Coders And Profiles; Configuring Coders - AudioCodes Mediant 2000 User Manual

SIP User's Manual
16

Coders and Profiles

This section describes configuration of the coders and SIP profiles parameters.
16.1

Configuring Coders

The Coders page allows you to configure up to 10 voice coders for the device to use. Each
coder can be configured with packetization time (ptime), rate, payload type, and silence
suppression.
The first coder in the table has the highest priority and is used by the device whenever
possible. If the remote side cannot use the first coder, the device attempts to use the next
coder in the table, and so on.
Notes:
Version 6.4
•
For a list of supported coders and for configuring coders using the ini file,
refer to the ini file parameter table CodersGroup, described in
''Configuration Parameters Reference'' on page 409.
•
Each voice coder can appear only once in the table.
•
If packetization time and/or rate are not specified, the default value is
applied.
•
Only the packetization time of the first coder in the coder list is declared
in INVITE/200 OK SDP, even if multiple coders are defined.
•
The device always uses the packetization time requested by the remote
side for sending RTP packets.
•
For G.729, it's also possible to select silence suppression without
adaptations.
•
If the coder G.729 is selected with silence suppression is disabled, the
device includes 'annexb=no' in the SDP of the relevant SIP messages. If
silence suppression is enabled or set to 'Enable w/o Adaptations',
'annexb=yes' is included. An exception to this logic is when the remote
gateway is a Cisco device (IsCiscoSCEMode).
•
For defining groups of coders, which can be assigned to Tel and IP
Profiles, see ''Configuring Coder Groups'' on page 200.
•
For information on V.152 and implementation of T.38 and VBD coders,
see ''Supporting V.152 Implementation'' on page 141.
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16. Coders and Profiles
November 2011