What is the Open Systems Interconnection model? What is its relation to a communication Model? Mention the different layers in an OSI model? What is the relation between these layers? Which are the host layers and what do they do? How are they different from the Media Layers? Differentiate between Protocol Data Unit and Service data unit.
Open Systems Interconnection or OSI is a reference model for how programs can communicate over a network. A reference model is an abstract framework for comprehending relationships. The objective of the Open Systems Interconnection reference model is to lead developers and vendors so that the digital communication products and applications they build will interoperate as well as to help clear differences between communications tools.
OSI was developed by representatives of major telecommunications and computer companies that started in 1983. It was originally designed to be a complete specification of real interfaces. The committee decided to start a common reference model as an alternative, where others could build up detailed interfaces.
