laag2

Laag2 refers to the Data Link Layer of the OSI model. This layer is responsible for the reliable transfer of data between nodes on a network. It takes the raw bits from the Physical Layer and organizes them into frames. Key functions of the Data Link Layer include error detection and correction, physical addressing (MAC addresses), and flow control.

The Data Link Layer is divided into two sublayers: the Media Access Control (MAC) sublayer and the Logical Link Control (LLC) sublayer. The MAC sublayer handles the protocol for how devices access the physical medium, preventing collisions in shared network environments. Examples include CSMA/CD for Ethernet and CSMA/CA for Wi-Fi. The LLC sublayer provides a standardized interface to the Network Layer, regardless of the specific MAC protocol being used.

Common protocols operating at the Data Link Layer include Ethernet, Wi-Fi (IEEE 802.11), PPP (Point-to-Point Protocol), and Frame Relay. These protocols define the frame formats, addressing schemes, and mechanisms for data transmission over a local network segment or a point-to-point link. Understanding the Data Link Layer is crucial for network troubleshooting and designing efficient network infrastructures.