Hello, I need to set listen=0.0.0.0 in kamailio (because it's very important for me to add new IPs to my server without restarting kamailio), but I see that the Via header remains 0.0.0.0 in this case. So I added: advertised_address="my_ip_address" advertised_port=5060 Then I see that for normal calls the Via is set correclty but the problem still appears in nathelper. The OPTIONS sent by nathelper still uses 0.0.0.0 in the Via header. I tried: modparam("nathelper", "natping_socket", "my_ip_address:5060") modparam("nathelper", "force_socket", "my_ip_address:5060") but Via is still 0.0.0.0 Does anybody know what to do?