Datalinkkikerros

Datalinkkikerros, also known as the Data Link Layer, is the second layer in the OSI (Open Systems Interconnection) model of computer networking. Its primary function is to establish, maintain, and terminate a reliable link between two directly connected nodes on a network. The layer is responsible for the framing, addressing, and error detection of data packets as they are transmitted over physical links.

The main responsibilities of the datalinkkikerros include dividing network layer packets into frames, adding header and trailer information for proper delivery, and handling error detection using techniques such as CRC (Cyclic Redundancy Check). In addition, it manages flow control to prevent overwhelming the receiving device and may perform error correction if necessary.

Datalinkkikerros operates between the physical layer (layer 1) and the network layer (layer 3). It ensures that the data transfer over the physical medium is error-free and in the correct order. Different types of network environments utilize various protocols at this layer, such as Ethernet, Wi-Fi (IEEE 802.11), and PPP (Point-to-Point Protocol).

In local area networks (LANs), the datalinkkikerros handles media access control (MAC), determining when devices can transmit data to avoid collisions, particularly in shared medium environments. The MAC addresses assigned at this layer uniquely identify devices within a network, facilitating proper data routing.

Overall, the datalinkkikerros is vital for reliable data transfer between directly connected devices, forming a foundational component of network communication systems.