K-Dimensional Trees for Continuous Traffic Classification

The network measurement community has proposed multiple machine learning (ML) methods for traffic classification during the last years. Although several research works have reported accuracies over 90%, most network operators still use either obsolete (e.g., port-based) or extremely expensive (e.g., pattern matching) methods for traffic classification. We argue that one of the barriers to the real deployment of ML-based methods is their time-consuming training phase. In this paper, we revisit the viability of using the Nearest Neighbor technique for traffic classification. We present an efficient implementation of this well-known technique based on multiple K-dimensional trees, which is characterized by short training times and high classification speed.This allows us not only to run the classifier online but also to continuously retrain it, without requiring human intervention, as the training data become obsolete. The proposed solution achieves very promising accuracy (> 95%) while looking just at the size of the very first packets of a flow. We present an implementation of this method based on the TIE classification engine as a feasible and simple solution for network operators.