Open System Interconnection (OSI): A Seven Layered Model

Abstract

Open System Interconnection model is a seven layer architecture model which describes how data communication process takes place from one computer to another computer through network. This model divides the communication process into seven steps called layers. The basic purpose of this model is to show how to communication is possible between different systems without requiring any changes to the logic of underlying hardware and software. Basically this model is the way of subdividing the communication system into smaller parts called layers. These layers are Physical layer, Data link layer, Network layer, Transport layer, Session layer, Presentation layer and Application layer. Each layer of this model performs well defined function and provides services to upper layer and depend upon the services provide by layer below it. The main purpose of this paper is to explain about Open System Interconnection Model and all layers of this model.