Application Level Gateway

The other basic type of firewall is the session aware firewall. It is normally referred to as an application-level gateway. This is because it is not only session aware, but intimately familiar with the Internet applications that create sessions.

The application level gateway does more than just filter packets and sessions. It acts as a gateway between the protected network and the Internet.

A gateway is more than just a filtering device. It does not allow any packets to travel directly between the Internet and the protected network.