Hagai Sela (TA) wrote:
> Hi,
> How many concurrent UAC transactions may a dialog have? let's say I just
> sent OPTIONS in an established dialog, and no response was received yet.
> At this point I want to send BYE. Do I have to wait for the OPTIONS
> response to send the BYE request?
You have asked two questions. The last one is easier to answer: no you
don't have to wait - you can send the BYE immediately if you wish.
The first question has no fixed answer. In theory there could be any
number of transactions in progress, but in practice that is unlikely.
Any time there are multiple transaction active concurrently there is a
possibility that they will arrive out of order. When that happens, the
one that arrives first is processed successfully, and the ones that were
bypassed will all fail because their CSeq value is too low. The
possibility of this sort of failure limits the cases where it makes any
sense to send concurrent transactions. The second case you mention is
one where it does make sense.
A case that could result in an arbitrary number of transactions going:
S is a subscriber that has subscribed to notifier N. N sends a
notification. For some reason the response to that is not received by N.
(S could be bottlenecked, or there could be problems in the return
network path.) The state of the notifier continues to change and so it
continues to send more notify messages, none of which get responses.
Paul
_______________________________________________
Sip-implementors mailing list
[email protected]
https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
