Efficient Probe Station Placement and Probe Set Selection for Fault Localization

Network fault management has been a focus of research activity with more emphasis on fault localization – zero down exact source of a failure from set of observed failures. Fault diagnosis is a central aspect of network fault management. Since faults are unavoidable in communication systems, their quick detection and isolation is essential for the robustness, reliability, and accessibility of a system. Probing technique for fault localization involves placement of probe stations (Probe stations are specially instrumented nodes from where probes can be sent to monitor the network) which affects the diagnosis capability of the probes sent by the probe stations. Probe station locations affect probing efficiency, monitoring capability, and deployment cost. We present probe station selection algorithms and aim to minimize the number of probe stations and make the monitoring robust against failures in a deterministic as well as a non-deterministic environment. We then implement algorithms that exploit interactions between probe paths to find a small collection of probes that can be used to locate faults. Small probe sets are desirable in order to minimize the costs imposed by probing, such as additional network load and data management requirements. We discuss a novel integrated approach of probe station and probe set selection for fault localization. A better placing of probe stations would produce fewer probes and probe set maintaining same diagnostic power. We provide experimental evaluation of the proposed algorithms through simulation results.