Visualization of broadband performance using M-Lab data

The charts presented in this page visualize various metrics computed using the data collected by NDT, one of the M-Lab tools. The values are visualized across countries, states, and cities and are aggregated by month. A team at Google created these charts using the NDT data publicly available on Google Storage.

You can find other visualizations on the M-Lab Charts web site.

Data

The aggregated data visualized in the following charts are available in csv format at https://sandbox.google.com/storage/#m-lab, ndt_pde_data folder. 

This document provides a detailed description of how the aggregated data are computed. 

This file lists all the ISPs visualized in the charts, and for each ISP, it lists all the ASes that are assigned to the ISP. The mapping ISP -> ASNs has been computed from bgp.potaroo.net/cidr/autnums.html.

Instructions (that apply to all the graphs in this page)

• Select “Explore data” on each map for more visualization options.
• You can change the month displayed by adjusting the bar at the bottom of the chart.
• You can change the location displayed by clicking the blue arrow in the “Compare” box (upper-left), and selecting any country, state, or city.
• You can select different chart types, by selecting one of the icons above the “Compare” box.

List of the charts:

• Download throughput map
• Network- versus client-limited tests
• Weighted receiver window scale rank
• Round trip time per M-Lab site
• Download throughput time distribution aggregated by ISP
• BitTorrent throttling by US ISP

A few notes to keep in mind before exploring these maps:

• Different speed tests measure network speed in different ways, producing some variations in reported results. NDT is an open-source test made available on the M-Lab platform. A description of the NDT methodology is available here.
• Server proximity can impact the accuracy of measured results. Being far from a testing server can results in lower values of measured speed. M-Lab has 48 servers throughout the US, Europe, and Australia, and we have chosen only to display speed measurements from these and nearby areas on the map.
• Any location in which we have insufficient data (fewer than 200 unique client IP addresses conducting measurements) is not visualized and its name be grayed out in the menu.

Median Download Throughput Map

Instructions

• The above chart shows the median download throughput aggregated by country.
• The download throughput is estimated by the NDT test, that measures the maximum amount of data that can be transferred from an M-Lab server to the user's device within a defined period fo time.
• Each bubble corresponds to a country. When you mouse over any bubble, the chart displays the name of the corresponding country.
• The color of the bubble represents the country download throughput, while the size of the bubble is proportional to the number of clients that ran the NDT test in that country.

Network- versus Client-Limited Tests

Instructions

• The chart above shows a distribution of countries by the median time spent by tests (run in those countries) in network or receiver-limited state.
• A test is in network limited state when the throughput is limited by congestion in the network. On the other hand, a test is in receiver-limited state when the user's device limits the throughput (for example, due to configuration errors).
• Each bubble corresponds to a country. When you mouse over any bubble, the chart displays the name of the corresponding country.
• The color of the bubble represents the country download throughput, while the size of the bubble is proportional to the number of clients that run the NDT test in that country.
• Bubbles at the top left correspond to countries where throughput is mostly limited by network congestion, while bubbles at the bottom right correspond to countries where throughput is mostly limited by the user's device.

Notes:

• In testing network and receiver limitations, NDT attempts to create congestion between a user’s machine and the M-Lab server. This serves as a “stress test” detecting the bottleneck of a connection as well as possible weak points.
• While running, a test can be in 3 states: network limited, receiver limited, and server limited. By design the latter state should not happen on the M-Lab platform (i.e., tests are never server limited, because M-Lab servers are specially provisioned). Therefore, the time ratio spent by each test in either net-limited and client-limited state.

Weighted receiver window scale rank

Instructions:

• The chart above ranks countries by their average received window scale value.
• The received window scale is the value negotiated at the beginning of a TCP connection to scale the receiver window size. The receive window size is the maximum amount of received data that can be buffered at one time on the receiving side of a TCP connection. 
• Each bar corresponds to a country. When you mouse over any bar, the chart displays the name of the correspondent country and (on the right) its RTT value. The color of the bar represents it’s median download throughput, with red being the fastest and blue being the slowest.

Round trip time per M-Lab site

Instructions:

• The chart above shows the median Round Trip Time (RTT) aggregated by M-Lab site.
• Each bubble corresponds to an M-Lab site and when you mouse over any bubble, the chart displays the name of the corresponding site.
• The color of the bubble represents the median RTT between the M-Lab site and the clients that ran a test against that site. The RTT is the amount of time that it takes for data to travel from the user's device (that is running the test) to an M-Lab server and back. The size of the bubble is proportional to the number of clients that run the NDT test in that country.

Download throughput time distribution aggregated by ISP

Instructions:

• The chart above shows the median download throughput for Greek users, aggregated by ISP (Internet Service Provider). In particular, for every ISP, all the measurements run by clients in the ASes (Autonomous Systems) assigned to that ISP are aggregated together. This file lists all the ISPs visualized in the charts, and for each ISP, it lists all the ASes that are assigned to the ISP. The mapping ISP -> ASNs has been computed from bgp.potaroo.net/cidr/autnums.html. 
• Each line corresponds to an ISP and connects various points. Each point corresponds to the median download throughput measured during a month. When you mouse over a point, the chart displays the corresponding throughtput value.
• It is possible to compare the download throughput (and other metrics) provided by different ISPs within the same country, region (state in the US), and city, by selecting ISPs in the left menu bar (visible only after you click on "Explore data"), taking into considerartion that the visualizations do not take account explicitly for differences in service tiers and technologies (e.g., ADSL vs Cable). Whether or not an ISP is delivering the service advertised within a specific tier is not reflected here; an ISP that is delivering good service to customers at a low service tier may rank lower than an ISP delivering poor service to customers at a high service tier. 

BitTorrent Throttling by US ISPs

Instructions

• The above chart shows the percentage of times US ISPs manipulated BitTorrent traffic from Q2 2008 through Q2 2010.
• Traffic manipulation is determined using the Glasnost test, which attempts to determine whether an Internet access provider is performing application-specific traffic shaping.
• Each bar represents a US ISP; hover over the bar for the ISP's name and exact throttling percentage.
• The left axis shows the percentage of times throttling occurred; the lower axis shows time.
• Comparative data and visualizations for other countries are available at http://dpi.ischool.syr.edu/MLab-Data.html.