Scalable packet classification by TCAM entry encryption algorithm

Ternary content-addressable memory (TCAM) has been widely used to perform fast packet classification due to its ability of solving the problem in O(1) time without considering the number of entries, mask continuity and their lengths. However, it also comes with several shortcomings, such as the limited number of entries, expensive cost and power consumption. We propose an efficient algorithm to reduce the required TCAM bits by encoding the IP address portion of the policies. With the proposed scheme, the achieved compression ratio can be as small as 9% for IPv6 policies. Moreover, the TCAM throughput is improved by a factor of 175% with pipelining design. Obviously, the proposed scheme is attractive for the forthcoming IPv6.