User's Manual

The list of codecs specified in the Device Configuration file determines the list of codecs that
are available for selection on the IP Deskphone.
Two fields in the device configuration file, G729_ENABLE_ANNEXB and
G723_ENABLE_ANNEXA are used to enable or disable AnnexB and AnnexA support by
G.729 and G.723 codecs, respectively. These flags can have the following values: YES, NO
(No is the default value).
Important:
If codecs are not specified, the default list used by the current version of the IP Deskphone
is PCMU, PCMA, G.729.
To stop the IP Deskphone from using a specific codec, you must change its entry in the Device
Configuration file to a different codec, and then clear the value of the original specific codec,
which disables the codec entry. If you remove all codecs from the allowed list, the IP Deskphone
resets to the default list of codecs.
Important:
To reset the phone to the default list of codecs, it is necessary to remove the values against
each AUDIO_CODECx item in the Device Configuration file.
For example:
AUDIO_CODEC1 PCMA standard a-law
AUDIO_CODEC2 PCMU standard u-law
AUDIO_CODEC3 G729 729 codec
AUDIO_CODEC4 G722 wideband codec
AUDIO_CODEC5 G723 high-compression codec
would become
AUDIO_CODEC1
AUDIO_CODEC2
AUDIO_CODEC3
AUDIO_CODEC4
AUDIO_CODEC5
If the ordered list of codecs is small and no matching codec is found during negotiations, the
call drops, as the audio stream cannot be established. For backward compatibility with SIP
Firmware Release 1.X, the Device Configuration file supports the DEF_AUDIO_QUALITY
parameter as long as no codec is allowed using the parameter AUDIO_CODECN, in which
case the DEF_AUDIO_QUALITY parameter is ignored and has no effect.
Specifying the DEF_AUDIO_QUALITY as High or Medium has the same effect as omitting the
parameter altogether and without specifying codec through the parameters.
If set to Low, then the list of default codecs is reversed before being sent in the SDP
negotiations. When you do not provide a text description in the Device Configuration file, the
application uses the default text description from the language file.
Codec preference through the Device Configuration file
SIP Software for Avaya 1100 Series IP Deskphones-Administration November 2012 247