I will explain our current setup so as to try and help you understand what we are trying to achieve.
We have a server 2008 machine on our internal network that has the server version of our server on it.
We then have 40 test machines on a separate network with it's own separate internet connection. These all have the client version of our software on. They then have a VPN connection that connects them to the server 2008 machine.
We can run multiple versions of the client on each of the test machines. Everything works fine until the number of clients connected reaches 500, then the software just crashes.
Is this likely to be a problem with our software or more likely to be a limitation on the number of incoming connections the server 2008 machine can receive. Port limit etc?
Any help would be great