[Kamailio-Devel] Flags are not visible when processing CANCEL

[Iñaki Baz Castillo]

2009/5/22 Alex Balashov <abalashov at evaristesys.com>:
> Iñaki Baz Castillo wrote:
>
>> Hi, using Kamailio 1.5 I've realized that INVITE transaction flags are
>> not visible during CANCEL processing, this is:
>
> Well, a CANCEL is a different initial request and therefore a different
> transaction, no?   It has the *effect* of canceling an existing transaction,
> but is not in itself part of that transaction, I would have thought, at
> least in the way that governs the awareness of the transactional layer in
> stateful proxies per the RFC.
>
> I could be wrong...

Yes, you are right. However, Kamailio "extends" the transaction
concept (since it's useful).

For example, "t_check_trans()":
- CANCEL request - true if the cancelled INVITE transaction exists.
- ACK request - true if the ACK is a local end-to-end ACK
corresponding to an previous INVITE transaction.

This is, even if ACK (end-to-end for a 200 OK) and CANCEL are an
"indepent" transaction, Kamailio knows that them belongs to an INVITE
transaction.

Based on it, I think that Kamailio could retrieve INVITE transaction
flags when CANCEL or ACK (end-to-end) arrives.

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