[Kamailio-Users] fr_inv_timer increased to 120 secs

[Klaus Darilion]

Iñaki Baz Castillo wrote:
> El Lunes, 11 de Agosto de 2008, Kaeman Chris escribió:
>> Hello,
>>
>> What are the problems in production that can be encountered if the
>> fr_inv_timer is increased from 30-45 secs to 120 secs for a sip-sip call?
>> Anyone have found any issues?
> 
> In fact, I recommend you to use a value greater then 100 seconds (at last).
> fr_inv_timer is the time OpenSer keeps the transaction until it receives a 
> final response, but note A can call B and B rings for more than fr_inv_timer 
> before send a 200 OK. What will occur then? OpenSer will receive the 200 OK 
> and will drop it since transaction was already deleted.

Kamailio never drops final responses (even if you call "drop" in the 
reply route) - they will get forwarded stateless if no corresponding 
transcation is not found (timed out).

Further, if there was at least one provisional response (e.g 100) then 
Kamailio will send a CANCEL, thus in this case there should be no 200 OK 
after transaction timeout.

regards
klaus

> 
> So set always fr_inv_timer greater than 100 seconds. In fact, there is not any 
> issue if you set a value os 300 seconds (usually 99% of calls are not ringing 
> for more than 60 seconds).
>