Two optical packet switching metropolitan area networks are introduced. They adopt different ring architectures and related media access control protocols. Their simulation system is set up to study both their physical and logical characteristics. Simulation system adopts self-similar traffic that has been demonstrated to accord to real traffic. This simulation system can layout the MAN with optimized network architecture, node scale, wavelength multiplexing number and system physical and logical response parameters according to the design requirements including bandwidth, QOS, traffic load and so on.