Virtual Servers - 3Com OfficeConnect 3CRWDR100B-72 User Manual

If your application is not listed, you will need to check with the
application vendor to determine which ports need to be configured. You
can manually input this port information into the Router. To do this:
1 Specify the trigger port (the one used by the application when it is
initialized) in the Trigger Port column, and specify whether the trigger is
TCP or UDP.
2 Specify the Public Ports used by the application, that will need to be
opened up in the firewall for the application to work properly. Also
specify whether these ports are TCP or UDP.
3 Click Apply.

Virtual Servers

Figure 50 Virtual Servers Screen
This function allows you to route external (Internet) calls for services such
as a web server (port 80), FTP server (Port 21), or other applications
through your Router to your internal network. Since your internal
computers are protected by a firewall, machines from the Internet cannot
get to them because they cannot be 'seen'.
If you need to configure the Virtual Server function for a specific
application, you will need to contact the application vendor to find out
which port settings you need.
Firewall 61