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Measurement Lab (M-Lab) Application & Methodology

More About Network Diagnostic Tool (NDT) and Measurement Lab (M-Lab)
(Description provided by M-Lab)

NDT is a network performance testing system that allows end-users to attempt to identify computer configuration and network infrastructure problems that degrade their broadband experience. NDT is an open source project that is under active development by Internet2.

The FCC Consumer Broadband Test takes advantage of the NDT instances running on M-Lab, which 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. The goal of M-Lab is to advance network research and empower the public with useful information about their broadband connections. In order to advance network research, M-Lab makes the results of all tests publicly accessible and available for others to re-use. Note that your address and zip code are not shared back with M-Lab, and only the results of the broadband test will be collected and made public. The test-resulting data collected via M-Lab is not personally identifying.

Measurement Lab can be reached at measurementlab.net.

M-Lab Methodology:

When the user activates the M-Lab NDT application a Java Applet is downloaded onto the client’s computer. The applet communicates with the server to run a series of short tests, as follows:

Download Test

  • A block of pseudo random data is generated on the server and stored in memory.
  • The server repeatedly transmits this data to the Java client for 10 seconds.
  • The client acknowledges receipt of this data and then discards it.
  • The server calculates the average throughput by dividing the number of bytes sent by the test time.
  • The server also makes measurements on a per-packet basis, calculating the capacity of the end to end path.
  • The server measures the number of lost and delayed packets, the instantaneous round trip time, and examines the clients network configuration to determine what, if anything, caused a drop in the expected throughput.
  • Multiple clients may be served simultaneously.

Upload Test

  • A block of pseudo random data is generated on the client and stored in memory.
  • The client repeatedly transmits this data to the server for 10 seconds.
  • The server acknowledges receipt of this data and then discards it.
  • The server calculates the average throughput by dividing the number of bytes sent by the test time.
  • The server also makes measurements on a per-packet basis, calculating the capacity of the end to end path.
  • Results from the test are returned to the client at the conclusion of the test.

Latency/Jitter

  • Multiple measurements of the round trip delay and per-packet transmission/arrival times are collected.
  • The delay for each measurement is summed and divided by the total number of measurements to generate the average round trip delay.

View NDT Common Warnings and Errors

Capture The Phone Numbers Using Your Camera Phone

If you have a camera and a 2D matrix code reader on your mobile phone, you can capture the FCC Phone numbers right to your phone by following these three easy steps:
Step 1: Take a photograph of one of the codes below using the camera on your mobile phone.
Step 2: Use your phone's Datamatrix or QR Code reader to decode the information on the photograph. Please note, these code readers are device specific and are available to download on the internet.
Step 3: Store the decoded address information to your phone's address book and use it with your Maps or GPS application.

Datamatrix and QR FCC Phones