High speed IP lookup algorithm with scalability and parallelism based on CAM array and TCAM

With fast increasing of Internet's bandwidth, higher performance routers are needed, and their speed depends a lot on the IP routing lookup process. This paper proposes a high performance IP routing lookup algorithm based on CAM array and TCAM. Using smaller memory it does faster searching. For real route tables with 128K prefixes this scheme needs only 17 CAMs with total volume of 1.55 MB and a TCAM with 2K entries. It needs only 1 memory access time for each lookup and few memory accesses for each update in average. Using 10 ns CAM and TCAM, it can fully match the link speed of OC-768. For its good scalability and parallelism, it can be extended to adapt larger forwarding tables and faster forwarding requirements.