Optimization Testing: experiment PJSIP Audio Switchboard in place of Conference Bridge

[fpietrosanti]

As our conference bridge shouldn't be doing resampling or transcoding of any kind assuming we have the same audio codec of VoIP Provider and on Modem Server, we may just enable the Audio Switchboard of PJSIP designed to replace Conference Bridge by just doing RTP packet forwarding between the legs without Audio Latency.

See Audio Latency reduction FAQ https://trac.pjsip.org/repos/wiki/FAQ#audio-latency

"If you don't need conferencing, you may want to consider replacing the conference bridge with the audio switchboard which does very minimum buffering to the audio. You will loose conferencing feature, but as a bonus this will lower CPU usage too.

To use the audio switchboard, declare this in your config_site.h:

#define PJMEDIA_CONF_USE_SWITCH_BOARD 1"