Efficient selection of optimally designed ethernet ring instances

Ethernet Ring Protection (ERP) switching has emerged to provide sub-50ms of restoration times, allowing Ethernet technologies to expand beyond enterprises to Next Generation Metro and Backbone networks, providing much needed services to interconnect dispersed data centers. This paper considers the problem of efficiently designing and planning an Ethernet based metro network with ERP protection method. While previous recent work has addressed such design problem, none has considered the capabilities of exploiting multiple ERP instances, leaving behind some advantages that network providers could tap into to providing their customers with desirable quality of service support. Resource planning in ERP based Ethernet networks is however a complex problem due to the challenges associated with the logical link block selection as well as ring hierarchy selection. ERP instances add however another dimension of combinatorial complexity, making the design problem completely intractable. To address this issue, we resort to large scale optimization tools and present a novel primal-dual decomposition of the original problem using column generation. We show that our method is very scalable and obtain several design insights on various representative network instances.