MPLS Protection Switching Versus OSPF Rerouting

Abstract

Resilience is becoming a key design issue for future IP-based networks having a growing commercial importance. In the case of element failures the networks have to reconfigure in the order of a few hundred milliseconds, i.e. much faster than provided by the slow rerouting of current implementations. Several multi-path extensions to IP and timer modifcations have been recently proposed providing interesting alternatives to the usage of of MPLS below IP. In this paper these approaches are first described in a common context and then compared by simulations using very detailed simulation models. As one of the main results it can be shown that an accelerated update of the internal forwarding tables in the nodes together with fast hardware-based failure detection are the most promising measures for reaching the required reconfiguration time orders.