Some applications such as Internet gaming, video-conferencing, and Internet telephony, require multiple connections. These applications may not work when Network Address Translation (NAT) is enabled. If you need to run applications that require multiple connections, use these pages to specify the additional public ports to be opened for each application.
To use the preset values available on your router:
If you cannot find your application in the list of popular applications, try the List of well known special applications link below the Public Port heading.