Re: [MMUSIC] Question about RTSP proxy

["Y.J. Gu" <guyingjie at huawei.com>]

Hi Remi, see in line please.

Regards

Yingjie Gu

 

> -----Original Message-----
> From: Rémi Denis-Courmont [mailto:remi at remlab.net] 
> Sent: Wednesday, August 12, 2009 2:50 PM
> To: Y.J. Gu
> Cc: mmusic at ietf.org
> Subject: Re: [MMUSIC] Question about RTSP proxy
> 
> 
>     Hello,
> 
> On Tue, 11 Aug 2009 14:04:20 +0800, "Y.J. Gu" 
> <guyingjie at huawei.com> wrote:
> > In RTSP 2.0, it is permitted to transmit several client requests in 
> > one Transport Connection.
> > I think this may introduce new problems when RTSP proxy is 
> intervened,
> and
> > existing RTSP can not deal with the scenario correctly.
> 
> I fail to see why.
> 
> > The following is an example. To display the figure 
> correctly, please 
> > maximize this email window.
> >    Suppose that client A and client B wants to join different 
> > multicast groups on the same server.
> (...) 
> > In this case, RTSP proxy can not distinguish the responses, then it 
> > may respond client with wrong message and induce client to join a 
> > wrong mutlicast group.
> 
> The RTSP proxy can (and in fact probably MUST) pair requests 
> and responses from the CSeq and/or from the ordering. As far 
> as I know, the RTSP server must send responses in the same 
> order as it receives requests (although it may interleave 
> some server-to-client requests).

If I understand correctly, you mean if RTSP proxy send Request A earlier
than Request B, then server must response A earlier than B. By this order,
RTSP proxy can pair the requests&responses. 
But what if server receive B earlier than A when traffic congest. Server
will response B earlier than A.

> Besides, I fail to see how this would be specific to multicast.

Yes, Multicast is an example, it is not specific to multicast. 

> --
> Rémi Denis-Courmont
>