Foreword Special Issue on Tools for Computer Communication Systems.

Computer communication systems are complex systems in which both computing power and communications capabilities play a key role. Examples of such systems range from worldwide data and voice communications networks to local area networks, and even encompass the more recent multiprocessor computer systems. In the past, the design and development of such systems has been done in a fairly ad hoc manner. However, it is increasingly apparent that in order to understand and develop sucy systems, it is necessary to have a more systematic approach to designing and studying such systems.