What is the primary function of Layer 2 in the OSI model?

The primary function of Layer 2 in the OSI model is focused on data-link layer functionalities, which include data framing and MAC (Media Access Control) or physical addressing. This layer is responsible for the node-to-node data transfer and ensures that data packets are properly framed for transmission over the physical medium.

Specifically, MAC addressing is crucial at this layer as it assigns a unique identifier to each network interface card (NIC), allowing devices on the same local network to communicate effectively. This addressing scheme is vital in managing how data packets are directed to specific devices rather than to all devices on the network, which is fundamental for efficient data handling and collision detection.

While other functionalities such as routing, session management, or data framing might touch upon Layer 2 support in certain aspects, they primarily operate at different layers of the OSI model, with routing being associated with Layer 3 (Network Layer) and session management tied to Layer 5 (Session Layer). Therefore, MAC or physical addressing is the most accurate and essential representation of Layer 2's primary function.