What is the responsibility of the data link layer (Layer 2)?
The data link layer defines how data is formatted from transmission and how access to the physical media is controlled. This layer also typically includes error correction to ensure reliable delivery of data.The data link layer translates messages from the network layer into bits for the physical layer, and it enables the network layer to control the interconnection of data circuits within the physical layer. Its specifications define different network and protocol characteristics, including physical addressing, error notification, network topology, and sequencing of frames.Data-link protocols provide the delivery across individual links and are concerned with the different media types, such as 802.2 and 802.3. The data link layer is responsible for putting 1s and 0s into a logical group. These 1s and 0s are then put on the physical wire. Some examples of data link layer implementations are IEEE 802.2/802.3, IEEE 802.5/802.2, packet trailer (for Ethernet, frame check sequence [FCS], or cyclic redundancy check [CRC]), Fiber Distributed Data Interface (FDDI), High-Level Data Link Control (HDLC), and Frame Relay.