What is the OSI (Open Systems Interconnection) Reference Model?
What is an OSI Reference Model?
The OSI (Open Systems Interconnection) Reference Model is a layered framework used to explain and standardize how data is exchanged between two computers or networks across a network media. It is intended to be a guide to help ensure data will be reliably delivered in the same format across different systems.
The OSI model is made up of seven layers, with each layer performing specific communication functions. These seven layers are divided into two categories: upper layers (4-7), which provide applications with services, and lower layers (1-3), which provide the necessary hardware and software support. Each layer offers different types of services and interacts with its corresponding counterpart on the other side of the connection.
The Seven Layers of the OSI Model
The following are the seven layers of the OSI model, from the highest layer to the lowest:
- Application Layer
- Presentation Layer
- Session Layer
- Transport Layer
- Network Layer
- Data Link Layer
- Physical Layer
Each layer offers different kinds of services and interacts with its corresponding counterpart on the other side of the connection. For example, at the application layer the client computer can send an email message, while at the transport layer the server computer ensures the message is sent reliably. At the network layer the client computer might request a web page, and the server computer sends back the requested web page.
- Application Layer: It is Responsibble for Communicating wirth user Application
- Presentation Layer: It is Responsible for Encrypting and Decrypting user level Data
- Session Layer: It is Responsible for Establisged session for Communication
- Transport Layer: It is Responsible for Deside Nature of conectivity, connection less or connection oriented
- Network Layer: It is responsible for Trafic Control in a Network
- Data Link Layer: It is Responsible for Error detection or Error Correction
- Physical Layer: It is Responsible for converting the Data into bits and bytes formate and Transfer Through Physical media
The Benefits of the OSI Model
The primary benefit of the OSI model is that it provides a standardized framework for communication between computer systems. This simplifies the process of exchanging data because both computers know exactly what to do at each layer. Additionally, if there is a problem with one of the layers, it can be easily identified and rectified. The OSI Reference Model also makes it possible for new technologies to develop, since the layers can be used to add new features without needing to redesign the entire protocol.
The OSI Reference Model is an important tool for enabling effective communication between computers and networks. It is a commonly used standard and is an integral part of today's computer networks. While the OSI model has been around for over three decades, it continues to remain relevant due to its flexibility and robust design.