Local Recovery Solutions From Multi-Link Failures in MPLS-TE Networks With Probable Failure Patterns

MPLS TE Fast Reroute proposes a local protection mechanism to quickly reroute protected TE LSPs onto pre-computed and signaled bypass tunnels. This paper explores the case of multiple network element failure scenarios. The undesired complexity inherent to the multiple failure scenarios originates from the fact that those failure scenarios are more disruptive, and may require multiple bypass tunnels to cope with. The objective of this paper is to adapt the MPLS local recovery schemes to multi-failure scenarios, while controlling the number of bypass tunnels that are required. This objective is achieved by mapping multi-failure scenarios onto Probable Failure Patterns (PFP's). PFP's are characterized by their probability (or frequency) of occurrence during the network lifetime.