Chapter 1 - Traditional Voice Versus Unified Voice

Question 1

Components of PSTN

Answer 1

Analog Telephone
Local Loop
CO Switch
Trunk
Private Switch
Digital Telephone

Question 2

Analog Signal

Answer 2

Method of signaling that uses properties of the transmission medium to convey sound characteristics

Question 3

Loop Start Signaling

Answer 3

Method of signaling that relies on connecting the tip and ring wires connecting to a device to complete the electrical circuit

Question 4

Ground Start Signaling

Answer 4

Method of signaling that relies on grounding wires connecting to a device to signal a new call

Question 5

Glare

Answer 5

A user picks up and connects unexpectedly to an incoming call

Question 6

Time-Division Multiplexing (TDM)

Answer 6

Method of transmitting multiple channels of voice or data over a single digital connection by sending data in specific time slots

Question 7

Channel Associated Signaling (CAS)

Answer 7

Method of digital signaling in which signaling in which signaling information is transmitted using same bandwidth as voice

Question 8

Common Channel Signaling (CCS)

Answer 8

Method of signaling in which information is transmitted using separate, dedicated signaling channel

Question 9

Robbed Bit Signaling (RBS)

Answer 9

Implementation of CAS that steals the 8th bit of every 6th frame of a digital T1 circuit for signaling information

Question 10

Q.931

Answer 10

signaling protocol used by ISDN CCS implementation

Question 11

Local Loop

Answer 11

PSTN link between customer premises and telco

Question 12

Private Branch Exchange (PBX)

Answer 12

System that allows a company to run an internal, private voice network. Used by larger companies

Question 13

Key System

Answer 13

System that allows a company to run a private, internal voice network. Used by smaller companies

Question 14

Signaling System 7 (SS7)

Answer 14

Protocol used within telephony service provider networks to provide inter-CO communication and call routing

Question 15

E.164

Answer 15

International numbering plan created by the ITU & adopted for use on the PSTN

Question 16

Quantization

Answer 16

Process of assigning analog signals a numeric value that can be transported over a digital network

Question 17

Nyquist Theorem

Answer 17

Method of converting analog signals into digital format by sampling twice the highest frequency of the audio

Question 18

Mean Opinion Score (MOS)

Answer 18

Subjective method of determining voice quality

Question 19

G.722

Answer 19

Uncompressed, moderate complexity codec with much better voice quality than G.711 while still consuming the same 64-kbps of bandwidth (typically)

Question 20

G.711

Answer 20

Uncompressed audio codec consuming 64-kbps of bandwidth

Question 21

G.726

Answer 21

Compressed audio codec consuming 32-kbps of bandwidth

Question 22

G.728

Answer 22

Compressed audio codec consuming 16-kbps of bandwidth

Question 23

G.729

Answer 23

Compressed audio codec consuming 8-kbps of bandwidth

Question 24

Real-Time Transport Protocol (RTP)

Answer 24

UDP-based protocol responsible for transporting audio packets. Uses random even numbered ports from 16,384 to 32,767 for communication

Question 25

Real-Time Transport Control Protocol (RTCP)

Answer 25

UDP-based protocol responsible for transporting audio statistics; uses random, odd-numbered ports from 16,384 to 32,767 for communication