Gateways

Application gateways

An application gateway is a hardware/software system for connecting two networks together, in order to serve as an interface between different network protocols.

When a remote user contacts the gateway, it examines his/her request; if that request corresponds to the rules that the network administrator has set, the gateway creates a link between the two networks. The information, therefore, is not directly transmitted; rather, it is translated in order to ensure continuity between the two protocols.

Besides an interface between two different kinds of networks, this system offers additional security, as all information is carefully inspected (which may cause a delay) and is sometimes recorded in an event log.

The major drawback of this system is that there must be an application of this kind available for each service (FTP, HTTP, Telnet, etc.).