Hi I need help on NAT with Kamailio... My Network Details are as follows... SIP Phone Registration ADSL Router Kamailio Asterisk 172.18.100.73/255.255.0.0 192.168.1.1/255.255.255.0 192.168.1.68/255.255.255.0 192.168.1.70/255.255.255.0 172.18.100.72/255.255.0.0 GW: 172.18.100.72 (Virtual IP 172.18.100.68) (Virtual IP 172.18.100.70) Router Type: AirLink 101 802.11 Token Ring Where Virtual IP 172.18.100.68 and 172.18.100.70 set virtually on ADSL Router.. and set routing on it.. So when I ping 172.18.100.70 it will go through 192.168.1.1 I am able to call, receive means able to receive OK, INVITE and REGISTER method of kamailio ... but When i try to Hangup call, it can't hangup at both side.. I have to manually cut phone at the other end.. I have not set any rule on Router. *Scenario...* 1] I have two user. 1212(a)domain.com [172.18.100.73] and 2121(a)domain.com[172.18.100.72] and register successfully 2] Call from 1212(a)domain.com [172.18.100.73] to 2121(a)domain.com[172.18.100.72].. 3] Call is connected successfully 4] While hangup from 1212(a)domain.com [172.18.100.73] it will take time and at the other end, I have to manually hangup call.. Please help me out.. -- Regards, Chandrakant Solanki