[SR-Users] Late parallel forking

[Daniel-Constantin Mierla]

On 24/07/14 09:43, Olle E. Johansson wrote:
> On 24 Jul 2014, at 09:38, Klaus Darilion <klaus.mailinglists at pernau.at> wrote:
>
>>
>> On 21.07.2014 14:59, Daniel-Constantin Mierla wrote:
>>> Hello,
>>>
>>> you may get similar results using t_cancel_callid(():
>>> - http://kamailio.org/docs/modules/stable/modules/tmx.html#idm8272
>>>
>>> For each call you have to store the call-id, cseq and the target user
>>> somehow (e.g., using htable).
>>>
>>> Then, when you have a registration, see if the user has an ongoing call
>>> towards him/her. If yes, cancel that transaction and you end up in
>>> failure route. Based the flags, you can see it was canceled on purpose
>>> and can do another lookup location to get now two branches.
>>>
>>> You would need to store the initial caller address before looking up
>>> location, revert to it in failure route before looking up location again.
>>>
>>> The behavior is not exactly the same as you requested, as first branch
>>> is canceled. But given that the branch will be called again in short
>>> time, the user might not notice anything in terms of ringing interruption.
>> The problem may be that there is a missed called on device 1. Maybe this
>> can be avoided by adding the reason header with "cause=200" if the
>> client supports it.
> That is a good idea - but how do you add that to a CANCEL generated
> by Kamailio using this function?
There is support for reason header in CANCEL generated by TM -- not sure 
it is done for this case but should not be a big patch, as the same 
internal function is executed to send this cancel (a parameter should be 
set for the reason header, iirc).

Cheers,
Daniel

-- 
Daniel-Constantin Mierla - http://www.asipto.com
http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda