Re: [MMUSIC] ice-options attribute: session- and media-level?

[Christer Holmberg <[e-mail]>]

Hi,

>>>> The draft defines the ice-options SDP attribute, so the draft needs 
>>>> to define what type (media and/or session) of SDP attribute it is.
>>>
>>> At the syntax level, yes. Sematically, however, is it perhaps the job 
>>> of the ICE specification to define whether ICE extensions (however 
>>> encoded in a using protocol) are session-level or media-level?
>> 
>> whether session level, media level, or both is required as part of the 
>> registration of the attribute. It is considered part of the syntax 
>> even though it isn't part of the ABNF.
>> 
>> Of course the semantics of its use is also tied up in whether it is 
>> session or media level, and so needs to be described as part of the 
>> semantics as well.
>
> Hi Paul,
>
> I guess my concern is this: now that we've decoupled ICE from SDP, we might lose synchronization between SDP bindings 
> and non-SDP bindings, which wouldn't be good for interoperability. As I understand it, the ice-options attribute can include 
> a variety of tokens (e.g., 'ice2' or 'rtp+ecn'). Should it be the responsibility of a token spec to specify whether a token is session 
> level or media level, or is that best handled at the attribute layer? I am not an SDP expert so I might be missing something fundamental...

Assuming that ICE options can be both media and session, I think each individual token spec needs to define which it is applicable to. However, RFC 6336 does not currently require to explicitly indicate whether an option is media and/or session - eventhough a description of the token is required.

But, never the less, the ice-sip-sdp draft still needs to define whether the ice-options SDP attribute is media, session or both :)

Regards,

Christer