The Port Range Forwarding screen sets up public services on your network, such as web servers, ftp servers, e-mail servers, or other specialized Internet applications. (Specialized Internet applications are any applications that use Internet access to perform functions such as videoconferencing or online gaming. Some Internet applications may not require any forwarding.)
When users send this type of request to your network via the Internet, the Router will forward those requests to the appropriate PC. Any PC whose port is being forwarded to must have a static IP address, either by having its DHCP client function disabled, or by having a static DHCP entry defined (see DHCPd for help on this). Using a dynamic IP address is not recommended, as its IP may change.
One page links to SV-ApplicationGaming-PortForwarding: