Data Link (Data Link) layer, we can address the following important reasons to answer the question of why it is required in computer networks:
Physical Environment Management: The Data Link layer determines how data is transmitted and edited and controlled over the physical environment. Different communication environments (, for example, wireless, wired, optical fiber ) have different requirements, and this layer addresses these differences and provides data transmission.
Creating Data Frames: The Data Link layer converts data from high layers into frames. Frames are packages that determine how data should be transmitted in the physical environment. These frameworks include address information, error control information, and other management information.
Addressing: The Data Link layer allows each device to receive a unique address ( usually MAC address ) and communicate via these addresses. This helps identify and communicate devices.
Error Control: This layer performs error check to ensure that the transmitted data is received accurately and reliably. Errors can occur during data transmission, so error detection and correction protect data integrity.
Flow Control: Regulates network traffic and controls data transmission. This helps balance data flow between slow and fast devices and improves network performance.
Embellishment (Collision Handling): In some networks, conflicts (collision) may occur, especially in shared networks such as Ethernet. The Data Link layer detects these conflicts and manages how to handle them.
Security: The Data Link layer plays an important role for network security. It ensures that data is protected against unauthorized access and may include mechanisms such as authentication and encryption to increase security.
As a result, the Data Link layer enables computer networks to operate in a healthy and reliable manner by regulating data transmission, maintaining data integrity, managing addressing, and improving the performance of the network. Without this layer, data transmission and communication become complicated and the reliability of the network decreases.