[SR-Users] How do deal with a lost ACK and TM

[Klaus Darilion]

Hi!

TM only handles retransmissions of single transaction.

The ACK is a new transaction, thus there won't be any retransmissions by 
tm. tm will forward the retransmitted 200 OK and the client should 
retransmit ACK.

Maybe you have a problem with NATs and the ACK is routing falsely. Take 
a look at the request URI of the ACK - it should contain Asterisk's IP 
address.

regards
Klaus



Am 21.06.2010 15:12, schrieb Geoffrey Mina:
> I am not 100% sure I fully understand my issue, but I think I'm on the
> right track.  I have a situation where Asterisk will drop calls a few
> seconds after they are set up.  What I believe is happening:
>
> a=asterisk
> k=kamailio
>
> k --> INVITE --> a
> a --> 100 TRYING --> k
> a --> 183 RINGING --> k
> a --> 200 OK --> k
> k --> ACK -->a (this packet is never received by asterisk)
> a --> 200 OK (retransmit) -->k
> a --> 200 OK (retransmit) -->k
> a --> 200 OK (retransmit) -->k
> a --> no response to critical packet - terminating call
>
>
> It doesn't appear that Kamailio is retransmitting the ACK.  I would
> think that would be part of the TM module, but perhaps I am not using it
> properly.  Is this possible or is there something else going on?
>
> Thanks.
>
>
>
> _______________________________________________
> 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