Tuning Active Monitoring in Multi-service IP Networks

This paper explores the use of edge-to-edge active monitoring to control simultaneously multiple QoS parameters in multi-service IP networks, while reducing the effects of intrusion on real traffic. Considering a multi-class domain where traffic is controlled at network boundaries based on feedback from on-line measurements, the present work is centered on obtaining adequate per class in-band probing streams so that each class behaviour is correctly captured, even if more than a QoS metric is under control. In this way, we investigate distinct properties of probing patterns and cross-check probing and passive measurement results in order to assess and tune probing effectiveness. To enhance probing ability to sense multiple metrics, we explore Active Queue Management effects on probes and their different probability of reaching the network boundary. The results show that, while IPTD can be easily captured using a very low probing rate, matching ipdv and IPLR is not straightforward. However, we found that choosing a convenient drop precedence for probing packets, the simultaneous estimation of these QoS metrics can be significantly improved.