> From: Brez Borland [[email protected]] > > Alice places a call(INVITE) to Bob, where Bob has multiple devices > registered to his URI. INVITE is forked, and all the Bob's devices ring. Bob > answers the call on one device. > > What I am thinking is, would you imagine Alice placing another call to the > same URI of Bob's, while the first call is still in progress? > Would Bob's phone ring while he is still chatting on the first call with > Alice? > > Should Alice's phone client disallow this? Or am I missing something in the > SIP(and calling related) protocol that accounts for this?
SIP allows and supports this. I could probably design a situation where this behavior (on Alice's part) would be natural, but it would take more time than I am willing to devote. More importantly, be aware: 1. Alice's UA cannot reliably determine that the second call is intended to be to the same destination as the first call. All that it can determine is whether or not Alice entered the same dial string. But due to the forking of the call to multiple UASs and possibly time-varying routing of the AOR, it is impossible for the UAC to determine that the second call will go to the same destination as the first one. 2. Bob's UA cannot reliably determine that the second call is from the same UAC as the first call. Even the Contact URIs in the INVITEs may be different (especially if the calls go through a B2BUA). So Alice's UA may forbid a second call, but only if it *always* forbids handling a second call. Similarly Bob's UA may forbid a second call, but only if it *always* forbids handling a second call. Dale _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
