If you have a router at home or your office, you will need to forward ports in
order for outside traffic to get into your network. Think of your router as being a
huge electric fence or wall, with a few doors or openings. This fence serves as your
barrier from the scary outside Internet world. Your router comes pre-configured with a
few of those doors (or ports) open to let you access the internet, but the others are
closed tight. So, in order to run a mail server, game server, access your computer
remotely, etc you will need to open an extra door or two in your router in order for
the outside traffic to get inside. This is called Port Forwarding.
Check out our General Port forwarding Guide for more
information.