Hi,
The easiest deployment for your EDGE server would be to assign 2 virtual network interfaces to the virtual machine. One that would connect to the public facing network and the other that would connect to your internal facing network.
This requires that your physical machine hosting the EDGE server would have 2 physical interfaces as each virtual network interface has to bind to a physical interface.
I don't know about your Firewall/NAT router but mine has a DMZ port on it which basically allows me to put a host on the internet without NAT which is good because then you get to least amount of issues as OCS requries a public IP directly routable without NAT to ensure that STUN (or Simple Traversal over UDP and NAT) works.
So assuming you have a DMZ port on your router this is where the physical interface that binds to the external facing virtual interface of my EDGE machine would connect to. The other physical interface would go into a regular switch that connects up to the other OCS Servers.
I hope this is somewhat clear :-)
Sincerely,
Tonino Bruno
