Reconfiguration Based Failure Restoration in Wavelength-Routed WDM Networks

• Authors: G. Sai Kiran Reddy;C. Siva Ram Murthy;G. Manimaran
• Venue: DSN '00 Proceedings of the 2000 International Conference on Dependable Systems and Networks (formerly FTCS-30 and DCCA-8)
• Year: 2000

Wavelength-division multiplexed (WDM) optical networks using wavelength routing are considered to be a potential candidate for next generation wide-area backbone networks. The key component in such networks is the lightpath network (LPN) manager. The functions of the LPN manager include setting up the logical topology, sustaining the network by monitoring traffic and network parameters, and handling node and/or link failures. Failure handling in WDM networks is of prime importance due to the nature and volume of traffic these networks carry. Failure detection is usually achieved by exchanging control messages among nodes with timeout mechanisms. Failure restoration can be done either by rerouting only the failed lightpaths (LPs) or by reconfiguring all the existing LPs in the network. The reconfiguration approach involves finding new LPs in the faulty network ({\it LP design}) and realizing these new LPs by selectively removing the old LPs ({\it LP realization}) with the objective of minimizing the service disruption to the ongoing calls. The existing work on reconfiguration approach considers only the LP design and ignores the LP realization. In this paper, we first propose architecture for the LPN manager highlighting the importance of LP realization in the reconfiguration based failure restoration, and then propose performance measures and heuristic algorithms for LP realization. We evaluate the effectiveness of the LP realization algorithms through simulation studies.