Hi All, Consider the below SDP from Polycom SIP endpoint . The rtpmap and fmtp uses same payload number 96 for h264 and h263 video codec. According to RFC standards of RTP and SDP, same payload numbers can be given when it is in the scope of media line. I mean audio and video codecs can have same dynamic payload numbers.
Is it allowed to keep same dynamic payload numbers for different video codecs ? How the SIP UA should behave in this scenario ? Does it accept the first video codec and neglect the other video codec with same payload number or does it establish audio only session if audio + video stream is sent in SDP. v=0 o=POLYCOM 0 33 IN IP4 10.19.16.74 s=- c=IN IP4 10.19.16.74 b=AS:1024 t=0 0 m=audio 49678 RTP/AVP 9 0 8 115 102 15 18 101 a=rtpmap:9 G722/8000 a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:115 G7221/32000 a=fmtp:115 bitrate=48000 a=rtpmap:102 G7221/16000 a=fmtp:102 bitrate=32000 a=rtpmap:15 G728/8000 a=rtpmap:18 G729/8000 a=fmtp:18 annexb=no a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-15 a=sendrecv m=video 49680 RTP/AVP 116 96 110 96 34 111 31 b=TIAS:1024000 a=rtpmap:116 vnd.polycom.lpr/9000 a=fmtp:116 V=1;minPP=0;PP=150;RS=52;RP=10;PS=1400 a=rtpmap:96 H264/90000 a=fmtp:96 profile-level-id=428020; max-mbps=244800; max-fs=8160; sar=13 a=rtpmap:110 H264/90000 a=fmtp:110 profile-level-id=428020; packetization-mode=1; max-mbps=244800; max-fs=8160; sar=13 a=rtpmap:96 H263-1998/90000 a=fmtp:96 CIF4=2;CIF=1;QCIF=1;SQCIF=1;CUSTOM=352,240,1;CUSTOM=704,480,2 a=rtpmap:34 H263/90000 a=fmtp:34 CIF4=2;CIF=1;QCIF=1;SQCIF=1 a=rtpmap:111 H264/90000 a=fmtp:111 profile-level-id=640020; packetization-mode=1; max-mbps=244800; max-fs=8160; sar=13 a=rtpmap:31 H261/90000 a=fmtp:31 CIF=1;QCIF=1 a=sendrecv a=rtcp-fb:* ccm fir m=application 49684 RTP/AVP 100 a=rtpmap:100 H224/4800 a=sendrecv Best Regards, Gaurav This is confidential Ittiam property. _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
