Abstract: A method includes obtaining first information indicative of instability of a data communication network. The method also includes isolating a first portion of a network from a second portion of the network responsive to the obtained first information. After a predetermined period of time, second information indicative of instability of the first portion is obtained. The method further includes isolating a first segment of the first portion from a second segment of the first portion responsive to the obtained second information.

Abstract: A method for provisioning a ring-based network is based on a routing of demands on shortest paths, according to a routing metric, and then assigning the routed demands to a collection of rings provisioned from a set of rings that meets preselected criteria, such as having less than a given number of nodes, and a mileage measure that is less than a given mileage upper threshold. The rings are provisioned to minimize a cost function that accounts for the cost of covering demands in rings, and the cost of failing to cover demands in rings. Further, an ordering of the traffic demands is determined that allows for routing as many traffic demands as possible.