Framework, models and controlled experiments for network troubleshooting

Our second contribution consists in a careful evaluation of the framework. Previous work on network troubleshooting has so far tackled the problem with either more theoretical or more practical approaches: inherently, evaluation methodologies lack either realism or control. In this paper, we counter this problem by conducting controlled experiments with a rigorous and reproducible methodology that contrasts expectations yielded by analytical models to the experimental results gathered running our NetProbes software in the Mininet emulator. As integral part of our methodology, we perform a thorough calibration of the measurement tools employed by NetProbes to measure two example metrics of interest, namely delay and bandwidth: we show this step to be crucial, as otherwise significant biases in the measurements techniques could lead to wrong assessment of algorithmic performance. Albeit our NetProbes software is far from being a carrier-grade solution for network troubleshooting (since it does not consider neither multiple contemporary measurements, nor multiple failures, and given that we experiment with a limited number of metrics), our controlled study allows making several interesting observation that help designing such an automated troubleshooting system.