If the response is 408, then there is some kind of transport error at either UA. In that case, some kind of response to terminate Invite dialog (like 487) will also be probably not delivered to the UAC. So in this case, IMO, the UAS should silently terminate the dialog. 481 response could mean that probably UPDATE beat the 180 response, if UDP is used. Or it could be something similar to 408 case, where UAC does not know about the dialog, it created. But the UAS probably does not know reason for 481 response. In that case, UAS has the option of either terminating the dialog, without sending any final response or can send 487 to terminate the dialog.
Sanjay >-----Original Message----- >From: [EMAIL PROTECTED] >[mailto:[EMAIL PROTECTED] On Behalf Of >Nina Garaca >Sent: Tuesday, March 27, 2007 9:04 AM >To: [email protected] >Subject: [Sip-implementors] Strange situation with UPDATE request ??? > >Hi, > >I have some questions about the following situation: > >INVITE >|<--------------------------------------| >180 (with To tag) >|-------------------------------------->| /Early dialog established/ >UPDATE >|-------------------------------------->| >408/481 >|<--------------------------------------| >??? >|-------------------------------------->| > >/RFC 3261/15 says:/ >/ The caller's UA MAY send a BYE for either/ >/ confirmed or early dialogs, *and the callee's UA MAY send >a BYE on*/ >/* confirmed dialogs, but MUST NOT send a BYE on early dialogs.*/ >/* However, the callee's UA MUST NOT send a BYE on a >confirmed dialog*/ >/* until it has received an ACK for its 2xx response or >until the server*/ >/* transaction times out. */ > >/RFC 3311/5.3 //says:/ > /If a UA receives a non-2xx final response to a UPDATE, the session/ >/ parameters MUST remain unchanged, as if no UPDATE had been issued./ >/ Note that, as stated in Section 12.2.1 of RFC 3261 ><http://tools.ietf.org/html/rfc3261#section-12.2.1> [1 ><http://tools.ietf.org/html/rfc3311#ref-1>], *if the non-*/ >/* 2xx final response is a 481 (Call/Transaction Does Not >Exist), or a*/ >/* 408 (Request Timeout), or no response at all is received for the*/ >/* UPDATE (that is, a timeout is returned by the UPDATE client*/ >/* transaction), the UAC will terminate the dialog.*/ > >Q1: The question is, how can UA (that is callee/hasn't >initiated dialog) that has sent the UPDATE, terminate the >dialog, when that /*UA MUST NOT send a BYE*/? >Q2: What is the solution of this situation? > >Thanks in advance. >// > >* > >*-- >Nina Garaca >Software Development & Testing > >--- > >"ZESIUM mobile" d.o.o. >Valentina Vodnika 8/9 >21000 Novi Sad >Serbia >Tel: +381 (0)21 472 15 48 >Fax: +381 (0)21 472 15 49 >Mob: +381 (0)63 16 15 891 >E-mail: [EMAIL PROTECTED] > >_______________________________________________ >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
