Unfortunately, there is no information about the software in question. I have checked the official website, but no download or trace about iPort was available. You now have 3 possible ways out:
Contact the developers and ask them information about the software and its working requirements/conditions.
Enable the UPnP feature on the router, which will automatically open the port when necessary.
Use TCPView. Open the application, then start iPort, and check the PORTS that are opened. Use the ports on the Port Forwarding on the router's interface and assign the IP. That's it.