How a Network Can "Think Globally and Act Locally" and Avoid the Hazards of Incoherence in Distributed State Information

We are concerned by the fundamental impossibility of assuring complete agreement between nodes operating in a distributed asynchronous environment, recognizing that this is assumed in the current most widely considered ideas for ongoing dynamic provisioning in optical networks. We describe a concept for handling dynamic provisioning changes and ongoing network reconfiguration and incremental reoptimization in general which avoids this hazard, and obtains other benefits in efficiency, through the use of precise network time to effect synchronous globally optimal ongoing reconfigurations of network state. A prime motivation is the dependency of existing concepts on the real-time coherence of databases of network state at diverse geographic locations. Not only is the continual updating of such global state everywhere in the network an intensive real-time load, but incoherencies are theoretically inevitable and pose unquantifiable hazards. The new scheme removes the database coherency hazard, reduces total signaling volumes, removes the need for any signaling which is realtime-critical, and increases resource efficiencies in service provisioning. It also provides a framework in general for continually ongoing incremental or (if desired) total reoptimization of network configuration. ¹