Protocol engineering for application layer protocols

A protocol engineering approach based on specifications in the broadband specification language, called π-language, is presented. This language aids in the design process of open systems interconnection (OSI) applications. The application layer structure is surveyed. The concepts of standards in that layer are presented with respect to the formal description of application protocols. The authors explain the differences between services and protocols in the application layer and those of lower layers and consider how they can be formally described with the language. The advantages and drawbacks of formal specifications written in the language are discussed