On improving partial information routing with segmented path protection

Abstract

Changing trends in backbone transport networks towards dynamic path provisioning and evolving optical technologies have motivated the study of dynamic routing algorithms in the context of Multi Protocol Label Switching (MPLS) based networks. The author previously developed dynamic algorithms for source based routing with partial information (2002). Our studies showed that dynamic routing algorithms perform better than static routing algorithms using precomputed paths even when the path selection in static algorithms is based on optimizing a global network metric. Since we rely on partial information for making dynamic routing decisions, the capacity redundancy in the network is high. In this paper, we propose a dynamic routing algorithm that uses a simple segmented path protection scheme to improve capacity efficiency. We compare the performance of the partial information routing algorithm with and without segmented path protection through simulation studies, based on metrics such as the call blocking probability and capacity redundancy. Our results indicate that with a simple segmentation scheme, the capacity efficiency of partial information routing can be significantly improved, up to 20 to 30% depending on the topology. The capacity savings obtained leads to a modest improvement in call blocking. It is also observed that segmented protection offers better performance as compared to path protection under partial information scenario, which is contrary to the performance obtained with complete information. Hence, it would be a better alternative to employ segmented protection in large networks where obtaining complete network state information is impractical.