Backup Capacity Requirements for MPLS Fast Reroute

Conference: Photonische Netze - 7. ITG-Fachtagung
04/27/2006 - 04/28/2006 at Leipzig, Germany

Proceedings: Photonische Netze

Pages: 8Language: englishTyp: PDF

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Martin, Rüdiger; Menth, Michael (Department of Distributed Systems, Institute of Computer Science, University of Würzburg, Am Hubland, 97074 Würzburg, Germany)

MPLS fast reroute (MPLS-FRR) mechanisms deviate the traffic in case of network failures at the router closest to the outage location to achieve an extremely fast reaction time. We review and compare the one-to-one backup and the facility backup concept that are options for MPLS-FRR to deviate the traffic via a detour or a bypass, respectively. Basically, the backup paths can take the shortest path that avoids the outage location from the point of local repair to the tail-end router or to the merge point. We then evaluate the backup capacity requirements and the configuration overhead in terms of the number of backup paths per primary path in a parametric study depending on the network characteristics. While the facility backup concept imposes clearly less configuration overhead than the one-to-one backup, its standard path layout requires more capacity. This can be reduced by a simple modification.