Provisioning multilayer restoration for convergence

Abstract

Applications that require mission critical service will traverse multiple networks, which implement different protocol suites. Each layer in a suite has a recovery scheme that can reroute connections at that layer. We show that the solution to the repair of a fault that affects multiple layers lies in the provisioning of restoration at each layer to cooperate. Without some coordination between restoration mechanisms, an outage duration would be lengthened as methods assigned to each layer interfere with each other or 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 coordinate between restoration mechanisms in a network that spans multiple layers and regions. These control policies are expressed as rules, and are collectively denoted as the escalation strategy. The escalation strategy can be provisioned by a network manager and is implemented as a distributed coordination protocol between peer recovery agents in the nodes.