I have two FreePBX servers. The second one was cloned from first some time ago. But from that time their configuration could be changed.
On both servers on for all endpoints DTMF is set to SIP INFO mode.
On one server when client A send SIP INFO with DTMF then server stop send RTP stream to client B with original SSRC and start sending new stream with another SSRC. After about 300-500 ms it stop new RTP stream and resume sending old stream with old SSRC.
The second server behaves differently. It just continue send RTP stream with original SSRC.
I compared configuration of both servers in their FreePBX web interfaces and didn’t find any differences.
I don’t know which behavior is right and where is is configured.
Also I don’t know what is the right way to handle this additional temporary stream (we develop SIP client). Should it be ignored or played?