Fast and scalable multi-TCAM classification engine for wide policy table lookup

Abstract

With the explosive growth of Internet traffic, the next generation switches are designed to provide forwarding speed up to 10Gbps or above. To meet the challenges of delivering wire-speed deep packet inspection for various QoS requirements that making classification becomes the bottleneck of next generation high-speed switches. Ternary Content Addressable Memory (TCAM) provides high-speed parallel comparison operations and is one of the best candidates to implement next-generation hardware-based packet classifiers. Single-TCAM-based solution with ultra-high density has the advantage of simple architecture, but may not be feasible due to the scalability issue; also it may not be fast enough to fulfill the wide-policy-rule classifications, especial for the IPv6-based packets. To provide scalable and deep packet inspection, this paper proposes the pipeline architecture with multiple TCAMs to obtain wire-speed classification for IPv6 and multimedia applications. An algorithm to solve ambiguous cases among the rules is also proposed. Based on the proposed mechanisms, the packet classification engine capable of handling multiple QoS requirements at ultra-high speed is presented. © 2005 IEEE.