FBR: Dynamic Memory-Aware Fast Rerouting
Nicklas Slorup Johansen, Lasse B. Kar, Andreas Leicht Madsen, Kristian Ødum Nielsen, Stefan Schmid, Jǐŕı Srba, Rasmus Grønkjær Tollund · 2022
Modern internet communication networks, such as MPLS networks, provide fast rerouting mechanisms in the data plane in order to quickly react to link failures and hence become more dependable. However, fast rerouting requires additional memory for the conditional failover rules—a scarce and expensive resource. We initiate the study of memory-aware fast rerouting mechanisms and present Forward-Backward Routing (FBR), a dynamic rerouting approach with a provably high resilience to multiple link failures, which accounts for memory constraints on the routers. FBR relies on backtracking search along the routing paths via packet header modifications, and in our experimential evaluation on a wide range of ISP topologies, it outperforms state-of-the-art solutions while using less memory.