3Com 3CRWE754G72-A - Manual (Page 61)

Firewall 61
■ Remote Admin
Figure 49 Advanced Screen
NAT Enable
Before you enable this function, make sure you have changed the
administrator password. Network Address Translation (NAT) is the
method by which the router shares the single IP address assigned by your
ISP with the computers on your network. This function should only be
used by advanced users, and if your ISP assigns you multiple IP addresses
or you need NAT disabled for an advanced system configuration. If you
have a single IP address and you turn NAT off, the computers on your
network will not be able to access the Internet. Other problems may also
occur.
Universal Plug and Play
Universal Plug and Play is a technology that offers seamless operation of
voice messaging, video messaging, games, and other applications that
are Universal Plug and Play compliant. Some applications require the
Router's firewall to be configured in a specific way to operate properly.
This usually requires opening TCP and UDP ports and in some instances
setting trigger ports. An application that is Universal Plug and Play
compliant has the ability to communicate with the Router, basically
"telling" the Router which way it needs the firewall configured. The