The OSI is a reference model that serves as a framework for the development of communications protocols. The model is intended to provide guidance for the establishment of common standards to facilitate communications between different vendors' products.

Structure based on a 7 layer model developed by ISO which provides a framework for building protocols that allow different computer manufacturers' machines to communicate with one another. The layers are: Application - user Programs Presentation - data interpretation Session - control of sessions between hosts Transport - transmission control Network - flow control, routing Data Link - maintain and release data Physical - physical media definition

A set of protocols specified by ISO for interconnectiong networks. See ISO/OSI