The challenge in the metropolitan area networks (MAN) is to provide fast, flexible, and cost-effective service. Simplified protocol stack and dynamic bandwidth provisioning become the major approaches to face such challenge. To achieve the design goals, this book introduces an innovative multi-token controlled WDM ring solution (termed LightRing) with integrated dynamic lightpath switching and optical packet switching. To achieve dynamic lightpath provisioning on demand, the LightRing solution applies a distributed and contention-free multi-token reservation mechanism for lightpath setup and teardown. To achieve high efficiency and low node cost for packet switching, the LightRing applies a dynamic control on the token holding time based on a target token inter-arrival time. These two alternative switching techniques are dynamically selected by a novel multi-token control protocol that regulates the transmissions of the nodes on the ring. The proposed architecture and protocol are good candidates for designing IP over WDM networks for MAN, achieving all optical transmission by means of extant optical technologies.