[Opalvoip-devel] FIR requests under SIP connection

[Alexander S. <ale...@gm...>]

   I found a problem with opal running SIP connection to Polycom 
videoconference server. H264 format was used for video.

It turns out that even under normal network Polycom RMX sometimes issue 
FIR request and it is ignored on the opal side as no I-Frame is being 
forced into stream.

Something like that popup in the log:

   0:09.316          RTP-2-control:15856  rtp_session.cxx(1554) 
RTP             Session 2, FIR from incorrect SSRC=0 (0x0)
   0:09.316          RTP-2-control:15856  rtp_session.cxx(1730) 
RTP             Session 2, received RFC5104 FIR: sn=0, last-sn=0, 
receiver SSRC=2279148435 (0x87d90b93), sender SSRC=0 (0x0)

Yes there is warning about zero SSRC and that is how frame looks in 
wireshark:

Frame 1461: 62 bytes on wire (496 bits), 62 bytes captured (496 bits) on 
interface 0
Ethernet II, Src: AccordVi_05:6d:79 (00:90:ca:05:6d:79), Dst: 
AsustekC_5c:53:7d (bc:ee:7b:5c:53:7d)
Internet Protocol Version 4, Src: 10.0.55.191, Dst: 10.0.55.197
User Datagram Protocol, Src Port: 49225, Dst Port: 5669
Real-time Transport Control Protocol (Payload-specific Feedback)
     [Stream setup by SDP (frame 6)]
     10.. .... = Version: RFC 1889 Version (2)
     ..0. .... = Padding: False
     ...0 0100 = RTCP Feedback message type (FMT): Full Intra Request 
(FIR) Command (4)
     Packet type: Payload-specific Feedback (206)
     Length: 4 (20 bytes)
     Sender SSRC: 0x00000000 (0)
     Media source SSRC: 0x8ebd4308 (2394768136)
     FIR 1
         SSRC: 0x87d90b93 (2279148435)
         Command Sequence Number: 0
         Reserved: 1
[RTCP frame length check: OK - 20 bytes]

Polycom RMX in it's turn halt video stream to opal until I-Frame is 
finally arrive.

As I remember FUR requests for same purpose works fine and force 
I-Frames into the stream. Is there support for FIR proccessing in opal?

Can be SSRC field of request be the cause of this request ignorance?