[vlc-devel] Rép . : Re: commit: Qt4: fix default port numbers in streaming wizard ( Rémi Denis -Courmont )

[Rémi Denis-Courmont]

Le jeudi 26 novembre 2009 20:50:33 Marian Ďurkovič, vous avez écrit :
>    However, port numbers 5004 and 5005 have been registered for use with
>    this profile for those applications that *choose* to use them as the
>    default pair.
> 
> Thus, default port is application matter.

It means apps with a static default should use 5004-5005, in contrast to apps 
that use a dynamic pair (such as RTSP clients).

> It's nothing like port 80 for HTTP.

Sure, it's nothing like port 80 because applications are expected to signal 
the port number via an out-of-band mechanism, such as a SDP description. So 
the default is supposed to be largely irrelevant. That's why there is no URI 
scheme for RTP either.

> VLC is using 1234 for many years and everyone knows that. Such use
>  is perfectly valid and multiple firewalled networks are configured to
>  handle it correctly. Those who can't configure their firewall should
>  learn.

VLC has been using 5004 on input by default since 0.9.0, for almost a year and 
a half.

> That's more a disadvantage. Requires two ports to be opened on the
>  firewall. And BTW, autoselecting between TS over raw UDP and TS over
>  RTP/UDP is trivial, older VLC versions were doing it fine.

Detecting whether a packet is TS or RTP is easy. But VLC plugins cannot decide 
dynamically whether to use access or access_demux at the moment, thus it's 
impossible.

> >  - 5004 is not allocated to something else.
> 
> Which RFC registers 1234 as the standard port for something else?

TCP/1234 and UDP/1234 are registered to the Infoseek Search Agent. An RFC was 
never needed to allocate a port number with IANA.

-- 
Rémi Denis-Courmont
http://www.remlab.net/