[Serusers] another cancel test

[Juha Heinanen]

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.

-- juha