Hi All,

Looking for some help with a TCP issue in Kamailio.

I am running load testing through the proxy with a topology of UAC > Proxy > UAS.

With UDP it works fine (using SIPp scripts) - when I turn to TCP as the transport i get the following error in the kamailio logs:

ERROR: <core> [tcp_main.c:4159]: handle_tcpconn_ev(): connect 192.168.0.19:5060 failed

The IP address stated is the UAC which is sending an INVITE to the Proxy, which seems to send back a 100 TRYING to the UAC which is followed by repeated INVITE messages.

It looks like the leg from the Proxy to the UAS is never established using TCP - however if I send the SIP messages to the Proxy via TCP and set the UAS to receieve in UDP Kamailio completes with TCP > Kamailio > UDP.

When the UAC is set to send on TCP and UAS set to receive on TCP netstat shows the ports as listening.

Can anyone please help?