Which of the following is NOT a function of the data link layer?

The data link layer of the OSI model is primarily responsible for the node-to-node transfer of data and includes functions such as framing, addressing, and error detection.

Framing involves encapsulating network layer packets into frames, which makes it easier to manage the data as it passes through the transmission medium. Addressing at the data link layer refers to the inclusion of hardware addresses (like MAC addresses) to ensure that frames are delivered to the correct device on a network. Error detection is crucial as it helps identify whether data has been corrupted during transmission, enabling the receiving device to request retransmission if necessary.

Routing, however, is not a function of the data link layer. Routing is managed at the network layer, which is responsible for determining the best path for data to travel between devices across different networks. The role of routing includes making decisions based on network conditions and addressing, which falls outside the purview of the data link layer’s specific responsibilities. Therefore, it is accurate to identify routing as the function that does not belong to the data link layer.