VoIP/(802.11g) Broadband Firewall Router
Chapter 4: Configuration
Virtual Server (“Port Forwarding”)
In TCP/IP and UDP networks a port is a 16-bit number used to identify which application program (usually
a server) incoming connections should be delivered to. Some ports have numbers that are pre-assigned
to them by the IANA (the Internet Assigned Numbers Authority), and these are referred to as “well-known
ports”. Servers follow the well-known port assignments so clients can locate them.
If you wish to run a server on your network that can be accessed from the WAN (i.e. from other machines
on the Internet that are outside your local network), or any application that can accept incoming
connections (e.g. Peer-to-peer/P2P software such as instant messaging applications and P2P file-sharing
applications) and are using NAT (Network Address Translation), then you will usually need to configure
your router to forward these incoming connection attempts using specific ports to the PC on your network
running the application. You will also need to use port forwarding if you want to host an online game
server.
The reason for this is that when using NAT, your publicly accessible IP address will be used by and point
to your router, which then needs to deliver all traffic to the private IP addresses used by your PCs. Please
see the
WAN
configuration section of this manual for more information on NAT.
The device can be configured as a virtual server so that remote users accessing services such as Web or
FTP services via the public (WAN) IP address can be automatically redirected to local servers in the LAN
network. Depending on the requested service (TCP/UDP port number), the device redirects the external
service request to the appropriate server within the LAN network
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