Codecs; Contents; Introduction - Avaya Nortel Communication Server 1000 Manual

Codecs

Contents

This section contains the following topics:
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Introduction

The IP Phones and Voice Gateway Media Cards support different codecs
and codec parameters with different compression rates and audio
quality. The CS 1000 system selects the appropriate codecs based on
user-configurable parameters.
For instance, an IP Phone-to-IP Phone call in the same zone within a LAN
can be set up using G.711 at 64 kb/s. For an IP Phone-to-IP Phone call over
a WAN, the call can be set up using G.729A or G.729AB at 8 kb/s. These
data rates and the Voice Gateway Channel Server on the Voice Gateway
Media Card are for the voice stream only. Packet overhead is not included.
Predefined codec table
The Line Terminal Proxy Server (LTPS) and the Voice Gateway Channel
Server on the Voice Gateway Media Card have a predefined table of codec
option sets that can be supported.
The first entry in the table has the highest quality audio (BQ = Best Quality)
and requires the largest amount of bandwidth. The last entry requires the
least amount of bandwidth (BB = Best Bandwidth) with lower voice quality.
Copyright © 2003–2008, Nortel Networks
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"Introduction" (page 215)
"Codec configuration" (page 217)
"Codec registration" (page 219)
"Codec negotiation" (page 222)
"Codec selection" (page 224)
Nortel Communication Server 1000
IP Line Fundamentals
NN43100-500 02.02 Standard
Release 5.5 4 February 2008
215