> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:sip-implementors- > [EMAIL PROTECTED] On Behalf Of Apoorva Bais > Sent: Monday, September 25, 2006 9:05 PM > To: Poojan Tanna > Cc: [email protected]; jafer sharif mohammed > Subject: Re: [Sip-implementors] query regarding CANCEL MESSAGE > > Just to add to all said before ! > > *INFO *may also be *cancelled* according to rfc-2976 > http://www.rfc-archive.org/getrfc.php?rfc=2976 > If a provisional response is received ! i am not quite sure what is the > use > and why one would do so ! > > [snip]
INFO can be used to carry MGCP events requesting detection/reporting of events (through RequestedEvents parameter and ObservedEvents parameter). CANCEL could be useful in this scenario. Here is a draft (expired) which discusses this: http://mirrors.isc.org/pub/www.watersprings.org/pub/id/draft-culpepper-sip-i nfo-event-00.txt This thread throws some light on your query: [Sipping] RFC 2976 INFO and CANCEL question http://www1.ietf.org/mail-archive/web/sipping/current/msg00048.html I think it's still an open question that CANCEL should not be used for methods other than INVITE. Does anyone know about any conclusion on this matter? RFC-3261 clearly states that "A CANCEL request SHOULD NOT be sent to cancel a request other than INVITE." [section 9.1 Client Behavior] Whereas RFC-2976 states otherwise: http://www.ietf.org/rfc/rfc2976.txt 2.4 Behavior of SIP User Agents An INFO request MAY be cancelled. A UAS receiving a CANCEL for an INFO request SHOULD respond to the INFO with a "487 Request Cancelled" response if a final response has not been sent to the INFO and then behave as if the request were never received. Regards, Bhaskar _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
