Which layer is responsible for maintaining and terminating communication sessions, i.e., session state management?

• A. Layer 4 Transport
• B. Layer 5 Session
• C. Layer 2 Data Link
• D. Layer 6 Presentation

Answer: (B)

Managing the lifecycle of a communication with another application—establishing, maintaining through the dialogue, and terminating the session—is handled by the session layer. This layer is responsible for initiating sessions, keeping them coordinated, and closing them when the interaction ends, including features like dialog control and synchronization points so both ends stay in sync during the conversation. The transport layer deals with delivering data end-to-end and handling reliability and flow control, but it doesn’t manage the session’s lifetime. The data link layer focuses on framing and access to the local network segment, while the presentation layer handles how data is formatted and encrypted. So, the session layer best fits the idea of session state management.