Which layer establishes and manages communication sessions between hosts?

Which layer establishes and manages communication sessions between hosts?

• A. Network Layer
• B. Data Link Layer
• C. Application Layer
• D. Session Layer

Answer: (D)

Session management is about establishing, maintaining, and terminating conversations between applications on different hosts. The layer that handles this in the OSI model is the one dedicated to managing those communication sessions. It sets up the dialogue, negotiates how data will be exchanged (such as whether the session is half- or full-duplex), and keeps the session synchronized with checkpoints so long transfers can resume if there’s an interruption. This layer also coordinates the dialogue to ensure orderly communication between the two ends. The other layers handle different responsibilities: the Network Layer is responsible for routing packets between networks, the Data Link Layer takes care of framing and error detection on a single link, and the Application Layer provides services directly to user-facing applications. In the OSI view, those roles are separate from the session-focused coordination and control that the Session Layer provides.

Session management is about establishing, maintaining, and terminating conversations between applications on different hosts. The layer that handles this in the OSI model is the one dedicated to managing those communication sessions. It sets up the dialogue, negotiates how data will be exchanged (such as whether the session is half- or full-duplex), and keeps the session synchronized with checkpoints so long transfers can resume if there’s an interruption. This layer also coordinates the dialogue to ensure orderly communication between the two ends.

The other layers handle different responsibilities: the Network Layer is responsible for routing packets between networks, the Data Link Layer takes care of framing and error detection on a single link, and the Application Layer provides services directly to user-facing applications. In the OSI view, those roles are separate from the session-focused coordination and control that the Session Layer provides.