R-MPLS: recursive protection for highly dependable MPLS networks

Most modern communication networks feature fast rerouting mechanisms in the data plane. However, design and configuration of such mechanisms even under multiple failures is known to be difficult. In order to increase the resilience of the widely deployed MPLS networks, we propose R-MPLS, an alternative link protection mechanism for MPLS networks that uses recursive protection and can route around multiple simultaneously failed links. Our new R-MPLS approach comes with strong theoretical underpinnings, is implementable in a fully distributed way and executable on existing MPLS hardware, and formally guarantees that no forwarding loops are introduced. We implement our R-MPLS protection in an automated tool which overcomes the complexity of configuring such resilient network data planes, and report on the benefits of recursive protection in realistic network topologies. We find that R-MPLS significantly increases network robustness against multiple failures, with only moderate increase in the number of forwarding rules and communication overhead (both comparable to industry-standards like RSVP-TE FRR).