Evaluation of IP-over-DWDM core network architectures with CD-ROADMs using IP protection in combination with optical restoration

New optical technologies allow a more dynamic mode of operation of IP-over-DWDM networks. In addition to reducing operational expenditures, the flexible optical layer can be used to offer differentiated multilayer resilience combining IP protection with optical restoration in IP-over-Optical networks. After a short overview on the key enabling technologies for flexible IP-over-DWDM interworking, the authors will give guidelines for the cost-efficient IP topology design of multilayer IP-over-DWDM core networks and show that for a German backbone reference network the combination of IP A/B-plane protection with optical restoration requires 24-27% fewer line interfaces compared to the multilayer optimized bypass network design.