Terms - Blake - LE 1

Question 1

method of providing high-speed data transmission on twisted-pair telephone loops by
using high-frequency carriers

Answer 1

Asymmetrical Digital Subscriber Line (ADSL)

Question 2

in ISDN, channels that carry subscriber communication (voice or data or both)

Answer 2

B (bearer) channels

Question 3

use of bits that normally carry payload information for

other purposes, such as controlling the communication system

Answer 3

bit robbing

Question 4

addition of bits to a bitstream to compensate for timing

variations

Answer 4

bit stuffing

Question 5

failure to connect a telephone call because of lack of

system capacity

Answer 5

call blocking

Question 6

switch in a telephone system that connects to local

subscriber lines

Answer 6

central office

Question 7

communication system in which a dedicated channel is set up between parties for the duration of the communication

Answer 7

circuit-switched network

Question 8

use of a separate signaling channel in a

telephone system, so that voice channels do not have to carry signaling information

Answer 8

common-channel signaling

Question 9

interference between two signals multiplexed into the same channel

Answer 9

crosstalk

Question 10

in ISDN, a communication channel used for setting up

calls and not for user communication

Answer 10

D (data) channel

Question 11

signaling using combinations

of two audio tones transmitted on the voice channel

Answer 11

dual-tone multi-frequency (DTMF) dialing

Question 12

use of optical fiber for telephone connections to

individual customers

Answer 12

fiber-in-the-loop (FITL)

Question 13

a specialized transformer (or its electronic equivalent) that
allows telephone voice signals to travel in both directions
simultaneously on a single twisted-pair loop

Answer 13

hybrid coil

Question 14

control signals sent in a voice channel at voice frequencies

Answer 14

in-band signals

Question 15

control signals using the same channel as a voice signal

Answer 15

in-channel signals

Question 16

telephone system using
digital local loops for both voice and data, with the codec in the
telephone equipment

Answer 16

integrated services digital network (ISDN)

Question 17

addition of bits to a digital signal to compensate for

differences in clock rates; informally known as bit stuffing

Answer 17

justification

Question 18

in a telephone system, the area

controlled by one central office switch

Answer 18

local access and transport area (LATA)

Question 19

a small data network, usually confined to a building

or cluster of buildings

Answer 19

LAN or local area network

Question 20

in a telephone system, the wiring from the central office to an individual customer

Answer 20

local loop

Question 21

in telephone signaling, a control signal that is outside the

voice frequency range

Answer 21

out-of-band

Question 22

a communication system that works using data
divided into relatively short transmissions called packets; these are routed through the system without requiring a long-term connection between sender and receiver

Answer 22

packet-switched network

Question 23

place where one telephone network connects to

another

Answer 23

point of presence (POP)

Question 24

small telephone switch located on customer premises

Answer 24

private branch exchange (PBX)

Question 25

the ordinary public wireline

phone system

Answer 25

public switched telephone system (PSTN)

Question 26

in telephony, a signal generated at the central office and

sent to the originating telephone to indicate that the destination telephone is ringing

Answer 26

ringback signal

Question 27

in telephony, the presence in the receiver of sounds picked up by the transmitter of the same telephone

Answer 27

sidetone

Question 28

system used in telephony which transmits
all call setup information on a packet-data network that is separate from the voice channels used for telephone conversations

Answer 28

signaling system seven (SS7)

Question 29

telephone switch that connects only to other switches,

and not to individual customers

Answer 29

tandem office

Question 30

transmission line carrying many signals, either on multiple

pairs or multiplexed together on a single twisted-pair, coaxial cable, or optical fiber

Answer 30

trunk lines

Question 31

The single twisted-pair local loop is required to carry both sides of the conversation simultaneously, providing full-duplex communication.

Answer 31

Two-wire System

Question 32

The rest of the network uses separate transmission

paths for each direction, a topology called a ___

Answer 32

four-wire system

Question 33

Deliberately unbalancing the circuit allows a small portion of the transmitter signal to reach the receiver, creating a ___ that lets the user know
the line is active and hear what is being transmitted.

Answer 33

sidetone

Question 34

results in a very slight degradation of voice signal quality; for instance, the
signal-to-noise ratio is reduced by about two decibels

Answer 34

bit robbing

Question 35

extra bits called ____ which
are added during multiplexing to compensate for differences between the clock rates of the tributaries and the multiplexer

Answer 35

stuff bits