Data Link Layer in Computer networks
According to the OSI (Open System Interconnection) network architectural paradigm, the data link layer is the second layer from the bottom. It is in charge of delivering data from one node to another inside the same local network. Its primary responsibility is to provide error-free information transfer.
Additionally, DLL is in charge of managing the incoming and outgoing data as well as encrypting and decoding it. Because it isolates all of the hardware's underlying details from the other levels above, this layer is regarded as the most sophisticated in the OSI model.
Key Function of Data Link Layer
Framing:
To address and detect errors, the Data Link layer adds headers and trailers to frames containing raw data from the network layer.
Control of Errors:
It uses methods like checksums and cyclic redundancy checks (CRCs) to identify and perhaps fix transmission issues.
Flow Control:
To keep a rapid sender from overloading a slower receiver, the Data Link layer regulates the data transmission rate.
Addressing:
Switches are able to forward frames to the appropriate location by using MAC addresses to identify devices on a local network.
Synchronization:
It guarantees that the incoming data stream can be synchronized with the receiving device.
Limitations of Data Link Layer in Computer Networks
No Routing Capability:
The Data Link Layer can only ensure delivery within the same network segment; it cannot handle end-to-end communication across multiple networks.
Error Handling Dependency:
Although it can detect and correct some errors, it depends on upper layers for handling more complex issues.
Increased Overhead:
Adding headers, trailers, and redundant data (for error correction) increases the size of transmitted data.
Resource Usage:
Flow control and error correction mechanisms may consume additional processing power and memory.
Application of Data Link Layer in Computer networks
Local Area Networks (LANs):
Using protocols like Ethernet (IEEE 802.3), LANs allow dependable communication between devices within a local network.
Switches with MAC Addressing:
Makes it easier for switches to function by forwarding data packets to the appropriate network device using MAC addresses.
Point-to-Point Connections:
Used to create and control direct connections between two nodes in protocols such as PPP (Point-to-Point Protocol).
Wireless Networks (Wi-Fi):
Handles media access and error control by regulating device-to-device communication through protocols such as IEEE 802.11.
