A distributed cache architecture for routing in hierarchical QoS-capable networks

The route computing overhead caused by on-demand calculation of QoS routes, especially in large networks with heavy traffic, is a concern and can cause scalability problems. This paper introduces a distributed cache architecture to reduce the route computing load, caused by execution of QoS routing algorithms. The distributed nature of the proposed cache architecture facilitates its deployment in large networks. To maximize the performance of the distributed cache architecture, cache snooping has been proposed to alleviate the effects of changes in the network states. In performance evaluation of the proposed distributed cache architecture, we use a broad range of realistic network topologies, network traffic conditions, routing protocols, and aggregation techniques to evaluate different aspects of the proposed cache architecture under different conditions. The results confirm that the distributed cache architecture can significantly reduce the route computing overhead. In addition, our results suggest that the cache snooping can significantly increase the overall routing performance, especially in the presence of highly inaccurate network state information.