Analysis and Design of Backbone Architecture Alternatives for IP Optical Networking

The unprecedented growth of IP traffic is leading Internet Service Providers and network operators worldwide to investigate architectural alternatives for cost effective, reliable, scalable and flexible multi-terabit IP backbones. In this paper, several overlay, service and transport layer networking architectures, which employ IP, MPLS, SONET/SDH and DWDM technologies, are proposed and analyzed. Multiple parameters, such as network capacity, cost, restoration strategy, reconfigurability and accommodation of preemptable traffic, are considered for the architectural comparison. Detailed network design and economic analysis are provided for the different alternatives considering a typical nation-wide US backbone with projected IP traffic in approximately 3 years. Several sensitivity analysis results are also shown, to evaluate the effect of cost changes in some of the critical technological factors in these architectures, such as 10 Gb/s optics cost or IP router cost. The results show the value of transport layer networking architectures for multi-terabit IP backbones, and how, when compared with service layer architectures, they provide additional desirable features such as wavelength reconfigurability and restoration scaleability.