Axiom and NAT/Port Forwarding

Hi All, 

Having an issue with loading the Axiom UI. Users connecting from outside the network are unable to load Axiom but it works fine for users on the network. 

The external user traffic is going through a firewall which is performing NAT (private IP address mapped to public)  and port forwarding (Axiom webserver port mapped to external port).

Has anyone experienced similar issues? Are there any special settings required to get Axiom working over a firewall?