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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