Which layer of the OSI model is responsible for data link layer functions?

The data link layer is the second layer of the OSI (Open Systems Interconnection) model, and it plays a crucial role in facilitating reliable communication between directly connected nodes. Its primary functions include framing, physical addressing, and error detection and correction. The data link layer is responsible for ensuring that data packets are delivered to the correct destination on the local network segment and manages how data is placed and received from the physical medium.

This layer provides a means to detect errors and control access to the physical transmission medium, which enables devices on the same local area network (LAN) to communicate effectively. It also defines how devices on the same network segment handle framing and the addressing schemes necessary for proper communication.

In contrast, the transport layer is responsible for end-to-end communication and reliability across networks, while the network layer deals with routing and forwarding of packets across multiple networks. The physical layer focuses on the actual transmission of raw bitstream over a physical medium. Each of these layers has distinct responsibilities, which is why the data link layer is specifically identified for functions associated with local link communications.