Which layer manages sessions between endpoints?

The Session Layer is responsible for managing sessions between endpoints in a network communication context. It establishes, maintains, and terminates connections between applications, ensuring that data exchange can occur seamlessly. This layer controls the dialogues (connections) between computers, providing services such as session establishment, maintenance, and termination, which are crucial for communication sessions to maintain state and manage data flow.

By managing the opening and closing of communication sessions, the Session Layer enables applications on different devices to coordinate their communications without requiring each device to handle those aspects individually. This includes handling issues such as session recovery and synchronization, ensuring that if a connection is interrupted, it can be resumed without losing any critical information.

The other layers, while vital in their specific roles, do not manage sessions in this way. The Network Layer is primarily concerned with routing data packets between devices, the Transport Layer is focused on the reliable transmission of data end-to-end, and the Physical Layer deals with the physical connections and transmission of raw bitstreams over a medium. Each layer has its specific functions, but only the Session Layer is tasked with maintaining the management of active sessions.