High-Throughput Exact Matching Implementation on FPGA with Shared Rule Tables Among Parallel Pipelines

Abstract

In software defined network (SDN). packet processing is commonly implemented using match-action model. where packets a.re processed based on matched actions in match action table. Due to the limited FPGA on-boa.rd resources, it is an important challenge to achieve largescale high throughput based on exact matching (EM), while solving hash conflicts and out-of-order problems. To address these issues, this study proposed an FPGA-based EM table that leverages shared rule tables across multiple pipelines to eliminate memory replication and enhance overall tlnoughput. An out-of-order reordering function is used to ensure packet sequencing within the pipelines. Moreover, to handle collisions and increase load factor of hash table. multiple hash table blocks are combined and an auxiliary CAM-based EM table is integrated in each pipeline. To the best of our knowledge, this is the first time that the proposed design considers the recovery of out-of-order operations in multi-channel EM table for high-speed network packets processing application. Furthermore, it is implemented on Xilinx Alveo U250 field programmable gate arrays. which has a million rules and achieves a processing speed of 200 million operations per second, theoretically enabling tlnoughput exceeding 100 Gbps for 64-Byte size packets.