Simple Port Forwarding
If your home router is mulishly refusing to work with certain Internet applications, such as online gaming, you may need Simple Port Forwarding. Home routers are deceptively simple to install, and sometimes maddeningly difficult to administer. This free program can help you solve one very specific problem they present with the use of certain applications.
Some Internet applications, particularly games, require that a specific Internet port--a virtual port, not a physical one--be accessed in order for the application to work. The problem is that the PCs inside your home network don't have their ports exposed to the Internet; they're shielded by your router.
The answer? Port forwarding, in which when a certain application from the Internet needs to contact a port, the router forwards that request to the proper computer on your home network. Doing this yourself, manually, using your router's setup can be maddeningly difficult. That's where Simple Port Forwarding comes in. Run the program, tell it which ports to forward to which PC, and your work is done.
Note: This program is donationware. It is free to try, but the author accepts and encourages donations towards further development.