From: "Ajit Kumar" <[EMAIL PROTECTED]> Suppose I am already having an established SUBSCRIBE dialog and the subscription expires after 700sec. Now, I am doing a Re-Subscribe to refresh my Subscription with a lesser value say 300sec. The Notifier sends 200ok for the re-subscribe with Expires 250 say. Now I have set my expiry to be 250sec. After getting the 200Ok for Re-Subscribe I got a Notify which suggests Expires to be 400sec, this notify can be the delayed Notify of my previous subscription which was supposed to expire after 700sec. Now, how I should respond to this Notify, as my current expires is 250 and what I am getting is exceeding the value I proposed in Re-Subscribe.
It's a messy problem. There was a discussion on the SIP mailing list a month or so ago, but I'm so far behind on my e-mail, I don't know if a consensus was reached. At one point, I advocated that once a subscription endpoint was established, both the Subscriber and the Notifier would be constrained to only push the endpoint further into the future (except when terminating the subscription immediately). That eliminates many ambiguities. In the specific case you describe: Clearly, you should respond 200 to the NOTIFY. Because the NOTIFY was likely sent by the Notifier before the re-subscribe, the Subscriber should retain the earlier subscription endpoint (250 secs.), which was agreed upon after the later subscription endpoint. This policy is safe... Dale _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
