Is there a scenario, where even BYE from UA on the dialog does not result in deletion of the dialog?

Is there a scenario, where even BYE from UA on the dialog does 开发者_StackOverflow社区not result in deletion of the dialog? If so, can you please give an example for such scenario...

If you use RFC3265 the reception of a BYE for a call having pending subscriptions will not terminate the dialog. See RFC 3265 Section 3.3.4. Dialog creation and termination

If a UA doesn't receive the BYE, then of course it cannot know that the remote party has gone.

In that case, there are a few ways for it to realise that the dialog has in fact been terminated: it can use session timers, or watch what happens on the media plane - did those TCP connections terminate? have the RTCP reports stopped arriving? - or other mechanisms.

But otherwise, for the UA sending the BYE, the dialog has immediately terminated.