Speed Records in Network Flow Measurement on FPGA

Abstract

Network traffic measurement keeps track of the amount of traffic sent by each flow in the network. It is a core functionality in applications such as traffic engineering and network intrusion detection. In high-speed networks, it is impossible to keep an exact count of the flow traffic, due to limitations with respect to memory and computational speed. Therefore, probabilistic data structures, such as sketches, are used. This paper proposes Approximate Count-MM sketch or A-CM sketch, a novel variant of the Count-MM sketch algorithm that uses less memory and has a higher throughput compared to other FPGA-based sketch implementations. A-CM sketch relies on optimizations at two levels: (1) it uses approximate counters and the newly proposed Hardware-oriented Simple Active Counter algorithm to efficiently implement these counters; (2) it uses a distribution of the embedded memory, optimized towards maximum operating frequency. To the best of our knowledge, A-CM sketch outperforms all other FPGA-based sketch implementations.