What is OSI Model | Open System Interconnection | 7 layers | Explained

The OSI (Open Systems Interconnection) model is a conceptual framework that standardizes and describes the functions and interactions of network protocols and systems. It provides a structured approach to understanding how different network protocols and technologies work together to enable communication between devices in a network. The OSI model consists of seven layers, each responsible for specific functions. Let's explore each layer:

Physical Layer:

This layer deals with the physical transmission of data bits over the network medium.

It defines characteristics such as electrical voltages, cable specifications, data rates, and physical connectors.

Data Link Layer:

The data link layer is responsible for the reliable transfer of data frames between directly connected devices.

It provides error detection and correction, flow control, and media access control (MAC) addressing.

Network Layer:

The network layer focuses on logical addressing and routing of data across multiple networks.

It determines the best path for data transmission, performs routing functions, and handles network congestion.

Transport Layer:

The transport layer ensures reliable and efficient data transfer between end-to-end processes on different devices.

It establishes connections, manages data segmentation, implements flow control, and handles error recovery.

Session Layer:

The session layer manages and synchronizes communication sessions between devices.

It establishes, maintains, and terminates connections, and handles session checkpointing and recovery.

Presentation Layer:

The presentation layer is responsible for data representation, ensuring compatibility between different systems.

It deals with data encryption, compression, character encoding, and protocol conversion.

Application Layer:

The application layer provides network services directly to users and applications.

It encompasses protocols and services for specific applications such as email, file transfer, web browsing, and remote access.

The OSI model provides a layered approach to network communication, where each layer interacts with the layers above and below it. The model allows for interoperability between different network devices and facilitates the development and implementation of network protocols and technologies.

It's important to note that the OSI model is a conceptual framework and does not correspond directly to the architecture of all networking systems. However, it serves as a reference model for understanding and discussing network protocols and their interactions.