Jason Penton wrote:
Yes - I have. BUT I was under the impression that the 180 RINGING response is not REQUIRED to have a to-tag i.e. to set up an
early dialog.
Is this understanding correct?
indeed, to-tags serve the purpose if establishing a dialog. 180 does not establish any, only 183 does.
I disagree. The only difference between 180 and 183 is that 180 signifies that the callee is being alerted. Either may establish a dialog, or not.
So then to fix the problem I am having - I could
theoretically remove
the to-tags from all incoming 180 RINGING responses before
forwarding
them to the UAC and my problem should be solved.
You could also remove the call-id header too, but I wouldn't recommend it. The to-tag can validly be there. You can start playing games to work around bugs in devices you encounter, but that will be dangerous.
Paul
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Paul Kyzivat