Dear list further to the above problem i observed the following:

ACK message coming from PABX1:

U +0.001877 192.168.10.189:5060 -> 81.21.38.34:5060
ACK sip:94294294@81.21.38.55 SIP/2.0*
Via: SIP/2.0/UDP 192.168.10.189:5060;branch=z9hG4bK76f8f103;rport*
Route: <sip:81.21.38.34;lr=on;ftag=as181922af;did=c83.f641>,<sip:94294294@81.21.38.5;pgw-call=call-2aa6>,<sip:81.21.38.34;lr=on;ftag=as181922af>*
Max-Forwards: 70*
From: "22498045" <sip:22498045@192.168.10.189>;tag=as181922af*
To: <sip:94294294@81.21.38.34>;tag=3d95248-37261551-13c4-50022-1c3096-5cc2673d-1c3096*
Contact: <sip:22498045@192.168.10.189:5060>*
Call-ID: 696cfa577f42395767bc812e7e8a38a5@192.168.10.189:5060*
CSeq: 102 ACK*
User-Agent: FPBX-2.8.1(1.8.21.0)*
Content-Length: 0*



ACK message sent to PGW from Kamailio1

U +0.001254 81.21.38.34:5060 -> 81.21.38.5:5060
ACK sip:94294294@81.21.38.55 SIP/2.0*
Via: SIP/2.0/UDP 81.21.38.34;branch=z9hG4bKc526.9402c2edbc3ef96d9e405408364506a9.0*
Via: SIP/2.0/UDP 192.168.10.189:5060;branch=z9hG4bK76f8f103;rport=5060*
Route: <sip:94294294@81.21.38.5;pgw-call=call-2aa6>,<sip:81.21.38.34;lr=on;ftag=as181922af>*
Max-Forwards: 16*
From: "22498045" <sip:22498045@192.168.10.189>;tag=as181922af*
To: <sip:94294294@81.21.38.34>;tag=3d95248-37261551-13c4-50022-1c3096-5cc2673d-1c3096*
Contact: <sip:22498045@192.168.10.189:5060>*
Call-ID: 696cfa577f42395767bc812e7e8a38a5@192.168.10.189:5060*
CSeq: 102 ACK*
User-Agent: FPBX-2.8.1(1.8.21.0)*
Content-Length: 0*




Shouldn't the ACK  message to the PGW have the header ACK sip:94294294@81.21.38.5;pgw-call=call-2aa6 and the Route: <sip:81.21.38.34;lr=on;ftag=as181922af>*   ???




Your help is much appreciated!!

Phillip



On Thu, Jun 6, 2013 at 12:26 PM, phillman25 <phillman25@gmail.com> wrote:
Dear List

I upgraded from Kamailio v 3.3 to 4.0.1 and am now facing an issue for the below scenario:

PABX1 ==> Kamailio1 ==> Cisco PGW ==> Kamailio1 ==> PABX2


I understand that this is a hairpin scenario but was working normally on v 3.3.

Checking in the syslog i see:
ERROR: <core> [receive.c:230]: ERROR: receive_msg: no via found in reply

Checking the sip trace i see that when calling from PABX1 to PABX2. After PABX2 answers and the the 200 OK  is eventually sent  to PABX1 , PABX1 answers with ACK but seems like its not sent back to PABX2  as a result PABX resends a 200 OK and the cycle continues until PABX2 sends a BYE message. Please see below the ACK received from PABX1:

ACK sip:94294294@81.21.38.55 SIP/2.0
Via: SIP/2.0/UDP 192.168.10.189:5060;branch=z9hG4bK6bffe37c;rport
Route: <sip:81.21.38.34;lr=on;ftag=as1cd4f8f1;did=e36.c471>,<sip:94294294@81.21.38.5;pgw-call=call-26eb>,<sip:81.21.38.34;lr=on;ftag=as1cd4f8f1>
Max-Forwards: 70
From: "22498045" <sip:22498045@192.168.10.189>;tag=as1cd4f8f1
To: <sip:94294294@81.21.38.34>;tag=3d94f08-37261551-13c4-50022-1c1e67-87fe958-1c1e67
Contact: <sip:22498045@192.168.10.189:5060>
Call-ID: 03042a717e27a87e759f7f4879e70377@192.168.10.189:5060
CSeq: 102 ACK
User-Agent: FPBX-2.8.1(1.8.21.0)
Content-Length: 0


Is there an issue with the above ACK message? Is there any way to solve this issue quickly perhaps by disabling loose route?
I have observed that this issue occurs only when hairpinned. 


Thanking you in advance!

Phillip