Pinpointing Delay and Forwarding Anomalies Using Large-Scale Traceroute Measurements

Speaker : Cristel Pelsser
Université de Strasbourg
Date: 23/11/2016
Time: 2:00 pm - 3:00 pm
Location: LINCS Meeting Room 40


Understanding network health is essential to improving Internet reliability. For instance, detecting disruptions in peer and provider networks identifies fixable connectivity problems. Currently this task is time consuming as it involves a fair amount of manual observation because operators have little visibility into other networks.Here we leverage existing public RIPE Atlas measurement data to monitor and analyze network conditions; creating no new measurements. We demonstrate a set of complementary methods to detect network disruptions using traceroute measurements. A novel method of detecting changes in delay is used to identify congested links, and a packet forwarding model is employed to predict traffic paths and to identify faulty routers and links in cases of packet loss. In addition, aggregating results from each method allows us to easily monitor a network and identify coordinated reports manifesting significant network disruptions, reducing uninteresting alarms.Our contributions consist of a statistical approach to providing robust estimation or Internet delays and the study of hundreds of thousands link delays. We present three cases demonstrating that the proposed methods detect real disruptions and provide valuable insights, as well as surprising findings, on the location and impact of identified events.