OSI Reference Model

Introduction

The Open Systems Interconnection (OSI) Reference Model, developed by the International Organization for Standardization (ISO) in 1984, is a conceptual framework that standardizes the functions of a communication system into seven distinct layers. It provides a universal blueprint for understanding, designing, and troubleshooting network architectures. Each layer performs specific tasks and interacts with the layers above and below it, ensuring seamless end-to-end communication.

This lecture note outlines the seven layers of the OSI model, their functions, key responsibilities, and examples of protocols, devices, or technologies associated with each layer. It also covers the concept of data encapsulation and the model’s practical applications.