Fundamentals of the layer service definitions and protocol specifications

The paper discusses the modeling techniques used in open Systems Interconnection standardization. There is a need for sudivision of the standardization work in order to allow orderly management of development, and the means of achieving this modularity by use of the concepts of service and protocol is explained. The conventions used in defining services are set out, so as to form an introduction to the detailed description in later papers. Various extension to the basic concepts of service and protocol are presented, and the relation of the models established to the real world are discussed.