A Novel Approach for Reducing HSR Unicast Traffic Using Pre-defined Dual Paths

Abstract

High-availability seamless redundancy (HSR) is a redundancy protocol for Ethernet networks that provides zero recoery time in case of a network failure. The feature of HSR makes it suited for time-critical and mission-critical applications, such as substation automation systems and military applications. However, the standard HSR protocol excessively generates unnecessary unicast traffic by redundant frame copies. This unnecessary redundant traffic causes high bandwidth consumption, resulting in the degradation of network performance. In this paper, we introduce a novel approach called ring-based dual paths (RDP) to reduce unnecessary unicast traffic in HSR networks. The purpose of RDP is to establish dual paths for forwarding unicast frames between nodes in HSR networks. Unlike dual virtual paths (DVP) approach, which establishes dual paths for each connection pair of terminal nodes, RDP sets up dual paths for each connection pair of terminal rings. Therefore, RDP significantly reduces control overhead in discovering and establishing dual paths, as well as the memory space required to store these paths compared with the DVP approach. The performance of RDP has been analyzed, evaluated, and compared to that of standard HSR protocol and the DVP approach. Simulations were conducted to validate the traffic performance analysis. The analytical and simulation results showed that, for our sample network, RDP reduced network unicast traffic by about 78% compared with standard HSR protocol, thus freeing up network bandwidth and improving network traffic performance.