[sr-dev] mediaproxy-ng failed to rewrite sdp from jssip ws client

[Juha Heinanen]

Peter Dunkley writes:

> You need to use the '-' and '+' flags for adding/removing ICE
> candidates.

i tried by calling rtpproxy_offer(co1sp+r) on invite from jssip.  that
caused replacement of jssip candidates with mediaproxy-ng candidates and
callee got this kind of sdp:

v=0.
o=- 5710554713508805259 2 IN IP4 192.98.102.30.
s=-.
t=0 0.
a=group:BUNDLE audio video.
a=msid-semantic: WMS LgzU4F96QsED6P60D56isMPuYgV33LrakdUo.
a=ice-lite.
m=audio 50016 RTP/AVP 111 103 104 0 8 107 106 105 13 126.
c=IN IP4 192.98.102.30.
a=fingerprint:sha-256 D1:B4:83:5B:FD:14:CD:04:02:75:AE:66:57:5D:4C:D6:BE:2A:43:0E:CE:37:7C:73:F5:A9:F3:96:B3:97:C2:1C.
a=mid:audio.
a=sendrecv.
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:1172642791 cname:vy8KI4LJpDH09wA9.
a=ssrc:1172642791 msid:LgzU4F96QsED6P60D56isMPuYgV33LrakdUo LgzU4F96QsED6P60D56isMPuYgV33LrakdUoa0.
a=ssrc:1172642791 mslabel:LgzU4F96QsED6P60D56isMPuYgV33LrakdUo.
a=ssrc:1172642791 label:LgzU4F96QsED6P60D56isMPuYgV33LrakdUoa0.
a=rtcp:50017.
a=ice-ufrag:tlocltly.
a=ice-pwd:0zaQ50urFrM3pmFDJES09yQATfMf.
a=candidate:P7f12vpGOKrMUtvG 1 UDP 2130706432 192.98.102.30 50016 typ host.
a=candidate:P7f12vpGOKrMUtvG 2 UDP 2130706431 192.98.102.30 50017 typ host.
m=video 50016 RTP/AVP 100 116 117.
c=IN IP4 192.98.102.30.
a=fingerprint:sha-256 D1:B4:83:5B:FD:14:CD:04:02:75:AE:66:57:5D:4C:D6:BE:2A:43:0E:CE:37:7C:73:F5:A9:F3:96:B3:97:C2:1C.
a=mid:video.
a=sendrecv.
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:2673317016 cname:vy8KI4LJpDH09wA9.
a=ssrc:2673317016 msid:LgzU4F96QsED6P60D56isMPuYgV33LrakdUo LgzU4F96QsED6P60D56isMPuYgV33LrakdUov0.
a=ssrc:2673317016 mslabel:LgzU4F96QsED6P60D56isMPuYgV33LrakdUo.
a=ssrc:2673317016 label:LgzU4F96QsED6P60D56isMPuYgV33LrakdUov0.
a=rtcp:50017.
a=ice-ufrag:tlocltly.
a=ice-pwd:0zaQ50urFrM3pmFDJES09yQATfMf.
a=candidate:P7f12vpGOKrMUtvG 1 UDP 2130706432 192.98.102.30 50016 typ host.
a=candidate:P7f12vpGOKrMUtvG 2 UDP 2130706431 192.192.98.102.30 50017 typ host.

since callee does not support ice, it replies with this kind of sdp:

v=0.
o=- 4194830220 1645980272 IN IP4 87.95.166.173.
s=-.
c=IN IP4 87.95.166.173.
t=0 0.
a=tool:baresip 0.4.6.
m=audio 10302 RTP/AVP 0 8 126.
b=AS:125.
a=rtpmap:0 PCMU/8000.
a=rtpmap:8 PCMA/8000.
a=rtpmap:126 telephone-event/8000.
a=fmtp:126 0-15.
a=sendrecv.
a=label:1.
a=ptime:20.
m=video 0 RTP/AVP 0.

i then call rtpproxy_answer(co2SP+r) on it in order to add mediaproxy-ng
candidates to the reply going to jssip, but i get the error:

Oct 25 16:32:10 rautu mediaproxy-ng[3966]: Got valid command from 127.0.0.1:36564: answer - { "sdp": "v=0#015#012o=- 4194830220 1645980272 IN IP4 87.95.166.173#015#012s=-#015#012c=IN IP4 87.95.166.173#015#012t=0 0#015#012a=tool:baresip 0.4.6#015#012m=audio 10302 RTP/AVP 0 8 126#015#012b=AS:125#015#012a=rtpmap:0 PCMU/8000#015#012a=rtpmap:8 PCMA/8000#015#012a=rtpmap:126 telephone-event/8000#015#012a=fmtp:126 0-15#015#012a=sendrecv#015#012a=label:1#015#012a=ptime:20#015#012m=video 0 RTP/AVP 0#015#012", "ICE": "force", "flags": [ "trust-address" ], "replace": [ "session-connection", "origin" ], "transport-protocol": "RTP/SAVPF", "call-id": "cmpfetg0521rvdrho77o", "via-branch": "z9hG4bK2081108", "received-from": [ "IP4", "192.98.102.30" ], "from-tag": "717fgt9qhe", "to-tag": "dcbb68b152366222", "command": "answer" }
Oct 25 16:32:10 rautu mediaproxy-ng[3966]: [cmpfetg0521rvdrho77o - z9hG4bK2081108] Got LOOKUP, but no usable callstreams found
Oct 25 16:32:10 rautu mediaproxy-ng[3966]: Error rewriting SDP
Oct 25 16:32:10 rautu mediaproxy-ng[3966]: Protocol error in packet from 127.0.0.1:36564: Error rewriting SDP [d3:sdp304:v=0#015#012o=- 4194830220 1645980272 IN IP4 87.95.166.173#015#012s=-#015#012c=IN IP4 87.95.166.173#015#012t=0 0#015#012a=tool:baresip 0.4.6#015#012m=audio 10302 RTP/AVP 0 8 126#015#012b=AS:125#015#012a=rtpmap:0 PCMU/8000#015#012a=rtpmap:8 PCMA/8000#015#012a=rtpmap:126 telephone-event/8000#015#012a=fmtp:126 0-15#015#012a=sendrecv#015#012a=label:1#015#012a=ptime:20#015#012m=video 0 RTP/AVP 0#015#0123:ICE5:force5:flagsl13:trust-addresse7:replacel18:session-connection6:origine18:transport-protocol9:RTP/SAVPF7:call-id20:cmpfetg0521rvdrho77o10:via-branch14:z9hG4bK208110813:received-froml3:IP413:192.98.102.30e8:from-tag10:717fgt9qhe6:to-tag16:dcbb68b1523662227:command6:answere]
Oct 25 16:32:10 rautu mediaproxy-ng[3966]: Returning to SIP proxy: d6:result5:error12:error-reason19:Error rewriting SDPe
Oct 25 16:32:10 rautu /usr/sbin/sip-proxy[1364]: ERROR: rtpproxy-ng [rtpproxy.c:1348]: rtpp_function_call(): proxy replied with error: Error rewriting SDP

how could this error be related to +/- parameters?

-- juha