The Media Server supports a set of audio codecs. The following panel allows you to control how these codecs are used:
There are two Priority settings for each codec - the primary and the secondary one.
When a Media Server composes an initial offer, the codecs are listed sorted by their primary and secondary priority values. Codecs with the primary Priority set to Inactive or to 1 are not listed in the initial offer.
When a Media Server composes an answer or a non-initial offer, i.e. when the audio codecs supported by the peer are known, only the codecs supported by the peer are listed. Codecs with the primary Priority set to Inactive are not listed in answers and non-initial offers. The Media Server codecs are listed sorted by their primary Priority values. If several Media Server codecs have the same primary Priority values, they are listed in the same order as they were listed in the peer's offer.
Note: the set of supported codecs depends on the platform CommuniGate Pro is running on.
Compressing codecs (such as G.729) require a lot of CPU resources. You may want to offload coding-encoding operations to separate Transcoder servers:
If the Usage setting is set to Transcoder, the Media Server tries to create a transcoder channel on one of the listed Transcoder servers. The peer is instructed to exchange media with the created transcoder channel, while the transcoder channel exchanges media with the CommuniGate Pro Media Server using the PCM (G.711) codec.
Transcoder servers are used in a round-robin manner. If a Transcoder refuses to create a transcoder channel, and there are more than 2 servers specified, the next server is contacted.
The CommuniGate Pro Server software or special CommuniGate Pro Transcoder software can be used to implement Transcoder servers.