Daniel, Not, those IP are in a different subnet. There is a firewall - running on a different device. Ping and SIP Messages are going very well from 2.2.2.2 to 8.8.8.8. I was able to solve this issue by disabling mhomed and set "listen" external interface with IP address 2.2.2.2 on top in the configuration file. Now, Kamailio is starting without any errors and is registering to the upstream provider, but I just I am wondering if it's possible to specify an outgoing socket for uac module in the configuration file? Thank you.