[SR-Users] kamailio 4.0.3 - contact header in ACK

Daniel-Constantin Mierla miconda at gmail.com
Wed Nov 27 23:30:28 CET 2013


For further clarification, the Contact header is not relevant at all (so 
not used) for routing current request (no matter is ACK or something 
else). No Contact never results in misrouting. As Alex pointed, only a 
full sip trace can reveal the problem.

Cheers,
Daniel

On 11/27/13 8:31 PM, Alex Balashov wrote:
> The only way to diagnose this is to get a full packet capture. In all 
> likelihood, there is a problem with the ACK. 4.0 does not, in 
> principle, mishandle ACKs, no, but loose-routing and NAT problems 
> related to their handling are not uncommon.
>
>
> Adnan <112linuxstockholm at gmail.com> wrote:
>
>     Hi,
>
>     We are migrating from our openser 1.4 to kamailio 4.0.3 and have
>     run into a couple of issues. One of them is described below and we
>     need to know if it is a known bug or not.
>
>     Kamailio receives an INVITE from a gateway and finally responds
>     with 200 OK. Then an ACK is generated by the gateway towards the
>     Kamailio that some how does not get relayed to the next hop.
>
>     The only special aspect here is that the ACK does not contain a
>     Contact header. Is that something that could confuse kamailio and
>     make it unable to relay?
>
>     According to SIP RFC, a contact header in ACK is not a must have.
>     Our case is the one where ACK  is sent by the UAC after receiving
>     a 200 OK final response. Everything else about the ACK looks OK
>     e.g. ACK has a branch different from the the branch value in the
>     UAC INVITE.
>
>     Is it a a known bug in 4.0.3?
>
>     In the configuration, we handle ACK as below:
>
>     if (is_method("ACK")) {
>                                     if (t_check_trans()) {
>                                             t_relay();
>                                             exit;
>                                     } else {
>                                             exit;
>                                     }
>     Br
>     Adnan
>
>     ------------------------------------------------------------------------
>
>     SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
>     sr-users at lists.sip-router.org
>     http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
>
>
> --
> Sent from my mobile, and thus lacking in the refinement one might 
> expect from a fully fledged keyboard.
>
> Alex Balashov - Principal
> Evariste Systems LLC
> 235 E Ponce de Leon Ave
> Suite 106
> Decatur, GA 30030
> United States
> Tel: +1-678-954-0671
> Web: http://www.evaristesys.com/, http://www.alexbalashov.com
>
>
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-- 
Daniel-Constantin Mierla - http://www.asipto.com
http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda

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