TCAM-Hash: A Combined Routing Lookup for Network Applications

Abstract

The latency and resource consumption are significant factors for routing lookup (RL) in network applications. This paper proposes a combined RL strategy (TCAM-Hash), which utilizes the advantages of both TCAM- based and hash-based RL. The hash module solves the RL for over 90% of network rules. The TCAM module solves the RL for the rest rules. In the FPGA experiment, the hash module supports the RL for wide input rules (144-bit), achieves very low latency (12.8 ns), and costs very limited FPGA resources (2.5 BRAM and 664 LUT).