Hi, Paul: I am glad to see your note because all readers will know exactly how it works.
BTW, I am curious to know: Why is there no such interest to have the features to know capabilities before the call setup? If we could do so, could we could not save some roundtrip delays during negotiations? Will it not reduce the post-dial call setup time? Best regards, Radhika R. Roy [EMAIL PROTECTED] -----Original Message----- From: Paul Long [mailto:[EMAIL PROTECTED]] Sent: Wednesday, February 12, 2003 10:49 AM To: Sip-Implementors (E-mail) Subject: RE: [Sip-implementors] SIP2H323 IWF Roy, Indeed, there is no _exact_ equivalent in H.323, although "features" can be signaled prior to call establishment (Connect) via FeatureDescriptors. If either endpoint decides that the other endpoint doesn't support what it needs, it can terminate call-setup before the call is established by sending ReleaseComplete. Also, H.450.12 allows an endpoint to determine, typically during call-setup, which supplementary services another endpoint supports. Both mechanisms are optional and must be used within the context of a call, however. The ability to convey this information outside the context of a call has been considered, but there hasn't been much, if any, interest in such a feature. If only for SIP-H.323 interworking, however, maybe it's time to add it to H.323. It should be pretty easy. Paul -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Roy, Radhika R, ALABS Sent: Tuesday, February 11, 2003 10:12 AM To: Jade Chen Yan; Sip-Implementors (E-mail) Subject: RE: [Sip-implementors] SIP2H323 IWF Hi, Jade: OPTION is a powerful feature of SIP and there is no equivalent in H.323. In H.323, one needs to set up calls to find out capabilities. The draft IWF specification is yet to address this. Best regards, Radhika R. Roy [EMAIL PROTECTED] -----Original Message----- From: Jade Chen Yan [mailto:[EMAIL PROTECTED]] Sent: Tuesday, February 11, 2003 4:25 AM To: Sip-Implementors (E-mail) Subject: [Sip-implementors] SIP2H323 IWF hi, list we know the H323's capability exchange requires an establishing call.. when a sip UA sends OPTION to a H323 terminal via a IWF,. what shall we do?how can we querry H323 capabilites without esatablishing a call? B.Regards, Jade _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
