I hope this will be useful
These routers do port forwarding by assigning port numbers to a "service" that is associated with the application you want to run.
To Let an Application Use Port Forwarding
1. Type the router's address in an Internet browser's address bar. (By default the router's address is 192.168.0.1). The Setup Wizard appears.
2. Enter the router's username and password.
3. Under Advanced, click Port Forwarding on the left menu bar.
A Port Forwarding Screen (Varies Slightly by Router)
4. From the Service & Game (or Service Name) pull down, select the service that you will host. The services the router knows about are listed here. If the service does not appear in the drop down, add a service as described in the next section, then return to this step.
5. Enter the IP address of your local server in the Server IP Address box.
6. Click Add.
7. Click Logout to exit from router settings.
To Add a Service for These Routers
To define a service not in the Service Name list, determine what port numbers are used by the service.
1. Click Add Custom Service.
2. Enter the first port number in an unused Start Port box.
3. If only one port number is to be forwarded, enter the same number in End Port. To specify a range of ports, enter the last port to be forwarded in the End Port box.
4. Enter any name you choose for the service.
5. Click Apply.