Hi All, According to the 3GPP 24.229 spec,
Upon successful de-registration UA should not delete the dialog for Subscription to reg event package if it had subscribed. Exerts from 24.229: ------------------------------------------------------------------------------------------------------------------------------------ Prior to sending a REGISTER request for deregistration, the UE shall release all dialogs related to the public user identity that is going to be deregistered or to one of the implicitly registered public user identities. However: - if the dialog that was established by the UE subscribing to the reg event package used the public user identity that is going to be deregistered ; and - this dialog is the only remaining dialog used for subscription to reg event package;then the UE shall not release this dialog. ----------------------------------------------------------------------------------------------------------------------------------------- What is the use of keeping this dialog when registration itself is removed as Subscription to reg event package tells about the registration status.Upon successful de-registration UA knows that its registration status for that user is terminated.So is it not right to delete the Subscription to reg event package on deregistration ? Also from the same spec,it tells that if signaling security is involved(IPsec/tls),on deregistration security associations will be deleted and further messages can not be received. So if UA does keep the dialog even after deregistration and the server tries to send NOTIFY WITH TERMINATED STATE ,it won't reach the UA as already security associations are deleted. ------------------------------------------------------------------------------------------------------------- When the UE has received the 200 (OK) response for the REGISTER request of the only public user identity currently registered with its associated set of implicitly registered public user identities (i.e. no other is registered), the UE removes the security association established between the P-CSCF and the UE. Therefore further SIP signalling (e.g. the NOTIFY request containing the deregistration event) will not reach the UE. --------------------------------------------------------------------------------------------------------------------------------------- So it makes sense to delete the Subscription to reg event package on deregistration without waiting for NOTIFY WITH TERMINATED STATE . Please opine. Regards, Sunil _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
