Re: [MMUSIC] WGLC for draft-ietf-mmusic-data-channel-sdpneg

Paul Kyzivat <pkyzivat@alum.mit.edu> Mon, 07 March 2016 00:32 UTC

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From: Paul Kyzivat <pkyzivat@alum.mit.edu>
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Date: Sun, 6 Mar 2016 19:32:33 -0500
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Subject: Re: [MMUSIC] WGLC for draft-ietf-mmusic-data-channel-sdpneg
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On 3/6/16 7:04 PM, Christian Groves wrote:
> Hello Flemming and Juergen,
>
> ..snip..
>>> I agree that in such cases such new attributes could indeed be added
>>> to corresponding data channel subprotocol specific attribute
>>> registries, which then could refer to the document introducing this
>>> new attribute.
>> Right - and for consistency I think it then makes sense to have all
>> subprotocol-specific attributes registered there.
>>
>>> An alternative might be to only add such a new SDP attribute to the
>>> generic IANA SDP attribute registry (which probably would be done
>>> anyhow). I assume that the generic SDP attribute registry would also
>>> refer to the document introducing this new attribute.
>>>
>> Either would work, however my preference would be a complete listing
>> of attributes that have subprotocol specific meaning.
>>
>> I'd be interested in what other people think though
>
>  From looking at the existing IANA registry
> http://www.iana.org/assignments/sdp-parameters/sdp-parameters.xhtml
>
> It feels like we should take the approach for att-field (source level)
> and define att-field (data channel).

I have previously proposed (and I think it was approved) that the use of 
separate sub-registries for session-only, media-only, session-and-media, 
and source level is a pain, and error prone, and should be replaced by a 
single registry with another column where session, media, and/or source 
level can be specified.

And, this particular discussion started when I proposed that yet another 
option for that new field ought to be data-channel.

Flemming disagreed - IIUC he felt it was unnecessary. I still think it 
is at least as necessary as is having a registry for source level.

An argument can be made that *none* of these need to be specified in the 
registry (that it is sufficient for them to be defined in the document), 
but if this info *is* to be in a registry then it makes just as much 
sense to include it for data-channels as for the others.

	Thanks,
	Paul.