Data Link Layer

The Data Link layer defines how devices communicate over a network. It is responsible for managing physical addressing and switching on a network. Physical (MAC) addresses are handled here. Information traversing this layer is known as a "frame".

It's responsible for node-to-node data transfer. It handles the physical addressing and error correction and control. It ensures data transfer is error-free from one node to another, over the Physical Layer.

The major role is to ensure error-free transmission of information. It's also responsible for encoding, decode and organizing the outgoing and incoming data.

Info

This is considered the most complicated layer of the OSI model as it hides all the underlying complexities of the hardware from the other above layers.