The OSI Model with complete Explanation

Diagram

Definition:  The OSI model defines internetworking in terms of a vertical stack of seven layers, a layer framework for the design of network system that allows communication across all type of computer system regardless of their underline the architecture.

v  The OSI (Open System Interconnection) model was created in 1984 by ISO (International standard organization) to help standardize communication b/w computer system. It divides communications into seven different layers, which each include multiple hardware standards, Protocol, or other types of servers.

v  The Upper three layers are user Supporting Layers.

v  The lower three layers are network supporting layers.

The OSI model consists of seven layers;

7) Application layer

This application layer is responsible for providing different services to the application. Example of services provided by this layer is file transfer, electronic messaging e-mail virtual terminal access and network management.

6) Presentation layer

This layer is responsible for converting the data into Binary form (0,1).This layer makes the communication between two host possible.

5) Session layer

This layer is responsible for date sending and receiving. This layer is responsible for establishing the process-to-process communication between the hosts in the network. It monitors the data. It create a session.

4) Transport layer

This layer is responsible for end-to-end delivers of messages b/w the network host. It also guarantees error free data delivery without loss or duplications.

3) Network layer

The third layer of OSI model is responsible for routing information from one network device to another.

 This layer is responsible for delivery of individual packet from host to the destination.

2) Data link layer

The 2^nd  layer of OSI model. Data link layer is responsible for moving frames from one source to next destination.

1) Physical layer

Physical layer is responsible for movement for individual bit from source to destination. Physical layer is responsible for translating row bit stream over the physical cable. The physical layer defines the hardware items such as cables , cards, voltages etc.