[vlc-devel] Bounty tasks details request

[Gilles Chanteperdrix]

On 12/22/2013 08:43 PM, Rémi Denis-Courmont wrote:
> Le dimanche 22 décembre 2013, 20:14:32 Gilles Chanteperdrix a écrit :
>> I do not rely on that. I use that information if I get it. The problem
>> with multiple SETUP behind the same NAT IP only exists if the server
>> sends the same stream with the same SSRC to multiple clients,
> 
> The client is only supposed to send RTCP-RR to the RTCP port of the pair, 
> which could be used as a strong, albeit insecure, hint of the RTCP destination 
> port number. There is no way to detect the RTP destination port of an off-the-
> shelve RTSP client behind a stateful NAT.
> 
> Even then, this does not really work since, from the protocol perspective, the 
> server will start sendind RTP/RTCP before the client can.

vlc sends a packet to the server RTP port between SETUP and PLAY. So,
before the server starts streaming. Recent versions of vlc send also a
dummy RTCP packet between SETUP and PLAY, this avoids having to wait for
the first RR before SR can pass through the NAT.


-- 
                                                                Gilles.