What is the main purpose of OSI model
- OSI (Open Systems Interconnection) model
- TCP/IP model
Networking technologies can be classified based on the OSI model layer (or layers) at which they operate. At a certain layer of the OSI reference model, knowing how that technology performs a particular function helps you determine whether or not the device will be able to communicate with another device using a similar technology at that layer. Data flows in a network from one device to another in accordance with the OSI model, which is a conceptual model. In 1984, the International Organization for Standardization (ISO) created the OSI model, and it was updated in 1994 to coordinate the development of standards for interconnected information-processing systems. The model describes seven layers, beginning with the physical connection and ending with the application. As show in the figure below, there are seven layers in OSI model.
Those are Physical Layer, Datalink Layer, Network Layer, Transport Layer, Session Layer, Presentation Layer and Application Layer. The top three layers (Application, Presentation, and Session) are known as the upper layers. Normally, the four bottom layers (Transport, Network, Datalink, Physical) are referred to as the lower layers. For remembering the order of the layers, there are two common mnemonics:
Layer 7 to 1: All People Seem To Need Data Processing.