Simulating trunk and signaling networks allows planners to examine network survivability, capacity, and the impact of new service introductions. The challenge is to accurately predict network performance and behavior for a rapidly changing environment, and for the very large networks that are encountered in the public telephone system. This paper describes the discrete event modeling of SS7 signaling networks that enable dynamic network analysis for very large, highly realistic, network models. The primary distinction between the authors approach and related work is the development of a very detailed model, one that incorporates most SS7 message-handling and network-management procedures. Their approach is aimed at accurately reproducing dynamic network behavior at a level similar to the models described by Hutchinson and Patten (1986), and Unger and Bidulock (1982) . They define network simulation objectives and the SS7 model components and functions, and then give a brief overview of how a specific network model is created, including a description of the model's implementation and how it was validated. They also discuss a model and simulation experiments for a large part of the Ameritech network. >