Hi Shida, I think the semantics in your question are about SIP protocol level negotiation vs. event package level negotiation. The SA draft is extending RFC 4235 for the shared appearences feature. I see it as more of an event package extension as opposed to a SIP option tag extension.
Just my 2 cents, Raj On Thu, Nov 19, 2009 at 7:09 PM, Shida Schubert <[email protected]> wrote: > > I think option tag is necessary if UA that does not understand > this specification barfs or breaks by receiving the parameter > mentioned. > > Regards > Shida as an individual. > > On Nov 9, 2009, at 4:38 PM, Alan Johnston wrote: > >> Here's an issue Robert has raised that we should have some discussion on >> before sending this on the IESG. >> >> The Shared Appearance draft defines a "shared" event parameter. >> >> The question is whether this should instead be a SIP feature tag used in a >> Supported and Require header fields. >> >> I've pulled out some text from the draft, RFC 3265, and a summary of how it >> is used. >> >> What do people think? >> >> Thanks, >> Alan >> >> - - - - - >> >> From draft-bliss-shared-appearance: >> >> Section 12.1 >> >> This specification defines a new event parameter 'shared' for the >> Dialog Package. When used in a NOTIFY, it indicates that the >> notifier supports the shared appearance feature. When used in a >> PUBLISH, it indicates that the publisher has explicit appearance >> information contained in the message body. If not present in a >> PUBLISH, the Appearance Agent MAY assign an appearance number to any >> new dialogs in the message body. >> >> From RFC 3265: >> >> 4.4.2. Event Package Parameters >> >> If parameters are to be used on the "Event" header to modify the >> behavior of the event package, the syntax and semantics of such >> headers MUST be clearly defined. >> >> Details on the usage: >> >> - Appearance Agent discovery of non-Shared Appearance UA during >> subscriptions. A NOTIFY sent without <appearance> elements does not >> necessarily mean the UA does not understand or support the extension, but a >> NOTIFY sent without the Event:dialog;shared does indicate this. >> >> - Sent by a UA and interpreted by an Appearance Agent to request no >> appearance number be assigned to a dialog (PUBLISH sent without <appearance> >> attribute but containing Event: dialog;shared >> >> >> _______________________________________________ >> BLISS mailing list >> [email protected] >> https://www.ietf.org/mailman/listinfo/bliss > > _______________________________________________ > BLISS mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/bliss > _______________________________________________ BLISS mailing list [email protected] https://www.ietf.org/mailman/listinfo/bliss
