[Serusers] another cancel test

Bogdan-Andrei IANCU iancu at fokus.fraunhofer.de
Tue Mar 1 20:36:01 CET 2005


Juha Heinanen wrote:

>Jan Janak writes:
>
> >   Actually I think that you should apply exactly the same logic as when
> >   processing the INVITE. CANCEL can be also sent end-to-end and in this
> >   case the user location lookup would be necessary to route it to the
> >   callee.
>
>jan,
>
>under what circumstances cancel is sent end-to-end?  my understanding
>from rfc3261 is that if a proxy has STATEFULLY forwarded an invite, the
>corresponding cancel is always a hop-by-hop request.  if invite was
>forwarded statelessly, then also cancel must be forwarded statelessly in
>the same way as invite, because there is no response context for it.
>
>so, if ser.cfg forwards all invites statefully, t_relay can be called on
>cancels without any request uri rewriting.
>  
>
SER does hop-by-hop CANCEL propagation. If the corresponding INVITE was 
forwarded statefully, TM will forward the CANCEL to exactly the same 
RURI as the INVITE disregarding completely the original CANCEL RURI - so 
in this case you have just to relay the CANCEL and TM will take care to 
send it to the right location.
if you have stateless INVITEs, you have to apply to CANCEL the same set 
of modifications as for INVITE.

bogdan




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