Hi!

Few days ago I was lucky to establish calls between Chrome and SIP UA. Thanks to new rtpproxy developers! That was for audio only because many UAs lack for VP8 support. To verify a video I tried to involve Jitsi into the tests. Mediaproxy can't rewrite answer SDP from Jitsi. Probably the issue is related to SDP but I'm not sure to which part in particularly.

*Original offer SDP (ICE attributes are skipped) *

v=0 o=- 6784329718950523193 2 IN IP4 127.0.0.1 s=- t=0 0 a=group:BUNDLE audio video a=msid-semantic: WMS 0dKFIAlsVMexmIc0qjieYgfPDvBnSLG5lmpP m=audio 59996 RTP/SAVPF 111 103 104 0 8 107 106 105 13 126 c=IN IP4 10.xx.xx.xx a=rtcp:59996 IN IP4 10.xx.xx.xx .... a=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level a=sendrecv a=mid:audio a=rtcp-mux a=crypto:1 AES_CM_128_HMAC_SHA1_80 inline:VZhAArr96fxUtzvuNPpE+OSa09wchsmTD9pdrdBv a=rtpmap:111 opus/48000/2 a=fmtp:111 minptime=10 a=rtpmap:103 ISAC/16000 a=rtpmap:104 ISAC/32000 a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:107 CN/48000 a=rtpmap:106 CN/32000 a=rtpmap:105 CN/16000 a=rtpmap:13 CN/8000 a=rtpmap:126 telephone-event/8000 a=maxptime:60 a=ssrc:579751405 cname:n2gMzhLDYdqpWwP7 a=ssrc:579751405 msid:0dKFIAlsVMexmIc0qjieYgfPDvBnSLG5lmpP 0dKFIAlsVMexmIc0qjieYgfPDvBnSLG5lmpPa0 a=ssrc:579751405 mslabel:0dKFIAlsVMexmIc0qjieYgfPDvBnSLG5lmpP a=ssrc:579751405 label:0dKFIAlsVMexmIc0qjieYgfPDvBnSLG5lmpPa0 m=video 59996 RTP/SAVPF 100 116 117 c=IN IP4 10.xx.xx.xx a=rtcp:59996 IN IP4 10.xx.xx.xx ... a=extmap:2 urn:ietf:params:rtp-hdrext:toffset a=sendrecv a=mid:video a=rtcp-mux a=crypto:1 AES_CM_128_HMAC_SHA1_80 inline:VZhAArr96fxUtzvuNPpE+OSa09wchsmTD9pdrdBv a=rtpmap:100 VP8/90000 a=rtcp-fb:100 ccm fir a=rtcp-fb:100 nack a=rtcp-fb:100 goog-remb a=rtpmap:116 red/90000 a=rtpmap:117 ulpfec/90000 a=ssrc:1190198390 cname:n2gMzhLDYdqpWwP7 a=ssrc:1190198390 msid:0dKFIAlsVMexmIc0qjieYgfPDvBnSLG5lmpP 0dKFIAlsVMexmIc0qjieYgfPDvBnSLG5lmpPv0 a=ssrc:1190198390 mslabel:0dKFIAlsVMexmIc0qjieYgfPDvBnSLG5lmpP a=ssrc:1190198390 label:0dKFIAlsVMexmIc0qjieYgfPDvBnSLG5lmpPv0

*Original answer SDP*

v=0 o=user2 0 0 IN IP4 10.xx.xx.xx s=- c=IN IP4 10.xx.xx.xx t=0 0 m=audio 5052 RTP/AVP 0 8 126 a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:126 telephone-event/8000 m=video 5054 RTP/AVP 100 a=rtpmap:100 VP8/90000

*Mediaproxy logs* (for answer SDP)

mediaproxy-ng[14907]: Got valid command from 127.0.0.1:38310: answer .... mediaproxy-ng[14907]: [7dmpb0qdja07p87pa1ji - ] Got LOOKUP, but no usable callstreams found mediaproxy-ng[14907]: Error rewriting SDP mediaproxy-ng[14907]: Protocol error in packet from 127.0.0.1:38310: Error rewriting SDP:...

However the *audio calls work well*. Here's the answer SDP from Jitsi:

v=0 o=user2 0 0 IN IP4 10.xx.xx.xx s=- c=IN IP4 10.xx.xx.xx t=0 0 m=audio 5048 RTP/AVP 0 8 126 a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:126 telephone-event/8000

Comments and suggestions would be greatly appreciated.

regards, Alexey