Find "Port Forwarding"
Click Internet.
Click Port Forwarding.
Set up new port mapping
Click New port mapping.
Highlight the field next to "Mapping name" and key in the required name.
Click Add port mapping application.
Click Add port application.
Highlight the field next to "Name" and key in the required name.
Enter external port numbers
Highlight the fields next to "External port" and key in the required interval.
To forward a single port, you need to key in the same port number in both fields.
Enter internal port number
Highlight the field next to "Internal port" and key in the port number of the device to which the external port numbers are to be forwarded.
Select protocol
Click the drop down list next to "Protocol".
Highlight the required protocol.
Click Save.
Click the close icon.
Enter internal IP address
Click the drop down list next to "Application".
Highlight the mapping name you've just set up.
Click the drop down list next to "Internal host".
Highlight the device to which the external port numbers are to be forwarded.
Save mapping
Click Save.