Modern computer scientists need to understand both the theoretical and practical aspects of computer networking. As computer science teaching methods continue to mature, experiences in mixing theory and application have been shared in the community [Marti 96]. While the literature is rich with experiences in applied or project based courses in artificial intelligence, architecture, software engineering, data structures and algorithms, few have addressed the challenge of coordinating theory and practice in computer networking courses.Combining theory and practice in a single course on computer networks is difficult because of the complexity and scale of modern networks. Classroom modeling of networks is a technique to illustrate the theoretical aspects of networking through practical models of computer networks. At West Point we are evolving our network course to use network modeling and simple simulation as a visualization tool to show how networks operate and the performance tradeoffs associated with network design decisions. This approach provides the opportunity to do more than teach an undergraduate survey course in computer networking.