trunk gateway ip authentication

Hello, I have a Physical SIP Trunking from a Service Provider, Where they have given me a hardware with private IP. I am trying to register a gateway but i am unable to it. I have 2 Lan Cards, in one port i have the Lan with Internet Connection and on the other IP i have a direct line to the...

Good day ! Using Fusion 4.2 wanted to know if some one can help with instructions on how to set a gateway based on IP authentication. I am able to set them up via Registration but some providers require IP based trunk set up and we can not get it to work thx