Communicating Systems with UML 2: Modeling and Analysis of Network Protocols

Chapter 1

Why Use UML to Model Network Protocols?

1.1. Modeling network protocols

1.1.1. The complexity of communication protocols

In the future, as advanced architectures such as multimedia systems, control systems, distributed embedded systems, etc, become increasingly complex, they will still need to fulfill a set of well-defined requirements regarding their global quality. Meeting these requirements needs a deep understanding of the full distributed system, i.e. of all its local entities and all the communications between those local entities, in order to be able to represent and anticipate their resulting global behavior.

As a consequence, a system’s (global) behavior will depend on:

– local activities and their local data; and also on

– the messages that are sent, received and processed by the various interconnected entities.

A communication system with all its communication capabilities and configurations is often the basic and most difficult sub-system to correctly understand and build. The reason why this particular problem can be very complex, and lead to many design problems and implementation bugs, needs to be emphasized. To understand it, consider N processors that are connected: they can communicate, at a given instant, 2 by 2, 3 by 3, etc, or use full communication between them all, in which the N processors interact. The sum of the resulting combinations, which may need to be fully analyzed in order to understand the globally interconnected behavior, is then of ...