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)