O'Reilly logo

VoIP and Unified Communications: Internet Telephony and the Future Voice Network by William A. Flanagan

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

12

APPENDIXES

12.1 ACRONYMS AND DEFINITIONS

Some terms are defined at the locations referenced in the Index.

0x

Indication that the following characters are a hexadecimal expression.

5ESS

Class 5 Electronic Switching System, CO voice switch that serves end users.

AB

Two signaling bits in T-1 CAS when using a superframe.

ABCD

Four signaling bits in T-1 CAS when using the extended superframe.

ABNF

Augmented Backus—Naur Form.

AC

Area Code, in telephone number.

ACD

Automatic Call Distributor, PBX function or machine to spread calls among phones.

ACELP

Adaptive CELP.

ACF

Admission Confirm.

ACK

ACKnowledge, message type to confirm receipt of request or action taken.

ADC

Analog-to-Digital Converter, first step to encode voice as a digital stream.

address

IP address of a host; MAC, DLCI, or other L2 destination or source identifier; cf socket.

ADPCM

Adaptive Differential Pulse Code Modulation, form of compressed voice encoding.

AH

Authentication Header, form of IPsec that digitally signs but doesn't encrypt.

A-Law

Form of PCM companding used with E-1 links.

ALF

Application Level Framing.

ALG

Application Layer Gateway.

ALI

Automatic Location Information (Identifier), geographic indication associated with a telephone, landline or cellular, delivered to a PSAP with E911 call; kept in an ALI database.

AN

Acknowledgment Number, associated with an octet in a TCP stream or a packet.

analog

Can take on any value to represent sound; see digital.

ANI

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required