Intrinsically Resilient Optical Backbones: An Efficient RingBased Interconnection Paradigm Physical topologies are evolving from elementary survivable rings into complex mesh networks. Nevertheless, no topology model is known to provide an economic, systematic, and flexible interconnection paradigm for ensuring that those meshes bear resilience features. This paper argues that intrinsic resilience can be brought by twin graph topologies, as they satisfy equal length disjoint path property with minimal number of physical links. An exhaustive investigation is performed across twin graph families composing networks from 4 to 17 nodes, whereas diverse realworld topologies and ring networks are used as benchmarks. First, we illustrate the growing process, and discuss the topology diversity of twin graphs. We analyze the impact of single cable cuts between neighbouring nodes, then we stress topologies with 2, 3, and 4 simultaneous cable cuts. Improved resiliency is seen for neighbor nodes and also reduction of cut sets able to disconnect the twin topologies in comparison with realworld networks. Finally, we present as a use case the redesign of CESNET into a resilient network.

Graph Partitioning for Survivability in MultiDomain Optical Networks As optical networking deployments increase, multidomain provisioning and survivability are becoming major concerns. A key challenge in multidomain survivability is the scalability problem. To address this concern, various solutions have already been proposed based upon topology aggregation schemes. However, these mechanisms do not scale well with increasing domain counts and further investigation is required to develop more scalable alternatives. Along these lines, in this paper we propose to use graph partitioning techniques to solve the scalability problem in multidomain optical networks. To demonstrate the efficiency of our method, we also extend the pcycle concept to multidomain settings. Overall simulation results show the efficiency of our proposed solution in terms of resource utilization and the number of pcycle structures.