A new IP lookup cache for high performance IP routers

IP lookup is in the critical data path in a high speed router. In this paper, we propose a new on-chip IP cache architecture for a high performance IP lookup. We design the IP cache along two important axes: cache indexing and cache replacement policies. First, we study various hash performance and employ 2-Universal hashing for our IP cache. Second, coupled with our cache indexing scheme, we present a progressive cache replacement policy by considering Internet traffic characteristics. Our experiments with IP traces show that our IP cache reduces the miss ratio by 15% and a small 32KB IP cache can achieve as high as 2Tbps routing throughput.