Which OSI layer includes Logical Link Control (LLC) and Media Access Control (MAC)?

• A. Layer 1
• B. Layer 2
• C. Layer 3
• D. Layer 5

Answer: (B)

The correct answer is Layer 2, which is known as the Data Link layer. This layer is responsible for node-to-node data transfer and error correction from the physical layer, ensuring that data frames are transmitted effectively between devices on the same local area network.

Within Layer 2, there are two important sublayers: the Logical Link Control (LLC) and the Media Access Control (MAC). The LLC sublayer manages the communication between the network layer and the data link layer, providing a way to identify the protocol used on the network. Meanwhile, the MAC sublayer controls how devices on the local network share and access the medium for data transfer, determining how frames are placed on the network and managing access to the channel.

Thus, Layer 2 encapsulates both the LLC and MAC functionalities, making it the pivotal layer for data transfer and logical addressing in networking.