The two sublayers of the OSI model data link layer are the Media Access Control (MAC) layer and the Logical Link Control (LLC) layer.
Here's a breakdown of each sublayer:
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Media Access Control (MAC) Layer: This sublayer is responsible for controlling how devices in a network gain access to a medium (e.g., a cable or wireless channel) and transmit data. It handles addressing and channel access control mechanisms. MAC addresses, which are unique hardware identifiers, are used at this level. The MAC sublayer essentially governs who gets to talk and when on a shared medium.
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Logical Link Control (LLC) Layer: This sublayer provides an interface between the network layer (layer 3) and the MAC layer. Its primary function is to provide a reliable data link connection. It handles functions such as error control, flow control, and multiplexing. The LLC layer ensures that data packets are delivered correctly and in the proper order. It acts as a translator between the network layer and the hardware-specific MAC layer.
In essence, the Data Link Layer is divided into these two sublayers to manage both the logical link and physical access aspects of data transmission. The LLC provides network-layer protocol multiplexing, flow control, and error detection/correction while the MAC handles medium access control and addressing.
