The optical control plane and a novel unified control plane architecture for IP/WDM networks

An effective optical control plane is crucial in the design and deployment of a transport network as it provides the means for intelligently provisioning, restoring, and managing network resources, leading in turn to their more efficient use. This chapter provides an overview of current protocols utilized for the control plane in optical networks and then delves into a new unified control plane architecture for IP-over-WDM networks that manages both routers and optical switches. Provisioning, routing, and signaling protocols for this control model are also presented, together with its benefits, including the support of interdomain routing/signaling and the support of restoration at any granularity. Introduction In the last two decades optical communications have evolved from not only providing transmission capacities to higher transport levels, such as inter-router connectivity in an IP-centric infrastructure, to providing the intelligence required for efficient point-and-click provisioning services, as well as resilience against potential fiber or node failures. This is possible due to the emergence of optical network elements that carry the intelligence required to efficiently manage such networks. Current deployments of wavelength division multiplexed (WDM)-based optical transport networks have met the challenge of accommodating the phenomenal growth of IP data traffic while providing novel services such as rapid provisioning and restoration of very high bandwidth circuits, and bandwidth on demand.