Efficiency analyses on routing cache replacement algorithms

Recent research on router architectures focuses on speeding up the time-consuming routing-lookup procedure by elaborate algorithms and data structures to match the ever-increasing wire-speed of fiber links. However, we observed strong temporal locality in the traffic traces collected from two TANet backbone routers. Thus, a routing cache, which is used to reuse previous routing-lookup results, can significantly offload the routing-lookup module. In this paper, we first introduce our temporal locality analysis. Then we investigate the efficiency of several routing cache replacement algorithms, which includes FIFO, LRU, random and our proposed LFU implementation alternative. The simulation results show that our proposed exponentially decayed LFU scheme provides better performance than the other algorithms, especially under small-size caches.