In enterprises, the gateway node often acts as a proxy server and a firewall. The gateway is also associated with both a router, which use headers and forwarding tables to determine where packets are sent, and a switch, which provides the actual path for the packet in and out of the gateway.

(2) A computer system located on earth that switches data signals and voice signals between satellites and terrestrial networks.

(3) An earlier term for router, though now obsolete in this sense as router is commonly used.

Yahoo!'s World Wide Web gateways page
Yahoo!'s directory of World Wide Web gateway information.

Stopping Spam at the Gateway
Bandwidth-sapping spam is more than an annoyance; it's increasingly becoming a drain on the bottom line. Fortunately, administrators can fight back with technology that yields cleaner inboxes and fewer mail server meltdowns.