InFaRR: In-Network Fast ReRouting

Abstract

InFaRR (In-network Fast ReRouting) is an algorithm for fast rerouting in programmable data planes. Implemented in P4, InFaRR is free of additional headers and network state heartbeats. InFaRR has four essential features not jointly found in other recovery mechanisms: Loop prevention, Pushback, Recognition and Restoration and Return to the main route. Tests in standard Fat-Tree and AB Fat-Tree topologies with failures in different scenarios showed positive results when compared to state-of-the-art algorithms in the literature. In scenarios in which the other algorithms were able to recover, InFaRR presented fewer hops to bypass the failure when the Pushback, Loop Prevention and Recognition and Restoration mechanisms were used. In scenarios with multiple failures, InFaRR successfully rerouted where the others algorithms in some cases looped. The mechanism for returning to the main route allows to verify failures in remote links, making it possible to return to the main route without intervention from the control plane. Several evaluations were done comparing the results of InFaRR with the state-of-the art mechanisms, showing the capability of our fast rerouting algorithm in dealing with failures at the line-rate.