Definition: An application gateway is a type of firewall. All internal computers establish a connection with the proxy server. The proxy server performs all communications with the Internet. External computers only see the IP address of the proxy server and never communicate directly with the internal clients. The application gateway examines the packets more thoroughly than a circuit-level gateway when making forwarding decisions. It is considered more secure, but uses more memory and processor resources.
Also Known As: Application Proxy, Application-Level Proxy