FUNDAMENTALS OF COMPUTER

Detailed explanation-1: -Circuit-level proxies operate at Layer 5 (session), and are below application-layer proxies (at Layer 7). This allows them to filter more protocols: There is no need to understand each one; the application-layer data is simply passed along.

Detailed explanation-2: -–Circuit-level proxy Operates at the Session Layer of the OSI Model and makes access decisions based on address, port and protocol type, and not on the packet content.

Detailed explanation-3: -A circuit-level proxy is one that creates a circuit between the client and the server without interpreting the application protocol. The most extreme version of an application-level proxy is an application like Sendmail, which implements a store-and-forward protocol.

Detailed explanation-4: -Layer 5 of the OSI Model: Session Layer is the layer of the ISO Open Systems Interconnection (OSI) model that controls the dialogues (connections) between computers. It establishes, manages, and terminates the connections between the local and remote application.

Detailed explanation-5: -The OSI Model is a conceptual framework used to describe the functions of a networking system. The proxy firewall acts as an intermediary between two systems. It protects the network by filtering traffic at the application layer. A proxy firewall is also be called a gateway or application firewall.