You have likely heard rumors and may have even seen evidence now and then — some internet providers will slow down some traffic types, for example, BitTorrent traffic. Then again, other ISPs will slow connections if they download too much data.
Does your ISP do this? Here are some simple things you can do to test whether your ISP is traffic shaping or doing any bandwidth throttling on your service.
How to test for traffic shaping
To test if your ISP is slowing your internet connection down over time, you will need to monitor your connection speed over a period of time. For example, if your ISP slows down your internet speed, it’s likely to happen towards the end of the month after you have used up a large amount of data. And typically, it will be faster at the beginning of the following month.
You can also monitor variations in internet speed over time. Run the test at the start of the month and then regularly run additional tests, especially when the end of the month arrives. If you are consistently seeing speeds that are slower close to the end of the month, it’s likely your ISP is throttling your bandwidth.
You should know that there are some factors that might affect the results of your speed tests. For example, if you or others on your network download or upload on your connection, it is possible that the measurement isn’t accurate. It is best to perform the speed test when no one is using the connection.
In addition, the time of day may have impact on the speed of your internet connection. Speeds may be much faster at 4 a.m. when there is no one else on the shared ISP line rather than at 8 p.m. when far more people in your neighborhood are browsing the net.
Additional monitoring tools
The Measurement Lab (M-Lab) offers a number of additional tools you can use to track internet connection data, measure network performance, diagnose network problems, and test for traffic shaping. If you want to use additional tools to test your connection speed, this would be a good starting point.
Glasnost service offers web-based tests that will help you identify various traffic types that could be limited. For example, run both Glasnost and the BitTorrent test to learn whether your ISP is slowing down your BitTorrent transfers. Glasnost is also able to run tests that can detect whether Flash video, eMule, Gnutella, HTTP, Email Usenet, or SSH are being blocked or throttled by your ISP. It takes about 8 minutes to run each of the tests.
Unfortunately, if your ISP throttles your connection, there really is not a lot you can do. You could change ISPs and try to find one that treats you better, providing your ISP does not have a monopoly in your area, which is far too common. You could also pay more and get a more expensive plan that provides you with a higher bandwidth allocation and, hopefully, does no traffic shaping.