On Mon, 2009-06-15 at 10:06 -0400, Beeton, Carolyn (CAR:9D60) wrote: > Part of the BLA I-D > (http://tools.ietf.org/html/draft-anil-sipping-bla-02) says (section 8): > "the State Agent MUST SUBSCRIBE > with a shorter expiration (expiration interval not smaller than 300 > seconds is RECOMMENDED) following the notification of a 'confirmed' > dialog or when a Event Agent honors a 'trying' for call origination, > with the user agents that notified it of this information." (the > purpose being to avoid tying up a shared line if one set dies while > holding it). > > To support this, I was planning to add an interface to the > SipSubscribeClient and the SipRefreshManager to change the subscribe > timeout. I am not sure how this would interact with what is proposed > here. I would want to see a failure response right away, so that the > shared line could be freed for other users.
The current proposal is that failure responses (either of the initial subscribe or of a re-subscribe) are reflected to the application promptly, which is the current behavior, so I don't think the XX-4591 fix will cause the SAA a problem. However, looking at changeXxxTimer, it looks like it only gives reasonable results if it is applied to an established subscription. I don't think that is a problem in practice. But there is some interaction between the user-requested refresh time and the retry/backoff algorithms, particularly the fact that the user-requested refresh time can change dynamically. Dale _______________________________________________ sipx-dev mailing list [email protected] List Archive: http://list.sipfoundry.org/archive/sipx-dev Unsubscribe: http://list.sipfoundry.org/mailman/listinfo/sipx-dev sipXecs IP PBX -- http://www.sipfoundry.org/
