A practical and effective approach to implementing High Availability Seamless Redundancy (HSR)

Abstract

High availability Ethernets are being used for many industrial automation applications, and the adoption of High Availability Seamless Redundancy (HSR) is gaining strong interests from both the industry and academics as it is able to achieve zero recovery time. This paper presents a simple, practical, and effective implementation of HSR based on Add-Drop-Multiplexer (ADM). A major contribution of the paper is to use polling, instead of the legacy MAC learning process, to build the MAC forwarding table on RedBox and QuadBox. Through our simulation model, we demonstrate the effectiveness of this approach to (1) avoid loops of broadcast messages, (2) identify redundant packets, and (3) achieve zero recovery time.