[Kamailio-Users] STUN and TM

[Daniel-Constantin Mierla]

Hello,

On 01/30/2009 09:00 AM, Jason Penton wrote:
> Hi *,
>
> What is the logic behind the transation matching in Kamailio. I am 
> finding a problem whereby a call setup transaction (INVITE, 180 
> Ringing, PRACK, 200OK, ACK). between 2 Snom phones works in normal 
> mode. However, when one phone is behind a NAT with STUN support, 
> everything works perfectly (i.e. call setup, 2-way audio, etc), BUT 
> the tm module doesnt match the transaction between the original invite 
> and the subsequent messages (180, 200ok, etc). the impact here is that 
> the fr_inv_timer eventually fires even though the call has been 
> answered. Note: this only happens when the call is destined for the 
> device behind the NAT.
>
> Any ideas.
>
> Perhaps an explanation on how the tm module does transaction manager.
>
> RFC3261 states that transaction matching is done based on the via 
> branch parameter.
it is the way tm does it. Can you paste the sip trace of such situation? 
It will help to troubleshoot.

Cheers,
Daniel

-- 
Daniel-Constantin Mierla
http://www.asipto.com