If you have a local client PC that cannot run an Internet application properly from behind the NAT firewall, then you can open the client up to unrestricted two-way Internet access by defining a virtual DMZ host.

Enable DMZ:     Yes   No

Multiple PCs can be exposed to the Internet for two-way communications such as Internet gaming, video conferencing, or VPN connections.  To use the DMZ, the client PC must have a static IP address.