BEC 8800N User Manual page 71

External Port Start / External Port End: Enter the public port number & range you wish to
configure.
Protocol: In addition to specifying the port number used, you also need to specify the protocol
used. The protocol is determined by a particular application. Most applications use TCP or UDP,
however you may also specify other protocols using the drop-down Protocol menu.
Internal Port Start / Internal Port End: Enter the public port number & range you wish to
configure.
Click Apply/Save to confirm the settings and you will be returned to Port Mapping table.
Remove: To delete the port mapping entry from the table, check Remove checkbox then click
Remove button to delete the selected item.
Since NAT acts as a "natural" Internet firewall, your router protects your network from accessed
by outside users, as all incoming connection attempts point to your router unless you specifically
create Virtual Server entries to forward those ports to a PC on your network. When your router
needs to allow outside users to access internal servers, e.g. a web server, FTP server, Email
server or game server, the router can act as a "virtual server". You can set up a local server with
a specific port number for the service to use, e.g. web/HTTP (port 80), FTP (port 21), Telnet (port
23), SMTP (port 25), or POP3 (port 110). When an incoming access request the router for a
specified port is received, it is forwarded to the corresponding internal server.
For example, if you set the port number 80 (Web/HTTP) to be mapped to the IP Address
192.168.1.2, then all incoming HTTP requests from outside users are forwarded to the local server
(PC) with the IP address of 192.168.1.2. If the port is not listed as a predefined application, you
need to add it manually.
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