2009/3/17 <javier.ferreirogar...@telefonica.es>: > The current approach, when changing operational mode on the fly, is to > unsubscribe prior to automatic deregistration, then perform initial > registration of the new "feature tag" and perform initial subscription to > all event-packages. The overhead in terms of SIP messages is significant, > so we are wondering if it is possible to reuse "old" subscriptions. When > unregistering old contact and registering the new; the IP address in the > Contact keeps the same, the only item that changes is the feature tag. > Is this allowed according to RFC 3261?
A subscription is independent from the registration. When you send the SUBSCRIBE a dialog is created where your URI is the Contact you used in the initial SUBSCRIBE. You can un-REGISTER later or change your Registration Contact URI, it doesn't matter, you will still receive NOTIFY's of the subscription to the initial Contact. So, when you want to un-register and re-register with a different Contact URI, you don't need to end your subscriptions (by sending a SUBSCRIBE with "Expires: 0"). About the registrations itself, take into account that two URI's with same user, host, port are different if they contain the same parameter with different value. In your case it doesn't occur since both are different parameter names. I don't see problems with your approach. Hope it helps. -- Iñaki Baz Castillo <i...@aliax.net> _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
