Among the various methods for the modeling of distributed systems that currently are available, the process algebra CCS and Petri nets with extensions are of particular interest. CCS contains the useful concept of synchronized communication. While the theory of CCS is based on a single concept of behavioral equivalence, a variety of such concepts could be incorporated into net theory. Particularly, a clear distinction can be made between the interleaving of concurrent actions and true concurrency. Net theory also provides a suitable basis for the investigation of structural proprties (eg. liveness). Furthermore, various reduction techniques applicable to nets compare favorably with the algebraic analysis methods of CCS. In view of these arguments, a CCS-oriented extension of the Petri net concept, called Communication System Nets, CS-nets, is introduced which incorporates a conditional action feature. Various behavior-preserving reduction techniques are demonstrated along with the applicability of CS-Nets to the specification and verification of distributed systems.