Measurement and Experimentation from the Edge

Turning end hosts into a measurement platform with a view no testbed can buy.

Project Overview

For a long time, measuring the Internet meant measuring it from the places researchers could get accounts: universities, research networks, and testbeds sitting a short hop from a well-provisioned backbone. Those vantage points are convenient and unrepresentative. The paths that matter to users start behind a home router, on a residential access link, at the far end of the network from anything a testbed can see.

This project took the position that the interesting vantage point is the edge, and that the way to reach it is to ride along with software people already run. Rather than asking users to install a measurement tool, we built measurement into applications they were using anyway — which changed both the scale and the realism of what we could observe, and forced us to take seriously the problem of being a good guest on someone else’s connection.


Two Projects

The thread produced two efforts substantial enough to stand on their own.

NEWS came first. Its premise was that a peer-to-peer application already maintains connections to many peers across many networks, and already knows how those connections are performing — in effect a continuous distributed measurement of the network, generated for free as a side effect of normal use. By looking for correlated performance changes across a peer’s connections, and corroborating across users in the same ISP or country, NEWS detected service-level network events from the edge with no probes and no infrastructure.

Dasu carried the approach into experimentation. It began as an ISP characterization tool — measuring the broadband service a user actually received, from inside the home, across many providers and countries — and became a platform that could host other researchers’ experiments from tens of thousands of real access links, with the scheduling and safeguards that hosting implies when the machine belongs to a volunteer.

Both are documented on their own pages; what follows is the tooling that supported them.


Software

  • The Nixes Tool Set — bash scripts to install, maintain, control and monitor applications on PlanetLab, used to deploy the wide-area experiments behind this work.

The measurement clients themselves — the Vuze plugins and the Dasu standalone client — are described on the NEWS and Dasu pages.


Papers


Coverage

NEWS was covered by RedOrbit, Slashdot, and The Hindu in 2008.


People

Lead & PI

Students

Collaborators

  • Balachander Krishnamurthy (AT&T Labs–Research)
  • Walter Willinger (AT&T Labs–Research)