Coders And Profiles; Configuring Coder Groups - AudioCodes Mediant 4000 SBC User Manual

User's Manual
19

Coders and Profiles

This section describes configuration of the coders and SIP profiles parameters.
19.1

Configuring Coder Groups

The Coder Groups table lets you configure up to 21 Coder Groups. The Coder Group
determines the audio (voice) coders used for calls. Each Coder Group can include up to 10
coders, where the packetization time (ptime), bit rate, payload type, and silence
suppression can be configured per coder. The first coder in the Coder Group 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 Coder Group, and so on.
The Coder Groups table provides a pre-defined Coder Group (index 0) that is configured
with the G.711 A-law coder. If no other Coder Groups are configured, the default Coder
Group (which you can modify) is used for all calls. Alternatively, if you want to use specific
coders or coder settings (e.g., packetization time) for different calls (entities), you need to
configure a Coder Group for each entity and then assign each Coder Group to the IP
Profile (see ''Configuring IP Profiles'' on page 384) associated with the entity (IP Group). If
an IP Group is not associated with a Coder Group, the default Coder Group is used.
You can also use Coder Groups for audio coder transcoding of SBC calls. If two SIP
entities need to communicate, but one does not support a coder required by the other, the
device can add the required coder to the SDP offer. The added coder is referred to as an
extension coder. For more information on extension coders, see Coder Transcoding on
page 429.
To apply a Coder Group for transcoding to a SIP entity:
1. Configure a Coder Group in the Coder Groups table (see description below).
2. In the IP Profile associated with the SIP entity (see Configuring IP Profiles on page
384):
•
Assign the Coder Group (using the IpProfile_SBCExtensionCodersGroupName
parameter).
•
Enable the use of the Coder Group for transcoding (by configuring the
IpProfile_SBCAllowedCodersMode parameter to Restriction or Restriction and
Preference).
The following procedure describes how to configure the Coder Groups table through the
Web interface. You can also configure it through ini file (AudioCodersGroups and
AudioCoders) or CLI (configure voip > coders-and-profiles audio-coders-groups).
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19. Coders and Profiles
Mediant 4000 SBC