Nat; Virtual Server - Edimax BR-6524n Manual

3-5-2 NAT

Network address translations solve the problem if sharing a single IP
address to multiple computers. Without NAT, all computers must be
assigned with a valid Internet IP address to get connected to Internet, but
Internet service providers only provide very few IP addresses to every
user. Therefore it's necessary to use NAT technology to share a single
Internet IP address to multiple computers on local network, so everyone
can get connected to Internet.
This broadband router supports four types of NAT functions, and the
instructions of these functions will be given below.

3-5-2-1 Virtual Server

This function allows you to redirect a port on Internet IP address (on
WAN port) to a specified port of an IP address on local network, so you
can setup an Internet service on the computer on local network, without
exposing it on Internet directly. You can also build many sets of port
redirection, to provide many different Internet services on different local
computers via a single Internet IP address.