I. Introduction
Traffic classification is fundamental to network management and security [1], which can identify different applications and protocols that exist in a network. For example, most QoS control mechanisms have a traffic classification module in order to properly prioritize different applications across the limited bandwidth. To implement appropriate security policies, it is essential for any network manager to obtain a proper understanding of applications and protocols in the network traffic. Over the last decade, traffic classification has been given a lot of attention from both industry and academia.