The following errata report has been submitted for RFC4028, "Session Timers in the Session Initiation Protocol (SIP)".
-------------------------------------- You may review the report below and at: http://www.rfc-editor.org/errata_search.php?rfc=4028&eid=1687 -------------------------------------- Type: Technical Reported by: Radha krishna Saragadam <[email protected]> Section: 9 Original Text ------------- The UAS MUST NOT increase the value of the Session-Expires header field. Corrected Text -------------- same as session 8.1 If the request doesn't indicate support for the session timer but contains a session interval that is too small, the UAS cannot usefully reject the request, as this would result in a call failure. Rather, the UAS SHOULD insert a Min-SE header field containing its minimum interval. If a Min-SE header field is already present, the UAS SHOULD increase (but MUST NOT decrease) the value to its minimum interval. The UAS MUST then increase the Session-Expires header field value to be equal to the value in the Min-SE header field Notes ----- ----- Forwarded Message ---- From: Radha krishna <[email protected]> To: Brett Tate <[email protected]>; "[email protected]" <[email protected]> Sent: Thursday, February 19, 2009 10:56:31 AM Subject: Re: [Sip-implementors] Sending 422 Thanks Brett, So I think same should be added for UAS <Snip from RFC section 8.1> If the request doesn't indicate support for the session timer but contains a session interval that is too small, the proxy cannot usefully reject the request, as this would result in a call failure. Rather, the proxy SHOULD insert a Min-SE header field containing its minimum interval. If a Min-SE header field is already present, the proxy SHOULD increase (but MUST NOT decrease) the value to its minimum interval. The proxy MUST then increase the Session-Expires header field value to be equal to the value in the Min-SE header field, as described above. </Snip from RFC> Regards S.Radha krishna ________________________________ From: Brett Tate <[email protected]> To: Radha krishna <[email protected]>; "[email protected]" <[email protected]> Sent: Wednesday, February 18, 2009 6:42:31 PM Subject: RE: [Sip-implementors] Sending 422 It looks like Section 9 may have forgotten to indicate the behavior when UAC timer support not indicated. Section 8.1 allows a proxy to increase the Session-Expires; I see no reason why the same cannot be done by the UAS. > -----Original Message----- > From: [email protected] [mailto:sip- > [email protected]] On Behalf Of Radha krishna > Sent: Tuesday, February 17, 2009 9:48 PM > To: [email protected] > Subject: [Sip-implementors] Sending 422 > > Hi > > Consider the following topology > UA1 ----- Call-stateful-proxy ------ UA2 > > UA1 does not support session timer, Make a call to UA2. Call- > stateful-proxy adds Session-Expires:100 header and forwards to UA2. UA2 > minimum session expires is 900. But in this case INVITE will not contain > "support: timer". According section 9, UAS can reject with 422 only if > there is a timer tag in supported header > > <Snip from RFC> > > If an incoming request contains a Supported header field with a value > 'timer' and a Session Expires header field, the UAS MAY reject the > INVITE request with a 422 (Session Interval Too Small) response if > the session interval in the Session-Expires header field is smaller > than the minimum interval defined by the UAS' local policy. When > sending the 422 response, the UAS MUST include a Min-SE header field > with the value of its minimum interval. This minimum interval MUST > NOT be lower than 90 seconds. > </Snip from RFC> > > Also UAS cannot increase the session expires duration > <Snip from RFC> > The UAS MUST > NOT increase the value of the Session-Expires header field. > </Snip from RFC> > > What should be the behavior of UAS here? > 1) accept the call with 100 seconds? > 2) Increase the duration to 900 seconds while sending 200 Ok? > Note: Session timer should not be turned-off > > Regards > S.Radha krishna > > > > > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors Instructions: ------------- This errata is currently posted as "Reported". If necessary, please use "Reply All" to discuss whether it should be verified or rejected. When a decision is reached, the verifying party (IESG) can log in to change the status and edit the report, if necessary. -------------------------------------- RFC4028 (draft-ietf-sip-session-timer-15) -------------------------------------- Title : Session Timers in the Session Initiation Protocol (SIP) Publication Date : April 2005 Author(s) : S. Donovan, J. Rosenberg Category : PROPOSED STANDARD Source : Session Initiation Protocol Area : Real-time Applications and Infrastructure Stream : IETF Verifying Party : IESG _______________________________________________ Sip mailing list https://www.ietf.org/mailman/listinfo/sip This list is for NEW development of the core SIP Protocol Use [email protected] for questions on current sip Use [email protected] for new developments on the application of sip
