OSI - Data Link Layer

-

Overview

In the previous blog, we discussed about the physical layer and it's importance at transmitting the data in the form of bits and bytes. Now, we will be addressing Data link layer and how it prepares packets for transport over different types of media and physical network components.

Data Link Layer

                       The data link layer is the 2nd layer in the OSI model. It's function is to primarily prepare packets for transmission over the physical media. It also serves to control the flow of data that will traverse the physical media. The Data link layer PDU (Protocol Data Unit) is the Frames. The two main functions performed at this layer include framing of packets received from the network layer and control of how data is handled by the physical media through MAC (Media Access Control) and detection of errors. Data Link Layer also includes these functions:

Frame Synchronization: 

                      The Data Link layer synchronizes the transmission of data frames between devices. It ensures that both the sender and receiver are operating at the same speed and are ready to receive data. 

Error Detection and Correction: 

                       The Data Link layer detects and corrects errors that may occur during data transmission. This is usually achieved using techniques such as cyclic redundancy check.

Flow Control:

                       The Data link layer controls access to the physical medium, ensuring that only one device can transmit data at a time. This helps prevent collisions and ensures that data is transmitted efficiently. 

Access Control:

                        The Data link layer manages the flow of data between devices to prevent data loss or buffer overflow. It ensures that data is transmitted at a rate that the receiving device can handle. 

Addressing:

                     The Data link layer assigns unique addresses to devices on the network, allowing them to identified and reached by other devices. 

Protocols at the Data Link layer

Ethernet: 

Ethernet is the most widely used protocol in this layer. It defines the format of Ethernet frames, the access method (CSMA/CD), and the physical addressing (MAC addresses). Ethernet provides reliable and efficient Local Area Network (LAN) communication. 

Point - to - point Protocol:

PPP is a protocol commonly used in dial-up connections and point-to-point links. It establishes a direct connection between two nodes and supports multiple network layer protocols, such as IP, over a single link.

Wi-Fi (IEEE 802.11):

The Wi-fi protocols enables wireless communication within local area network. It defines the format of Wi-Fi frames and the mechanisms for access control and data transmission over wireless media. 

Hoping that the Functions of Data link layer are clear to you. Like, Share and Comment your view on DDL :)
 Happy Networking!



Comments

Post a Comment

Popular posts from this blog

The D̶i̶g̶i̶t̶a̶l̶ Computer Evolution

-
Image
 Introduction                                  The invention of the Computer has been one of the most significant technological advancements of the past century. From the early days of mainframe systems to modern laptops and smartphones, computers have become an integral part of our daily lives. In this blog post, we will explore the positive impact of computers on humans, their pros and cons, the benefits of computer technology for humans, and the latest updates in computer technology that have shaped our lives.  Benefits of Computers for Humans:                       Computers changed the whole system of our workstyle, communication methods, and interaction ways with the world. They have made our lives easier and more efficient in numerous ways.  Digitalized Professional Lives                 ...
Read more

Physical layer in OSI Model

-
Image
                                    The Open System Interconnection comprises seven OSI Layers with their individual functions. In this blog series on Learn Networking, I am going to tell you about the first and foremost layer of OSI Model i.e., Physical Layer...                                                        The Physical Layer in the OSI Model defines electrical and physical specifications for connections between devices. The physical layer establishes how a device, like a computer, interacts with a transmission medium, be it copper or optical cable. It also defines the encoding techniques, determining the representation of 0s and 1s within a signal. It encompasses pin configuration, voltage levels, cable standards, as well as components like hubs...
Read more

What is TCP/IP?

-
Image
Introduction                        This is the second blog in the networking fundamentals series in which we try to specify the what-abouts of TCP/IP Protocol suite. I believe this will be the most commonly used protocol on the internet. While it may not directly be used for communication, it is encapsulated under other protocols like HTTP(s), FTP and SFTP, etc., We will try to cover the typical use of TCP/IP and compare the same with OSI Model.                         Let's get started with details about TCP/IP. TCP is known as Transmission Control Protocol, which is connection-oriented protocol unlike our friend UDP. This protocol relies on sequential data transfer and guarantees the delivery. While these may seem an essential thing, this adds a certain amount of complexity to the implementation as well... Transmission Protocol           ...
Read more