There are two important network architectures. They are ISO-OSIreference model and TCP/IP reference model.
THE OSI REFRENCE MODEL: - This reference model is proposed by international standard organization as a first step towards standardization of the protocol s used in various layer in 1983 by day and Zimmermann. This model is called open system. Interconnection (OSI) reference model. It is referred OSI as it deals with connection open systems. That is the systems are open for communication with other systems.
IT CONSIST 7 LAYERS:-
THE PRINCIPAL THAT WERE APPLIED TO ARRIVE AT 7 LAYERS:-