Formalized Data Flow Diagrams (FDFD\u27s) provide simple and natural abstractions for specifying network behavior. We have augmented FDFD\u27s by providing (i) a notion of asynchronous timing of events, (ii) a convenient mechanism for describing node classes , and (iii) features for specifying network architecture. These extensions will facilitate the modeling of a large computer network (using the langauge NET-SPECS) and the direct generation of a simulator of that network
