LOP: A packet classification architecture with higher throughput and lower power consumption than TCAM

Abstract

Packet classification is an important method implemented in modern network processors used in embedded systems such as routers. Current software-based packet classification techniques exhibit low performance, prompting researchers to move their focus to architectures encompassing both software and hardware components. Some of the newer hardware architectures exclusively utilize Ternary Content Addressable Memory (TCAM) to improve the performance of rule matching. However, this results in systems with high power consumption. In this paper, we propose LOP, a novel SRAM-based architecture where incoming packets are compared against parts of all rules simultaneously until a single matching rule is found for the compared bits in the packets. LOP significantly reduces power consumption as only a segment of the memory is compared against the incoming packet. Despite the additional time penalty to match a single packet, parallel comparison of multiple packets can improve throughput beyond that of the TCAM approaches, while consuming significantly less power. Compared with a state-of-the-art TCAM implementation (throughput of 495 Million Search per Second (Msps)) in 65 nm CMOS technology, on average, LOP saves 43% of energy consumption with a throughput of 590 Msps. In addition, an analysis of how the area scales is provided.