Asterisk Sangoma Transcoding Operation

Once the sangoma transcoding configuration file is created by sngtc_cfg configurator we can start Asterisk and load codec_sangoma.so module from the Asterisk CLI.

 Asterisk CLI> module load codec_sangoma.so

An alternative for production systems is add the line load => codec_sangoma.so to Asterisk configuration modules.conf to get the codec module loaded at startup.

At this point the module will read the sangoma_codec.conf configuration and load the configured codec translators. Asterisk will make use of the translators as necesary.

WARNING: There is a bug in Asterisk that may lead to crashes when loading codecs if there are 2 different modules providing the same translation paths. See this bug report for more information:

http://issues.asterisk.org/view.php?id=17092

And also read the sample configuration comments in sng-tc-<version>/codec/asterisk/sangoma_codec.conf.sample to learn more about work-arounds in case you face the problem.

Once the module is loaded Asterisk will use the translation resources when needed. You can see which translators were registered by the Sangoma module using:

Asterisk CLI> sangoma show translators

You can monitor the usage of the translation resources using Asterisk CLI commands:

This command display all the transcoding sessions currently active along with some statistics per session like Tx/Rx packet counters and average Rx/Tx times in milliseconds.

Asterisk CLI> sangoma show transcoding sessions

This command display the lost RTP packets statistics for all sessions.

Asterisk CLI> sangoma show rtp statistics