LiveNet: Using Passive Monitoring to Reconstruct Sensor Network Dynamics

We describe LiveNet, a set of tools and analysis methods for reconstructing the complex behavior of a deployed sensor network. LiveNet is based on the use of multiple passive packet sniffers co-located with the network, which collect packet traces that are merged to form a global picture of the network’s operation. The merged trace can be used to reconstruct critical aspects of the network’s operation that cannot be observed from a single vantage point or with simple application-level instrumentation. We address several challenges: merging multiple sniffer traces, determining sniffer coverage, and inference of missing information for routing path reconstruction. We perform a detailed validation of LiveNet’s accuracy and coverage using a 184-node sensor network testbed, and present results from a real-world deployment involving physiological monitoring of patients during a disaster drill. Our results show that LiveNet is able to accurately reconstruct network topology, determine bandwidth usage and routing paths, identify hot-spot nodes, and disambiguate sources of packet loss observed at the application level.