We've run into issue after issue due to our firewall. Not just the ports being open but also the NAT (Network address Translation). For example, with stored processes, when the spawner fires up a stored process server it was referencing it using the servers internal IP address. The client (outside the firewall) couldn't see the server's internal IP address. There was a fix for this. But we still have a problem with Information Map studio when we attempt to access data from outside the firewall (can't test the map or create filters or expressions.)