Feature study on a programmable network traffic classifier

Monitoring and tracking of IP traffic flows are essential for network services (i.e. packet forwarding). Packet header lookup is the main part of flow identification by determining the predefined matching action for each incoming flow. In this paper, an improved header lookup and flow rule update solution is investigated. A detailed study of several well-known lookup algorithms reveals that searching individual packet header field and combining the results achieve high lookup speed and flexibility. The proposed hybrid lookup architecture is comprised of various lookup algorithms, which are selected based on the user applications and system requirements.

I. Introduction

Network traffic classification plays an important role in network nodes to support packet- and flow- processing functions, such as IP forwarding, packet filtering, security policies, quality of services, etc. Classifying input packets into flows and searching against pre-defined rules is a fundamental classification technique. An action is associated to each flow entry based on the same header fields and is determined by the first matching rule or the Highest-Priority Matching Rule (HPMR).