FCC and M-Lab Collaboration


  1. About M-Lab
  2. About NDT
  3. Common NDT Warnings and Errors
  4. About Data

About M-Lab

The FCC's Consumer Broadband Test utilizes the Network Diagnostic Tool - an open-source tool created by Internet2 and hosted by Measurement Lab (M-Lab). M-Lab is an open, distributed server platform for researchers to deploy Internet measurement tools. M-Lab is a collaborative effort led by academic researchers in partnership with New America Foundation's Open Technology Initiative, the PlanetLab Consortium, Google Inc., and other supporting companies and institutions.

You can learn more about M-Lab here.

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About NDT

Network Diagnostic Tool (NDT) provides a sophisticated speed and diagnostic test. An NDT test reports more than just the upload and download speeds -- it also attempts to determine what, if any, problems limited these speeds, differentiating between computer configuration and network infrastructure problems. It was written by Rich Carlson and volunteer contributors and is maintained by Internet2.

While the FCC's website only exposes a few of the metrics NDT collects (upload and download speed, latency and jitter), you can see the full functionality of the tool by running the test here.

For more information, also see NDT's website.

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Common NDT Warnings and Errors

This section compiles a list of common NDT warnings and errors.

Java Security Warning for Tcpbw100: The application's digital signature has been verified. Do you want to run the application?

This warning is actually just a notice, letting users know that NDT uses a signed-Java client applet Tcpbw100. This applet is signed by the New America Foundation, whose Open Technology Initiative is a partner in Measurement Lab. The signed applet assures the user that what they are running is the code that was released by Measurement Lab, and not something else. This certificate guarantees the authenticity of the test, and is required by some NDT integrators. While some earlier versions of the Sun Java Runtime Environment will not display the notice when encountering NDT, the most up-to-date versions will. Users encountering a the above notice, letting them know that the app has been signed, should choose Run to allow NDT to run normally.

NDT message: Another client is currently being served, your test will begin within NNN seconds

To ensure accurate