RE: Session timer question
Drage, Keith (Keith <drage <at> lucent.com>
2003-12-01 18:41:05 GMT
I think this is answered by subclause 8.2.4 of RFC 3261, viz:
8.2.4 Applying Extensions
A UAS that wishes to apply some extension when generating the
response MUST NOT do so unless support for that extension is
indicated in the Supported header field in the request. If the
desired extension is not supported, the server SHOULD rely only on
baseline SIP and any other extensions supported by the client. In
rare circumstances, where the server cannot process the request
without the extension, the server MAY send a 421 (Extension Required)
response. This response indicates that the proper response cannot be
generated without support of a specific extension. The needed
extension(s) MUST be included in a Require header field in the
response. This behavior is NOT RECOMMENDED, as it will generally
break interoperability.
Any extensions applied to a non-421 response MUST be listed in a
Require header field included in the response. Of course, the server
MUST NOT apply extensions not listed in the Supported header field in
the request. As a result of this, the Require header field in a
response will only ever contain option tags defined in standards-
track RFCs.
regards
Keith
> -----Original Message-----
> From: Veda Hegde [mailto:vhegde <at> san.rr.com]
> Sent: 01 December 2003 18:27
> To: Paul Kyzivat; Rosen Brian
> Cc: sip <at> ietf.org
> Subject: Re: [Sip] Session timer question
>
>
> Hi:
> I don't think it says in the draft that a proxy/UAS can not
> put Require:
> timer in 2xx, if UAC did not include Supported: timer in the request.
> May be this should be specified in the draft.
> Veda
>
>
> ----- Original Message -----
> From: "Paul Kyzivat" <pkyzivat <at> cisco.com>
> To: "Rosen, Brian" <Brian.Rosen <at> marconi.com>
> Cc: <vhegde <at> san.rr.com>; <sip <at> ietf.org>
> Sent: Monday, December 01, 2003 7:36 AM
> Subject: Re: [Sip] Session timer question
>
>
> > Brian,
> >
> > The question was about a Require in a 200 response to an
> invite. The UAC
> > clearly can't return a 420 in that case.
> >
> > I don't think any valid usage of session timer will ever
> result in this
> > case. The only cases where Require: timer is validly put into the
> > response are when the request contained Supported: timer.
> >
> > So this can only result from a broken proxy or UAS. In this
> case I think
> > the UAC is justified in either sending an ACK and then BYE as you
> > suggest, or else just ignoring the Required: timer.
> >
> > Paul
> >
> > Rosen, Brian wrote:
> > > You send 420 - Bad Extension, because you don't understand the
> > > timer option in the Require. See section 8.2.2.3 in RFC3261.
> > >
> > > Brian
> > > -----Original Message-----
> > > From: vhegde <at> san.rr.com [mailto:vhegde <at> san.rr.com]
> > > Sent: Friday, November 28, 2003 9:13 PM
> > > To: sip <at> ietf.org
> > > Subject: [Sip] Session timer question
> > >
> > >
> > > Hi:
> > > I have a question on session timer message flow.
> > >
> > > If a UA does not support session timer and if it receives
> > >
> > > Require: timer
> > > Session Expires: 3600
> > >
> > > in the 200 OK to re-INVITE what is the correct way to process this
> response?
> > >
> > >
> > > Should UAC Ack the 200 OK and then send a bye or ignore
> the Require and
> > > session Expires: headers and continue with rest of the processing?
> > >
> > > Veda
> > >
> > > _______________________________________________
> > > Sip mailing list https://www1.ietf.org/mailman/listinfo/sip
> > > This list is for NEW development of the core SIP Protocol
> > > Use sip-implementors <at> cs.columbia.edu for questions on current sip
> > > Use sipping <at> ietf.org for new developments on the
> application of sip
> > >
> >
> >
> > _______________________________________________
> > Sip mailing list https://www1.ietf.org/mailman/listinfo/sip
> > This list is for NEW development of the core SIP Protocol
> > Use sip-implementors <at> cs.columbia.edu for questions on current sip
> > Use sipping <at> ietf.org for new developments on the application of sip
> >
>
>
>
> _______________________________________________
> Sip mailing list https://www1.ietf.org/mailman/listinfo/sip
> This list is for NEW development of the core SIP Protocol
> Use sip-implementors <at> cs.columbia.edu for questions on current sip
> Use sipping <at> ietf.org for new developments on the application of sip
>
_______________________________________________
Sip mailing list https://www1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use sip-implementors <at> cs.columbia.edu for questions on current sip
Use sipping <at> ietf.org for new developments on the application of sip
>
> My question is if there is any draft of plan to implement ENUM-lookups
> into the SIP-protocol?
>
> Rene Bartsch
>
>
> _______________________________________________
> Sip mailing list 
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