Re: [MMUSIC] RTSP: Proxies and handling of unknown methods, headers and transport parameters

[Magnus Westerlund <magnus.westerlund at ericsson.com>]

HAAS Christian skrev:
> Hello;
> 
> The additions are ok from my view, only one issue:
> 
> From: Magnus Westerlund [mailto:magnus.westerlund at ericsson.com] 
>> 16.51.  Transport
>> [...]
>> If not transport specification is supported an empty header
>> is returned and the request SHALL be responded using the
>> status code 461 (Unsupported Transport) (Section 15.4.13). 
>> [...]
> 
> Apart from that the transport header does not allow to be empty (ABNF), I see
> no reason to return it at all, since the response code already tells what the
> problem is.
> (The same paragraph is repeated for proxies).

Okay, you are correct, it is not needed.

> 
> But we could consider that the server does return a transport header in the
> 461 response, filled with a list of transport-spec that he supports (for
> given resource). Since it's a general 'supporting' response, the
> transport-spec might only consist of transport-id (like "RTP/UDP") and
> possibly one of "multicast" or "unicast" parameter for further limitation.
> Proxies in the chain would then as well remove any entries they don't support
> (finally removing the header all together when the last entry was removed),
> leaving the client with a list of possible transports which then could ask
> the user to re-enable a transport that was not tried before.
> But I don't know if this would be a wanted feature mainly for usability...
> 

My personal view is that there is a big difference between capability
declaration which you want in the 461 response and the configuration and
configuration negotiation that Transport header carries normally. I
think there is a point to use another structure and thus a new header
for that.

I will log a feature request for this, for future consideration.

Cheers

Magnus Westerlund

IETF Transport Area Director & TSVWG Chair
----------------------------------------------------------------------
Multimedia Technologies, Ericsson Research EAB/TVM
----------------------------------------------------------------------
Ericsson AB                | Phone +46 8 4048287
Färögatan 6                | Fax   +46 8 7575550
S-164 80 Stockholm, Sweden | mailto: magnus.westerlund at ericsson.com
----------------------------------------------------------------------
_______________________________________________
mmusic mailing list
mmusic at ietf.org
https://www.ietf.org/mailman/listinfo/mmusic