Layered connection management for dynamic all-optical networks

Traditionally, optical channels are manually provisioned and exist for months or years. New automated means of managing network resources, together with demands for greater flexibility from the customers, have led to the concept of dynamic optical connections. However, over time, the establishment and removal of these connections in the presence of changing traffic demands can lead to inefficient exploitation of the underlying resources. The authors propose a novel dual-layered connection management system. Distributed, fast and simplified control plane functionalities are used at the lower layer to provide efficient real-time per-connection resource management. The time-consuming optimisation functions are located in a centralised upper layer where they are able to achieve more efficient solutions that can improve the overall network utilisation. The control of the lower layer by the upper level is carried out via two means, namely: influence-based path calculation for short-lived connections and intrusive redeployment for long-lived connections. Simulation results, under a variety of conditions, show an improvement in performance of over 10% in each of the metrics considered for both long-lived and short-lived connections for two commonly cited test networks. We therefore conclude that the proposed system can offer worthwhile improvements in network performance.