Answering to myself: the I-CSCF routing logic contains a “append_branch()” on reception of the HSS LIR answer which is the cause of this use less fork

Removed it and everything is fine

Olivier

De : sr-users-bounces@lists.sip-router.org [mailto:sr-users-bounces@lists.sip-router.org] De la part de DURECU, OLIVIER (OLIVIER)
Envoyé : vendredi 21 mars 2014 17:39
À : sr-users@lists.sip-router.org
Objet : [SR-Users] Kamailio ICSCF strange forking

Hi all,

I have deployed an IMS based on Kamailio 4.1.2 and I don’t manage establishing a call.

Users registration is OK but when I initiate the call from A@ims.net to B@ims.net, I notice a strange I-CSCF behavior

The INVITE message goes OK from P-CSCF to S-CSCF then to I-CSCF. Till this point everything is fine…

Then the I-CSCF performs its LIR diameter request and gets an Ok response from the HSS with a S-CSCF URI

The I-CSCF forwards the INVITE at the received S-CSCF.

BUT at the same time the I-CSCF generates a DNS request to resolve ims.net SIP SRV (it gets itself as answer…) and forwards a second INVITE (exact copy from the one sent to the S-CSCF) to itself

So I have 2 copies of the same INVITE dialog travelling in the network and messing everything.

Any idea of the cause of this behavior .

Thanks for your support…

Olivier