What is Grooming Routing and Wavelength Assignment (GRWA)

The data transport structure of the modern networks is moving toward a model of high-speed packet/frame/timeslot capable routers/switches/cross-connects interconnected by automatically configured lambda switch capable optical core networks. One of the main challenges today is the engineering of scalable and resilient automated control planes to encompass these diverse technologies in order to dynamically perform the task of bandwidth provisioning, under quality of service (QoS) constraints, for large and multi-layered networks. In this context, a considerable number of parameters concerning resource state (i.e., not only link state) must be frequently updated across the network for distributed decision taking concerning traffic routing; and flooding may no longer be the best strategy for disseminating this information in order to synchronize these distributed databases used in scalable approaches. This chapter presents a proposal for an overlay service-oriented information plane based on distributed hash tables (DHT) for resource discovery and sharing using content-addressable networks (CAN). It also investigates deterministic reconfigurations over CAN topology for taking advantage of the small-world effect in order to reduce the number of hops needed per control plane functionalities. Analytical results indicate significant reduction in routing traffic information over the physical layer of large networks but the latency for information retrieval and updating should be a concern for future investigations.