[OpenSER-Users] Bug in 200 to CANCEL (wrong To_tag)

[Klaus Darilion]

Iñaki Baz Castillo schrieb:
> El Tuesday 23 October 2007 14:31:23 Klaus Darilion escribió:
>> And what says the RFC about a proxy which does parallel forking? Then
>> there may be multiple 180 ringing with multiple to tags. Which one
>> should be used?
> 
> Hi again.
> 
> Note that RFC 3261 assumes parallel forking in a different way as OpenSer 
> does. OpenSer just replies **one** final response to UAC but notes what RFC 
> 3261 says:

I think it does not assume a different way then Openser - this is just a 
race condition: proxy forwards to A and B. A sends 200. proxy sends 200 
to caller and CANCEL to B. If B picks up the phone and sends the 200 OK 
before the CANCEL arrives then the proxy should forward the 200 OK from 
B to the caller too and the caller has to deal to send a BYE to one of 
the calls.

Further this race condition is not related to you CANCEL problem as if 
there is already a 200 OK there will not be a CANCEL anymore, but a BYE.

regards
klaus


> 
> ------------------------------------------------------------------------
> 13.2.2.4 2xx Responses
> 
>    Multiple 2xx responses may arrive at the UAC for a single INVITE
>    request due to a forking proxy.  Each response is distinguished by
>    the tag parameter in the To header field, and each represents a
>    distinct dialog, with a distinct dialog identifier.
> ------------------------------------------------------------------------
> 
> 
> Of course, I can't understand how a UAC could handle various 200-OK when 
> establishing a dialog, RFC dreams I hope...
> 
> 
> 
> 
>