DMZ (Demilitarized Zone) option lets you set a single computer on your
network outside of the router. If you have a computer that cannot run
Internet applications successfully from behind the router, then you can
place the computer into the DMZ for unrestricted Internet access.
Putting a computer in the DMZ may expose that computer to a variety of
security risks. Use of this option is only recommended as a last resort.
Application Level Gateway (ALG) Configuration