rest of the world is known as. p579

Answer 8

plain old telephone service (POTS)

Question 9

Two key concepts to keep in mind about PSTN are. p579

Answer 9

public and switched

Question 10

basically means that, for a fee, anyone can lease the use of the network without having to deal with running any cabling. p579

Answer 10

Public

Question 11

is a pre-established WAN communications path that goes from the CPE through the DCE switch and then over to the CPE of the remote site. p580

Answer 11

dedicated leased line

Question 12

uses dial-up modems or ISDN and is used for low-bandwidth data transfers. p581

Answer 12

Circuit switching

Question 13

can be thought of as a network that’s designed to look like a leased line yet charges you more like circuit switching does. p581

Answer 13

Packet switching

Question 14

What are some WAN connection types. p580-81

Answer 14

Packet switching
Circuit switching
dedicated leased line

Question 15

Modems are required to _______________ the signal, which means translating the analog signal our ears hear into a digital stream for transfer across a digital network. p582

Answer 15

modulate/demodulate

Question 16

The basic, first level in bandwidth or speed for leased lines that provide synchronous connections between sites is known as the. p582

Answer 16

T1 line. It serves up 24 Digital Signal 0 (DS0), 64Kbps channels in our country, Japan, and South Korea

Question 17

what is the maximum speed for T1. p583

Answer 17

1.544Mbps

Question 18

what is the maximum speed for T1C

Answer 18

3.152Mbps

Question 19

what is the maximum speed for T2

Answer 19

6.312Mbps

Question 20

what is the maximum speed for T3

Answer 20

44.736Mbps

Question 21

what is the maximum speed forT4

Answer 21

274.176Mbps

Question 22

Another aspect of WAN technologies that can have a big effect on the speed, bandwidth, and the volume of data that can be transferred is the type of ____________.p584

Answer 22

Transmission Media

Question 23

In the U.S, the standard for synchronous data transmission on optical fiber is called. p585

Answer 23

Synchronous Optical Network (SONET)

Question 24

SONET defines a base data rate, or throughput, of 51.84Mbps, and multiples of this rate are known as. p585

Answer 24

optical carrier (OC)

Question 25

The data rate for OC-1

Answer 25

51.84Mbps

Question 26

The data rate for OC-3

Answer 26

155.52Mbps

Question 27

The data rate for OC-12

Answer 27

622.08Mbps

Question 28

The data rate for OC-48

Answer 28

2.488Gbps

Question 29

The data rate for OC-192

Answer 29

9.953Gbps

Question 30

Is a technology that multiplexes several optical carriers on a single optical fiber by using different wavelengths. p585

Answer 30

Wavelength Division Multiplexing (WDM)

Question 31

Multiplexes within a specific band allowing for the use of erbium-doped fiber amplifiers (EDFA) that boost the signal. p585

Answer 31

Dense Wavelength Division Multiplexing

Question 32

is a technology for transmitting digital and sometimes even analog signals between two locations on a line-of-sight radio path through the atmosphere. p587

Answer 32

Microwave radio relay

Question 33

is an artificial satellite stationed in space for telecommunications purposes.p587

Answer 33

communications satellite (comsat)

Question 34

It was typically used to interconnect local-exchange carrier systems and to carry high-speed corporate data links and voice channels using T1 lines. p590

Answer 34

High bit-rate digital subscriber line (HDSL)

Question 35

It’s typically used by small to medium-sized businesses that don’t require the higher performance of a leased line for connecting to a server. p590

Answer 35

Symmetric digital subscriber line (SDSL)

Question 36

is capable of supporting high-bandwidth applications like HDTV, telephone services like the popular Voice over IP (VoIP), as well as general Internet access over a single connection. p590

Answer 36

Very high Bit-rate digital subscriber line (VDSL)

Question 37

This makes downloading graphics, audio, video, and data files from any remote computer a snap. p591

Answer 37

Asymmetric digital subscriber line (ADSL)