[SR-Users] Solution for Invite retransmission

[Daniel-Constantin Mierla]

Alex' suggestions about investigating further the cause are good.

What I wanted to say is the if dialog module is used only for this
purpose, then you can look at implementing a similar check with htable,
the key can be:

$ci:$cs:$ft

respectively the call id, cseq and from tag. Of course guarded to see it
is an invite with no to-tag.

If you want to be even more strict, in case of parallel forking from
upstream, you can add top via branch to the key.

Cheers,
Daniel

On 13.05.20 04:29, Alex Balashov wrote:
> I would look to learn more about the ultimate cause of retransmissions
> arriving beyond the life cycle of the transaction in Kamailio, as it
> seems to possibly portend of a bigger problem.
>
> However, if the issue is one of retransmissions arriving just beyond the
> expiration of Kamailio's transaction lifetime holddown timers, you can
> tweak those:
>
> https://kamailio.org/docs/modules/5.3.x/modules/tm.html#tm.p.wt_timer
>
> https://kamailio.org/docs/modules/5.3.x/modules/tm.html#tm.p.max_inv_lifetime
>
> -- Alex
>
> On Tue, May 12, 2020 at 05:15:15PM +0100, Duarte Rocha wrote:
>
>> Greetings,
>>
>> I have an issue where a client doesn't get the responses to the INVITE sent
>> and as such keeps sending me retransmissions of the INVITE.
>>
>> While the transaction is still up, Kamailio does its job. However, when the
>> transaction is closed Kamailio processes the request again as a first
>> request (Doing Routing and Dispatcher operations again).
>>
>> In order to avoid the issue i've made the following code :
>>
>>     // If it's the first INVITE
>>  if( is_method("INVITE") && !has_totag() )
>>  {
>>   if(t_check_trans()) {
>>             xnotice("TRANS - INVITE Retransmission");
>>         }
>>         else if ( is_known_dlg()) {
>>             xerr("KamTAG: INVITE in dialog without To Tag ");
>>             exit;
>>         }
>>     }
>>
>> Is this a good solution and still compliant with the SIP rules?
>>
>> Best Regards
>> _______________________________________________
>> Kamailio (SER) - Users Mailing List
>> sr-users at lists.kamailio.org
>> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
>
> -- 
> Alex Balashov | Principal | Evariste Systems LLC
>
> Tel: +1-706-510-6800 / +1-800-250-5920 (toll-free) 
> Web: http://www.evaristesys.com/, http://www.csrpswitch.com/
>
> _______________________________________________
> Kamailio (SER) - Users Mailing List
> sr-users at lists.kamailio.org
> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users

-- 
Daniel-Constantin Mierla -- www.asipto.com
www.twitter.com/miconda -- www.linkedin.com/in/miconda
Funding: https://www.paypal.me/dcmierla