OSI

Each letter in the term is pronounced separately, and the term in the networking is an acronym for two things. One of which is Open source Initiative, however, this article does not deal with this term in this context. The second meaning of the term OSI is Open System Interconnection and this article is all about open system interconnection. OSI is an ISO standard that is implemented worldwide, which defines a networking framework for the implementation of the protocol in the seven layers. The work on OSI was done by the International organization of standardization and the final and refined standard for the OSI was published and announced o the world in the year 1984. Since then the same OSI model is being used till date in every network, throughout the world.

In the OSI model the control is passed from one layer to the next and then back to the first layer thorough proper channel. The control or the procedure in the model or in the seven layers always starts from the application layer before going down the model to the first layer and then going back up to the top one. These layers are nothing but a group of protocols or devices or equipment that performs similar communication functions. There are a total of 7 layers in the OSI model. These are mentioned in the following material.

The first layer is the physical layer that deals with the electrical and physical specifications of the devices, and then there is layer 2 which is the data link layer, which contains the different devices to transfer the data. The layer 3 is the network layer, the layer 4 is the transport layer, the layer 5 is Session layer, the layer 6 is presentation layer and the last layer, layer 7 is the application layer.