Hi Andy - I think: 1 - more not non-compliant, if you see what I mean; 2 - probably, given the change in SSRC 3 - nor could I 4 - I suspect that accepting packets with any sequence number immediately after a change of SSRC should be safe, and it looks like a reasonably straightforward change to handle_rfc2833 to cope with this situation. --Dave On Mon, Jan 18, 2021 at 12:02 PM Andy Newlands <andynewlands@gmail.com> wrote:
Hi,
A 3rd-party is sending each RFC2833 DTMF digit with a new SSRC and starts the packet sequence numbering at ZERO for each new digit.
I can see, in switch_rtp.c: handle_rfc2833(), that FS makes a note (in the session) of the last DTMF packet it processed, then drops any subsequent packets with a sequence number less than that.
My questions are:
1. Is the remote-party compliant with relevant RFCs when they set a new SSRC for each DTMF digit? 2. Is the remote party compliant with relevant RFCs when they re-start packet sequence numbers from 0 for each DTMF digit? 3. Looking at the source for handle_rfc2833(), I can't see any setting which could be used to force FS to 'tolerate' the above behaviour 4. If I alter handle_rfc2833(), to cope with that behaviour, am I likely to run into problems with other remote systems (E.G. possibly ending up with duplicate digits)
Thanks,
Andy _________________________________________________________________________
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