Performance Evaluation of TCAM Based Pattern-Matching Algorithm

With the increasing importance of network protection from cyber threats, it is required to develop a multi-gigabit rate pattern-matching method for protecting against malicious attacks in high-speed networks. This paper devises a high-speed deep packet inspection algorithm with TCAM by using an m-byte jumping window pattern-matching scheme. The proposed algorithm significantly reduces the number of TCAM lookups per payload by m times with the marginally enlarged TCAM size which can be implemented by cascading multiple TCAMs. Due to the reduced number of TCAM lookups, we can easily achieve a multi-gigabit rate for scanning the packet payload. Furthermore, multi-packet inspection is achieved easily by the extended state transition diagram with the shifting distance. With simulation results, we have clearly justified the proposed algorithm works well for a multi-gigabit network intrusion detection system.