What do you mean by OSI?
The Open System Interconnection (OSI) reference model explains how information from a software application in one computer moves by a network medium to a software application in another computer. The OSI reference model is a conceptual model composed of seven layers, every specifying particular network functions. The model was developed by the International Standardization Organization (ISO) in 1984, and it is now considered the primary architectural model for inter-computer communications.