Scalable memory-less architecture for string matching with FPGAs

String matching hardware engines generally utilize Ternary Content Addressable Memories (TCAMs). Although TCAM-based solutions are fast, they are expensive and power hungry. This paper proposes a high-performance memory-less architecture for string matching called Split-Bucket. It offers a performance comparable to TCAM-based solutions. Moreover, it is reconfigurable and scalable to the size of the target string set and the width of the string. The architecture is characterized using the Longest Prefix Match problem for IP address lookup and is implemented on a Virtex-7 FPGA. For a real-world routing table with 524 k IPv4 prefixes, the Split-Bucket architecture achieves a throughput of 103.4 M packets per second and consumes 23% and 22% of the Look Up Tables and Flip-Flops of a Xilinx XC7V2000T chip, respectively.