19 Apr Data Link Layer in OSI Model
The second layer in the OSI Model is Data Link Layer that transforms the physical layer to a reliable link and error free to the network layer.
The following are the roles of data link layer in OSI Model,
The stream of bits are divided into data units called frames.
A header is added to the frame for defining the physical address of the sender or receiver of the frame. This is done only if the frames are to be distributed to different systems in the same network.
To prevent duplication of frames, the Data Link Layer use Error Control mechanism. This is required to detect and retransmit frames that gets damaged or lost in transit. Error Control adds a trailer to the end of the frame.
To prevent chaotic traffic at the receiver dise, the data link layer has a mechanism known as Flow Control. This is required only if the data receiving rate of receiver is less than the rate at which the data is produced.