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—We describe a novel restoration strategy called virtual protection cycles (cycles , patents pending) for extremely fast restoration in IP networks. Originally conceived for use in WDM and Sonet transport networks, we outline the adaption of the-cycle concept to an IP environment. In an IP router-based network ,-cycles are implemented with virtual circuits(More)
Cycle-oriented preconfiguration of spare capacity is a new idea for the design and operation of mesh-restorable networks. It offers a sought-after goal: to retain the capacity-efficiency of a mesh-restorable network, while approaching the speed of line-switched self-healing rings. We show that through a strategy of pre-failure cross-connection between the(More)
– In the modern business environment for optical mesh networking, there is considerable interest in being able to support a range of service classes, and to charge accordingly. In this work we consider the capacity design problem for different combinations of four protection priority classes in a span-restorable mesh network. Most significantly we have(More)
—Recent work on restorable networks has shown experimentally that one can support 100% restoration with an optimized set of closed cycles of spare capacity while requiring little or no increase in spare capacity relative to a span-restorable mesh network. This is important and unexpected because it implies that future restoration schemes could be as(More)
We evaluate the performance of optical network designs using relatively few switch nodes at which wavelength conversion and electronic regeneration is possible. A simple heuristic for placing the fewest such nodes to reach a given blocking probability is based on the ranked frequency of shortest-path routes transiting each node. This strategy is found to be(More)
This article is devoted to a selection of recent topics in survivable networking. New ideas in capacity design and ring-to-mesh evolution are given, as well as a systematic comparison of the capacity requirements of several mesh-based schemes showing how they perform over a range of network graph connectivi-ty. The work provides new options and insights to(More)
urvivability considerations are increasingly important as the capacities of optical networks continue to grow, enabling ever greater demand quantities to be carried on a single fiber. Protection and restoration mechanisms are a key aspect in the design of such high-capacity optical networks and can significantly impact not only restoration speeds and(More)