Hi, Thanks for your response. In this case UAS has received UPDATE request before receiving the ACK for the INVITE.
In my case UAS is not sending any response for that UPDATE. So my question is that What will be the response for this UPDATE? I have found one testcase in the link https://www.cisco.com/en/US/docs/ios-xml/ios/voice/sip/configuration/15-mt/voi-sip-rfc.html#GUID-0C33CD1F-D738-481D-BC59-34A782986D4A I have not found any supported link in any RFC the behavior mentioned in that link. Error Responses to UPDATE Request Processing Before the Call Is Active In other scenarios, additional rules apply to processing an UPDATE request with an offer when the gateway has sent a 200 OK response to an INVITE request but has not yet received an ACK. The following scenarios generate an error response and are shown in the figure below: * If the initial INVITE request contains an offer but does not require provisional responses be sent reliably, then the SDP in the 200 OK is treated like an answer. If the UAS then receives an UPDATE request before an ACK response to the 200 OK, the UAS sends a 500 Server Internal error response with a Retry-After header. * If the initial INVITE does not contain an offer and does not require provisional responses be sent reliably, then the SDP in the 200 OK is treated like an offer. If the UAS then receives an UPDATE request before receiving an ACK to the 200 OK, the UAS sends a 491 Request Pending response. Figure 5. Error Cases for UPDATE Requests Due to that UAC is retransmitting UPDATE continuously and finally it is terminating the dialog on not receiving any final response that UPDATE. This is as per RFC 3311. On Tuesday, 29 October 2013 7:53 PM, Paul Kyzivat <pkyzi...@alum.mit.edu> wrote: On 10/29/13 9:55 AM, Sourav Dhar Chaudhuri wrote: > Hi, > I need the expected response for the Call scenario mentioned below > > 1) UAC sends INVITE request with SDP > > 2) UAS sends 180 ringing to UAC > > 3) Then UAS sends 200 OK fo with SDP response INVITE . > > 4) Now after receiving 200 OK response by UAC. it generates UPDATE request > with same SDP mentioned in STEP 1 towards UAS. Is it a valid behavior? > > 5) Now what should be the response from UAS for that UPDATE request ?? > > After sending the UPDATE request UAC has also also ACK request for 200 OK >response. The UAS is receiving the UPDATE before the ACK? The UPDATE seems silly, but not *wrong*. The UAS receiving the UPDATE before the ACK isn't proof that they were sent in that order. And even if they were it isn't really wrong as long as the ACK is sent in a timely way. As far as what the UAS should respond, this is a new offer. All the same rules apply as if it were sent long after the INVITE transaction completed. Thanks, Paul _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
