Abstract

Proceedings of 11th International IFIP TC6 Conference, ONDM 2007, Athens, Greece, May 29-31, 2007. The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-540-72731-6_46 Typically, core networks are provided with both optical and electronic physical layers. However, the interaction between the two layers is at present limited, since most of the traditional transport functionalities, such as traffic engineering, switching and restoration, are carried in the IP/MPLS layer. In this light, the research community has paid little attention to the potential benefits of the interaction between layers, multilayer capabilities, on attempts to improve the Quality of Service control. This work shows when to move incoming Label Switched Paths (LSPs) between layers based on a multilayer mechanism that trades off a QoS metric, such as end-to-end delay, and techno-economic aspects. Such mechanism follows the Bayesian decision theory, and is tested with a set of representative case scenarios. The authors would like to thank the support from the European Union VI Framework Programme e-Photon/ONe+ Network of Excellence (FP6-IST-027497). This work has also been partially funded by the IST Project NOBEL II (FP6-IST-027305). Document type: Part of book or chapter of book

Abstract

Large IP backbone networks today are mostly deployed directly over sequences of point-to-point DWDM systems or chains of newer ROADM-based ultra long haul systems, interconnected by OEO regenerators. The next generation core optical network is moving toward an all-optical network architecture that is based on multi-degree ROADMs to reduce OEO regeneration cost as well as enabling automatic reconfigurability and dynamic restoration. In this paper, we study the restoration design in this new IP over reconfigurable all-optical network architecture to satisfy the resilience requirements for both IP and wavelength services. We propose two novel restoration schemes: 2-Phase Fast Reroute mechanism with optimized Traffic Engineering algorithm for restoring IP services and shared mesh restoration with standbys for restoring wavelength services. They both meet the requirement of sub-second restoration time and also maximize sharing among different failures with the objective of minimizing either overall capacity or overall cost. To further reduce the required restoration capacity in both IP layer and optical layer and address failures in both layers efficiently, we also propose an integrated IP-over-optical layer restoration strategy that enables sharing of restoration capacity among non-simultaneous failures across both IP and optical layers. Simulation results demonstrate significant improvements using our proposed schemes comparing with existing ones. Document type: Part of book or chapter of book