Appendix C: Glossary and Acronyms

HDLC High-Level Data Link Control

A bit-oriented synchronous data link layer protocol developed by the International Organization for Standardization (ISO).

IAX Inter-Asterisk eXchange

The native VoIP protocol used by Asterisk. It is an IETF standard used to enable VoIP connections between Asterisk servers, and between servers and clients that also use the IAX protocol.

iLBC internet Low Bitrate Codec

A free speech codec used for voice over IP. It is designed for narrow band speech with a payload bitrate of 13.33 kbps (frame length = 30ms) and 15.2 kbps (frame length = 20ms).

ILEC Incumbent Local Exchange Carrier

The LECs that were the original carriers in the market prior to the entry of competition and therefore have the dominant position in the market.

interface

A point of contact between two systems, networks, or devices.

ISO International Standards Organization

IVR Interactive Voice Menu

An interactive technology that allows a telephone system to detect voice and keypad input.

Digium, Inc.

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