A NOVEL FILTERING TECHNIQUE FOR REDUCING REDUNDANT UNICAST TRAFFIC IN HSR NETWORKS

摘要

High-availability seamless redundancy (HSR) is one of the seamless redundancy protocols providing fault-tolerance for Ethernet networks. HSR is very useful for applications that demand high availability with fault-tolerance. However, redundant unicast traffic is excessively generated in HSR networks. This drawback causes high consumption of network bandwidth and may degrade network performance in HSR networks. In this paper, we propose a novel single-filtering technique called FQR that filters unicast frames for unused QuadBox rings in HSR networks. The FQR technique reduces duplicated unicast frames in an HSR network by filtering the frames for passive QuadBox rings that are not used to forward the unicast frames for a communication session between a source and a destination in the network. The FQR uses a simple mechanism to discover passive QuadBox rings and then prevent QuadBoxes from forwarding unicast frames into the passive QuadBox rings. By pruning unicast frames for passive QuadBox rings, the proposed technique dramatically decreases duplicated unicast frames in HSR networks compared to the standard HSR protocol. Traffic performance of FQR is analyzed and several simulations were carried out to validate the analysis. Numerical results showed that, for the sample network used in this paper, network unicast traffic under the proposed technique was reduced by 37% compared to that under the standard HSR protocol, resulting in the save of network bandwidth and the improvement of network traffic performance. The proposed single-filtering technique can be combined with other single-filtering techniques to propose a very effective combined-filtering technique for HSR networks.