On Friday 30 April 2010, Iñaki Baz Castillo wrote:
[..] Not exactly, sorry, the proxy should forward the CANCEL stateless:
16.10 CANCEL Processing [...] If a response context is not found, the element does not have any knowledge of the request to apply the CANCEL to. It MUST statelessly forward the CANCEL request (it may have statelessly forwarded the associated request previously).
Hi Iñaki,
ok, but i think in the default server configuration we don't do it this way:
if (is_method("CANCEL")) { if (t_check_trans()) t_relay(); exit; }
We just drop them. In the sr configuration i think there is also a similar method implemented (etc/sip-router.cfg, route[CATCH_CANCEL]). In the past on our systems we've tried to forward them stateless, but this created some loop conditions, if i remember correctly. Sending a final response to the CANCEL (e.g. 491) also not worked out really well.
Henning