SIP Phone Codec A to SIP Phone Codec B without Transcoding


I would like to do the following

  • SIP Phone A has G711u and G729 available with G711u as default codec and has ulaw and g729 available via Asterisk allowed command.
  • SIP Phone B has G729 and G711u available but with G729 as default codec and only codec allowed via Asterisk.
  • Both are on the same Asterisk system
  • Would like to have SIP Phone A calling out via G711u, to try to call SIP Phone B and have SIP Phone A to switch to G729.

Problem that is happening right now

  • When SIP phone A calls SIP phone B, Asterisk Transcodes G711u to G729 and causes choppy audio.

What we want

  • SIP Phone A who calls out via G711u has to convert its internal codec to G729 to be able to reinvite g729 with SIP Phone B.

Is there any way to Reinvite with Renegociate Codecs ?