What is OSI Model _ 7 Layers Explained

[Virtual Presenter] The OSI Model is a set of rules that explains how different computer systems communicate over a network. It consists of seven layers, each with specific functions and responsibilities. These layers work together to enable different devices and technologies to communicate effectively. The OSI Model provides a clear structure for data transmission and managing network issues. It is widely used as a reference to understand how network systems function. The seven layers of the OSI Model are: Physical Layer, Data Link Layer, Network Layer, Transport Layer, Session Layer, Presentation Layer, and Application Layer. Each layer plays a crucial role in handling data, and they work together seamlessly to ensure efficient communication between devices..

[Audio] The Physical Layer transmits individual bits from one node to another, converting the received signal into 0s and 1s and sending it to the Data Link Layer, which assembles the frame. Common physical layer devices include Hubs, Repeaters, Modems, and Cables. The Physical Layer synchronizes bits by providing a clock, controlling both sender and receiver, and defines the transmission rate, determining how data flows between connected devices, arranging devices in a network..

[Audio] The Receiver's MAC address is obtained by placing an ARP request onto the wire asking, "Who has that IP address?" and the destination host will reply with its MAC address. The Data Link Layer performs various functions, including framing, physical addressing, error control, flow control, and access control. Framing attaches special bit patterns to the beginning and end of the frame, enabling the sender to transmit a set of bits that are meaningful to the receiver. Physical addressing adds the MAC addresses of the sender and/or receiver in the header of each frame. Error control detects and retransmits damaged or lost frames, ensuring accurate data delivery. Flow control coordinates the amount of data that can be sent before receiving an acknowledgment, preventing corruption caused by varying data rates. Access control determines which device has control over the channel at a given time when multiple devices share a single communication channel..

[Audio] Data flows through the OSI model in a step-by-step process. Each layer plays a crucial role in ensuring the data reaches its destination correctly. The Application Layer receives data from the user, such as Person A sending an email to Person B. The data is then passed on to the Presentation Layer, where it's prepared for transmission. The data is formatted and encrypted to ensure secure and efficient transfer. The Session Layer establishes a connection between the sender and receiver on the internet. The Transport Layer breaks down the data into smaller segments for reliable delivery. The Network Layer packages these segments into packets and routes them to their destination. The Data Link Layer frames these packets and sends them to the next device. Finally, the Physical Layer converts these frames into bits and transmits them physically over the network. Each layer adds specific information to ensure the data reaches its destination correctly, and these steps are reversed upon arrival..

[Audio] At the transport layer, our email data is divided into smaller segments. Each segment receives a distinct sequence number, and error-checking information is incorporated to guarantee the accuracy of the data. This guarantees that if any mistakes arise during transmission, they can be identified and rectified..

[Audio] The OSI Model matters because it provides a clear structure of how data moves in the network. Each layer has its specific role, helping in understanding, identifying, and solving complex network problems easily by focusing on one of the layers rather than the entire network..

[Audio] The OSI Model is a conceptual framework that defines the communication of a computing system into seven different layers. Dividing network communication into these seven layers makes it easier to understand and troubleshoot. Additionally, this framework standardizes network communications, allowing for easier diagnosis of network problems and implementation of improvements through separate updates. However, the OSI Model also has its drawbacks, including complexity and difficulty in understanding for beginners. Furthermore, it is not directly applicable in real-life networking, where the Internet protocol suite (TCP/IP) is more commonly used..

[Audio] Each layer in the OSI Model adds its own set of rules and operations, making the process more time-consuming and less efficient. However, this layered approach also allows for smooth data transmission from the source to the destination, as each layer relies on the services provided by the layer below it and provides services to the layer above it. In addition, the OSI Model helps network administrators isolate problems more easily by breaking down communication into layers..