As Paul mentioned, the 500 doesn't terminate the dialog. The notifier needs to decide what should occur: do nothing, resend with higher cseq (same content or full content), or send terminating NOTIFY incase non recoverable cseq issue. Unfortunately the 500 doesn't only mean cseq out of order.
Depending upon notifiers ability and need to successfully recover from the 500 response situation, the notifier may choose to send a terminating NOTIFY. The subscriber may choose to subsequently create another subscription. > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On > Behalf Of Pascal Maugeri > Sent: Wednesday, September 17, 2008 9:42 AM > To: [email protected] > Subject: [Sip-implementors] Subscription state at both UAC > and UAS when UACsends "500 Request out of order" > > Hi > > I have the following scenario where a UAC subscribe to a UAS > a SIP SUBSCRIBE request, receive SIP NOTIFY messages > (RFC3265) and then the UAC receives from the UAS a SIP NOTIFY > with a CSeq number out of order (eg. it receives a NOTIFY > with CSeq=10 and then a NOTIFY with CSeq=9). In this case the > UAC replies to UAS with an error response 500 Request Out Of order. > > At this point how the UAC should consider the subscription state ? > terminated or active ? > Same question for the UAS ? > > Regards, > Pascal > _______________________________________________ > 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
