Briefly explain the functions of the data link layer

Question

What will be an ideal response?

Answer 1

One of the key functions of the data link layer is to frame binary bits received from the physical layer. A frame then is the structure given to binary bits at the data link layer. A frame may have to pass through many intermediary devices and networks on its path from the originating source to the final destination device. Think of it as a relay in which one runner passes the baton, in this case a frame, to the next runner, in this case the next device. While moving the frames between each sending and receiving device in the relay, the data link layer ensures that one device does not overwhelm the other with too much data at one time. Flow control is used so that the sending device does not overwhelm the receiving device in a communication. Imagine a single clerk in a store with 20 customers to serve. Without flow control, in this case a single-file line that the customers must wait in, the clerk could be overwhelmed with customer demands. Flow control is important for many human as well as data communications applications.