Open a web browser like internet explorer or Netscape.

Enter the ip address of your router in the address bar of your browser. In the picture above the address bar has http://www.google.com in it. Just replace all of that with the ip address of your router. By default the ip address should be set to 192.168.0.1.

You should see a box prompting you for your username and password. Enter your username and password now. By default the username is admin, and the password is blank. Click the Ok button to log in to your router.

The next screen that appears is the Main Menu. Click Advanced at the top of the screen.

Now you should be looking at the Advanced Menu. Click Applications in the menu on the left.

Put the name of the service in the name box. It doesn't really matter what the name is. You could call it "daffy duck" if you wanted to. Specify the trigger ports in the trigger ports boxes. The software you are trying to run should give you the details of what these should be. Select the trigger type. Put the list of ports that you want to forward into the public port box. You should separate these with a comma in the case of nonsequential ports(50,55,60), or by a dash if you want to list a series of ports(50-60). Select the public port type. Put a dot in the enable section to enable the port triggering config you just made. Lastly click Apply to save your changes.

You should save your settings and restart the router to make sure the settings take effect. It is also a good idea to make sure that the ports you have forwarded are allowed through your firewall.