Defining provably-correct escalation policies for multilayer network restoration

Automatic protection switching (APS) protocols assigned to different layers in wide-area networks require interworking functionality in order to restore a wide variety of services and accommodate an evolving network infrastructure. Without some coordination between restoration mechanisms, an outage duration would be lengthened as methods assigned to different layers interfere with each other, and the network would be locked up in a deadlocked state that never converges to a new topology. A set of control policies can be specified to schedule different restoration mechanisms in a network that spans multiple layers and administrative boundaries. These control policies, which are expressed as if-then rules, are denoted as the escalation strategy. As rules for coordinating between restoration mechanisms are formally expressed in a policy definition language, a mathematical proof could be provided to prove that the agents have consistent knowledge of the network state, allowing individual APS protocols to cooperate with each other