TCAM co-processor for packet classification

Abstract

The process of categorizing packets into "flows" in an Internet router is called packet classification. All packets belonging to the same flow obey a predefined rule and are processed in a similar manner by the router. With the increasing number of Internet applications and users, IPv6 is required due to an increased amount of IP addresses. In the mean time, state-of-the-art network technologies require wire-speed classification performance. In order to meet these new challenges, a new encoding scheme is necessary. In my project, I propose a new multi-field classification scheme, called prefix inclusion coding (PIC), using standard Ternary Content Addressable Memory (TCAM) as a hardware classification engine. Another classification scheme, Parallel packet classification (P2C), is brought to a detailed implementation to compare with the new scheme mainly in terms of code word length and update performance. As a result, I find the new scheme largely reduce the code word length as well as hardware cost. Moreover, the result indicates that P2C is not that satisfying in update performance and too complicated for real life usage due to the specified hardware, BART, it uses.