Communicating Structures is a system abstraction that helps to model large-scale distributed systems, whose performance mostly depends on how well the data and messages traffic is organized. The whole variety of "traffic sensitive" communicating systems can be modeled using just a small number of basic primitives which are common for all such systems. The system components are represented simply as nodes. Each node has memory that may contain items. Nets are sets of links that connect the nodes. The items are generated at some nodes and move from node to node along links, with some delay. The item traffic models the message and data traffic in systems. Using uniform, systematic composition of the basic primitives, Communicating Structures are able to approximate the properties and behavior of a broad spectrum of large-scale communicating systems. Communicating Structures Library (CSL) is a core environment for the simulation of large communicating systems. CSL has been used to analyze the architecture of multiprocessor systems, global enterprise intranets, distributed mission-critical applications, and the World-Wide Web.
