Behaviour when configuring a RTSP session with liveMediaServ

[jgg]

I add a comment just to help anybody in case he/she is interested in this issue.

As Remi said, VoD server seems to be a piece of VLC software which is programmed somehow independently from the rest of VLC functionalities and not in a very smart way. It can be noted how two rtsp.c files exist in the VLC source code: one in modules/stream_out and another in modules/misc, the latter being the one corresponding to the VoD server configured with VLM.

RTCP doesn't work properly in VoD configured with VLM because the server replies to the RTSP SETUP messages don't include the server ports in charge of RTP streams, as it has been noted in previous posts of this thread. These ports are selected AFTER the RTSP SETUP reply messages have already been sent, so I can't see any smart nor weird way to patch this apart from re-programming the VoD server.

This is indeed what Remi said, but I just wanted to know which was the real problem apart from the "crappy VoD server". Actually, this server neither supports RTP/RTSP interleaved mode (stream RTP/RTCP over the TCP connection used to configure the stream session with RTSP, this is the RTSP port) while other RTP servers do (i.e. Live Media Server). Although this is not an efficient streaming mode, it can cope with Firewall/NAT issues in many commercial routers. However, some of these implement RTSP Application Level Gateways which are capable to parse RTSP messages and dynamically open and close ports which are to be used in the RTP streaming session. In my experience (D-Link DIR-635), RTSP ALG doesn't work properly with Live Media RTSP server, although it announces the source and destination address and ports according to draft-ietf-mmusic-rtsp-nat-evaluation-01.

As said before, this is just a kind of answers compilation to what I've been experiencing with VLC regarding RTCP and NAT, obviously not pretending to be taken as a serious guide; just to spot some light in these issues. So, if I missed something or I unconsciously lied, just update the thread.