Which concept describes the data link layer's connection to the network layer above and its control of the physical hardware?

Which concept describes the data link layer's connection to the network layer above and its control of the physical hardware?

• A. Data Link Layer Sublayers
• B. Network Layer Protocol
• C. Transport Layer
• D. Session Layer

Answer: (A)

The Data Link Layer Sublayers. The data link layer sits between the network layer above and the physical layer below and is itself divided into two sublayers: the Logical Link Control (LLC) and the Media Access Control (MAC). The LLC provides the interface and services to the network layer above, such as framing, error detection, and flow control, while the MAC sublayer handles access to the physical medium and the actual control of hardware to transmit data. This combination explains how the data link layer connects to the network layer above and how it governs the hardware that carries the data. The other options describe functions from other layers—routing and network-layer responsibilities, end-to-end transport, and session management—so they don’t capture both aspects together.

The Data Link Layer Sublayers. The data link layer sits between the network layer above and the physical layer below and is itself divided into two sublayers: the Logical Link Control (LLC) and the Media Access Control (MAC). The LLC provides the interface and services to the network layer above, such as framing, error detection, and flow control, while the MAC sublayer handles access to the physical medium and the actual control of hardware to transmit data. This combination explains how the data link layer connects to the network layer above and how it governs the hardware that carries the data. The other options describe functions from other layers—routing and network-layer responsibilities, end-to-end transport, and session management—so they don’t capture both aspects together.