Scalable Packet Classification: Cutting or Merging?

Multi-field packet classification is a fundamental function that enables routers to support a variety of network services. Most of the existing multi-field packet classification algorithms can be divided into two classes: cutting-based and merging-based solutions. However, neither of them is scalable with respect to memory requirement for all rule sets with various characteristics. This paper makes several observations on real- life rule sets and proposes a novel hybrid scheme to leverage the desirable features of the two classes of algorithms. We propose a SRAM-based parallel multi-pipeline architecture to achieve high throughput. Several challenges in mapping the hybrid algorithm onto the architecture are addressed. Extensive simulations and FPGA implementation results show that the proposed scheme sustains 80 Gbps throughput for minimum size (40 bytes) packets while consuming a small amount of on-chip resources for large rule sets consisting of up to 10 K unique entries.