Internal IP

Hi guys, normally i install fusion in a data center so it always has external ip address, however i am installing first one on site with internal ip and NAT , so for the most part all is well however if i try and register a phone extrnal form the network it wont register, says no domain and then extrnal ip ? if i use internal ip for system cant i have external users unless on vpn ?

hope that makes sense

Thanks
I
 
Your phones should register to a domain name (customer1.fusionpbx.com) which has a public DNS A record that points to the public IP address of your NAT firewall that your FusionPBX system is sitting behind.

Obviously you'll want the correct ports in your firewall pointing to the internal IP of your FusionPBX box, etc.