On P4-based Reliability: Path Protection for Programmable Data Planes

This paper proposes a purposely designed 1+1 'Protection Header' (PH) protocol, guaranteeing traffic is delivered between two remote endpoints with no perceived packet loss in case of failures in the intermediate network. The protocol defines an Ingress Switch (IS), identifying the traffic to be protected and cloning it over two link-disjoint working and backup routes. An Egress Switch (ES) receives the duplicates and forwards the first copy after striping the protection information. We implemented the PH protocol on the Data Plane of SDN switches using the P4 programming language; then, we tested the protocol's operation on BMv2 switches in a virtual network. We showed that the proposed solution allows to successfully realise path protection between the source and the destination with no perceivable loss or delay in case of link failure.