1. Still wondering... 2.[SER]---[NAT]<----> dial.mine.nu <----->[Clients] I have an old p233 machine with 2st eth-cards if there is any advantage to set up a Linux-router insted of my us-robotics NAT-firewall it is possible. Note: It is only for the hosting of the SER server. In that case some iptables/SIP-hints would be nice :) Regarding the connectiontest witch i preformed with kphone. Internal case: both sending and reciving states External case: Just sending case.....retrying but no responce from SER.