[Kamailio-Devel] Does Kamailio respect custom headers in CANCEL?

[Iñaki Baz Castillo]

2009/2/9 Iñaki Baz Castillo <ibc at aliax.net>:
> Hi, since CANCEL is hop by hop, a proxy doesn't require to respect
> custom headers in a CANCEL request. But it would be very useful in
> order to implement some especifications (as "Reason" header defined in
> RFC 3326).
>
> So, in case Kamailio receives a CANCEL with a header:
>
>  Reason: SIP ;cause=200 ;text="Call completed elsewhere"
>
> Would Kamailio include this header in the CANCEL it generates for the
> pending branches?
> If not, is it feasible with the current design?

RFC 3326 makes mandatory that a proxy should respect a Reason header
when receiving a CANCEL and include it into its generated CANCEL's:

Section 2 of RFC 3326 says

  Proxies generating a CANCEL request upon reception of a CANCEL from
  the previous hop that contains a Reason header field SHOULD copy it
  into the new CANCEL request.

  In normal SIP operation, a SIP status code in a response provides the
  client with information about the request that triggered the
  response, the session parameters, or the user.  For example, a 405
  (Method not allowed) response indicates that the request contained an
  unsupported method.  A 488 (Not Acceptable Here) indicates that the
  session parameters are unacceptable and a 486 (Busy Here) provides
  information about the status of the user.

So this means that Proxies SHOULD forward the CANCEL request that
contains Reason header.



-- 
Iñaki Baz Castillo
<ibc at aliax.net>