Distributed network control for optical networks

This paper describes an architecture for controlling a wavelength-routed optical network. The optical network provides reconfigurable connections that can be used to carry different types of data, at possibly different bit rates. A connection consists of a path in the network and a wavelength on each link in that path. This work focuses on the mechanisms for controlling the optical connections. Distributed control protocols are provided for setting up and taking down connections reliably. These protocols allow connection originators to obtain resources with high probability by minimizing reservation conflicts, allow connections 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 connection, and ensure that all resources taken up by a connection are released once the connection is taken down. Fast protocols are also proposed for handling link failures and wavelength failures on a link. These protocols are general in that they can be used in networks with: 1) different kinds of node architectures (electrical/optical switching, with or without wavelength conversion, etc.), 2) different route-computation algorithms that reflect the underlying constraints imposed by the nodes and the physical layer, and 3) any kind of underlying mechanism using which the network controllers can communicate with each other.