Ordered Lookup with Bypass matching for Scalable Per-flow Classification in Layer 4 Routers

Abstract

In order to provide different service treatments to individual or aggregated glows, layer 4 routers in Integrated Services networks need to classify packets into different queues. The classification module of layer 4routers must be fast enough to support gigabit links at a rate of millions of packets per second. In this work, we present a new software method OLBM to lookup multiple fields of a packet, in a dynamically pre-defined order, against the classification database. This algorithm can classify packets at a rate of well over 1 million packets per second while scaling to support more than 300K flows. Complexity analysis and experiment measurements are also presented in this study.