Which layer of the OSI model is responsible for session management?

The layer of the OSI model responsible for session management is the Session Layer. This layer plays a critical role in establishing, maintaining, and terminating connections between applications that are running on different devices.

Session management involves taking care of dialogues between applications, coordinating communication between them, and handling the opening and closing of sessions. The Session Layer manages the flow of data, ensuring that sessions are maintained correctly and, if necessary, the information can be re-synchronized. It provides the necessary controls for establishing sessions, maintaining data exchange during the session, and gracefully ending the session when communication is complete.

While other layers have important roles—such as the Transport Layer, which handles end-to-end communication and error recovery, the Application Layer that interfaces directly with user applications, and the Data Link Layer which manages node-to-node communication and physical addressing—none of them are specifically responsible for managing sessions between applications. This specific functionality is the hallmark of the Session Layer in the OSI model.