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

[Alex Balashov]

Iñaki Baz Castillo wrote:
> 2009/5/22 Alex Balashov <abalashov at evaristesys.com>:
> 
>> Simply looking up in a table whether a transaction with that GUID and tags
>> is currently being tracked is not logically equivalent to fully
>> importing/superimposing all INVITE transaction state into the processing
>> context for CANCEL
> 
> Note that Kamailio does more than it when processing a CANCEL. When
> doing "t_relay()" for a CANCEL the destination is retrieved from the
> matching INVITE transaction, this is, you don't route the CANCEL,
> instead "tm" module routes it to the same location the INVITE was
> routed.

Hmm, that's true.  End-to-end CANCELs aren't sent by the originating UA 
to the destination URI of the far end, are they?  Otherwise they would 
be routed like any other sequential in-dialog request, and they're not.

I'm curious, why are they designed that way?  Why not route end-to-end 
CANCELs the same way one routes end-to-end BYEs?

-- 
Alex Balashov
Evariste Systems
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