A problem with 481 can be that the subscriber receiving 481 will consider the dialog as terminated,but the notifier will retain the dialog state.
Eventually the notifier will terminate the dialog on timeout and send a subscription terminated message to the subsciber. The subsciber on receiving this message will try to match a existing subscirption which it will nt find as the subscirption has already being terminated on its end and so it will send a 481 subscription does not exist. Thus this scenario will lead to a dis-graceful subscription termination with extra messaging overhead. One solution can be the notifier terminating the dialog at its end also before sending the 481 response,so that it need not send any more subscription terminated message,but still that will be a dis-graceful termination,other than that I think 405 is still a good option. Thanks and regards, Shamik Saha Project Engineer Voice Protocols Cell : +91-9886704155 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Attila Sipos Sent: Thursday, April 16, 2009 12:25 PM To: [email protected] Subject: [Sip-implementors] BYE after SUBSCRIBE? As we know, when a new SUBSCRIBE occurs, it creates a dialog. But what should one do when a BYE is received on a SUBSCRIBE dialog? I don't think "405 Method Not Allowed" is right but maybe "481"? I can't believe that BYE should clear the dialog because, IMO, BYE is only valid for INVITE-created dialogs. Regards, Attila _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors Please do not print this email unless it is absolutely necessary. The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately and destroy all copies of this message and any attachments. WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. www.wipro.com _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
