OSI model

            The Open Systems Interconnection model (OSI) is a conceptual model that characterizes and standardizes the internal functions of a communication system by partitioning it into abstraction layers. The model is a product of the Open Systems Interconnection project at the International Organization for Standardization (ISO), maintained by the identification ISO/IEC 7498-1.

    The model groups communication functions into seven logical layers.

Ø Layer1: physical layer

Ø Layer2: data link layer

Ø Layer3: network layer

Ø Layer4: transport layer

Ø Layer5: session layer

Ø Layer6: presentation layer

Ø Layer7: application layer