Distributed network control for wavelength routed optical networks

Abstract

This paper describes an architecture for adding an underlying wavelength-routed optical layer to a standard ATM network. The optical layer provides reconfigurable lightpaths that serve as links between electronic ATM switches. A lightpath is carried on a particular wavelength and path in the underlying optical wavelength-routed network. This work focuses on the mechanisms for controlling the optical layer. Distributed control protocols are provided for setting up and taking down lightpaths reliably and for updating the topology of the network, including the lightpaths. These protocols allow lightpath originators to obtain resources with high probability by minimizing reservation conflicts, allow lightpaths to stay up even if controllers along the path in the network fail, ensure that controllers in the network have a consistent view of the state of each lightpath, and ensure that all resources taken up by a lightpath are released once the lightpath is taken down.