I have 2008 server with 2NICS. primary card is 192.168.44.249 with default gateway pointing to 192.168.44.1 (DSL Router/FireWall) secondy card is 192.168.88.249 with default gateway pointing to 192.168.88.1 (DSL Router/FireWall) when a call is made the phone system routes via 44.1 but I want it to go via 88.1 both routers have fixed ip addresses. 3cx is setup with stun. if I turn stun off and set the intefarce ip and external address it works when i use 44.1 and it's public ip, but not when is use 88.1 interface and it's public ip. Therefore, I assume all routes are being sent via the default gateway of the primary nic. I can't find a setting for 3cx to use a specific interface for a SIP trunk.