[SR-Users] Kamailio: 500 Server error occurred (19/SL).

[Daniel-Constantin Mierla]

Hello,

On 7/13/11 5:51 PM, Max Doronin wrote:
> Hello guys,
>
> I have strange behavior on my Kamailio-1.5.1-notls instance.
>
> I have LCR and TM modules enabled.For a particular destination I have
> 4 routes to try. When I call to non-existing number, it tries
> - route 1 (404 Not Found)
> - route 2 (404 Not Found)
> - route 3 (503 Service unavailable)
>
> And the problem is with the last 503.
>
> Kamailio ACKs it, immediately drops these 2 lines into syslog
> Jul 13 04:14:47 /usr/local/sbin/kamailio[23572]:
> ERROR:tm:t_forward_nonack: no branch for forwarding
> Jul 13 04:14:47 /usr/local/sbin/kamailio[23572]: ERROR:tm:w_t_relay:
> t_forward_nonack failed
> And sends
> SIP/2.0 500 Server error occurred (19/SL).
> To the call originator.
>
> 30 microseconds later it sends
> SIP/2.0 500 Service Unavailable.
> to the originator again
>
> Latter 500 looks like the relayed original "503 Service unavailable".
> I think so because the Reason header is the same:
> Reason: SIP;cause=503;text="Service
> Unavailable";icodetext="NoCircuitAvailable";iintcode=10034;isubsystem=3.
>
> Obviously call is terminated.
>
> I noticed that that last peer rewrites my Via headers like this:
> Original:
> ==
> Via: SIP/2.0/UDP 187.45.214.132;branch=z9hG4bK3dac.fae9b793.2.
> Via: SIP/2.0/UDP
> 192.168.2.33:5622;received=49.49.59.23;branch=z9hG4bK-d8754z-a6ba40014f97fb7c-1---d8754z-;rport=23832.
> ==
>
> Rewritten
> ==
> Via: SIP/2.0/UDP
> 187.45.214.132;received=187.45.214.132;branch=z9hG4bK3dac.fae9b793.2,SIP/2.0/UDP
> 192.168.2.33:5622;received=49.49.59.23;branch=z9hG4b
> ==
>
> I tried to modify via1_matching parameter (1 ->  0) but no changes.
>
> My questions are:
> - What can be the reason of that 500 with 19/SL
> - Can kamailio properly handle this 1 line Via header?
> - What can be the reason of that "t_forward_nonack: no branch for forwarding"?

it seems you try to forward one more time, but there is no new branch 
where to send. I guess there is some issue in the failure_route, like 
calling t_relay() even if the new branch is not added. If you can paste 
it here, I can tell more clear if something is wrong there.

Cheers,
Daniel

-- 
Daniel-Constantin Mierla -- http://www.asipto.com
Kamailio Advanced Training, Oct 10-13, Berlin: http://asipto.com/u/kat
http://linkedin.com/in/miconda -- http://twitter.com/miconda