I have a SIP Trunk, where I receive an INVITE with SDP info like this
...
v=0
o=BroadWorks 189068020 1 IN IP4 192.168.0.100
s=-
c=IN IP4 192.168.0.100
t=0 0
m=audio 50106 RTP/AVP 116 9 118 8 0 18 111 110
b=AS:137
b=RS:0
b=RR:0
a=rtpmap:116 AMR-WB/16000/1
a=fmtp:116 mode-change-capability=2; max-red=220
a=rtpmap:9 G722/8000
a=rtpmap:118 AMR/8000/1
a=fmtp:118 mode-change-capability=2; max-red=220
a=rtpmap:8 PCMA/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:18 G729/8000
a=rtpmap:111 telephone-event/16000
a=fmtp:111 0-15
a=rtpmap:110 telephone-event/8000
a=fmtp:110 0-15
a=sendrecv
a=maxptime:40
a=ptime:20
...
The SBC reply with
...
v=0
o=- 4294967295 1 IN IP4 192.168.0.100
s=-
c=IN IP4 192.168.0.100
t=0 0
m=audio 16856 RTP/AVP 8 0 111 110
c=IN IP4 192.168.0.100
a=rtpmap:8 PCMA/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:111 telephone-event/16000
a=fmtp:111 0-15
a=rtpmap:110 telephone-event/8000
a=fmtp:110 0-15
...
The SIP Trunk send a BYE after a 2 seconds, and I expect is because the rtpmap:111 is in the response
The question is if it is allowed to have both rtpmap:111 and rtpmap:110 in this reply according to the RFC...
