D4VIS BLOG

About

Certain ISPs have been shown to rate limit or block BitTorrent traffic sent by their customers. While there are multiple reports of this on the web, only a few ISPs have admitted that they manipulate BitTorrent traffic. And, to date, it is hard for users without networking expertise to gain evidence about the behavior of their ISP.

This test suite creates a BitTorrent-like transfer between your machine and our server, and determines whether or not your ISP is limiting such traffic. This is a first step towards making traffic manipulation by ISPs more transparent to their customers.

What can you test?
Our test focuses on the popular BitTorrent protocol as many ISPs are suspected to manipulate BitTorrent traffic. This type of traffic can be identified by the port it is sent on (e.g., TCP port 6881) or by BitTorrent content headers which occur in the packets.
Therefore, we designed our online tool to detect whether your ISP is using one of the following techniques:

• Throttling all BitTorrent traffic.
  
• Throttling all traffic at well-known BitTorrent ports.
  
• Throttling BitTorrent traffic only at well-known BitTorrent ports.
  

Note that some ISPs do not throttle all BitTorrent traffic but only if this traffic exceeds a certain threshold. Thus, passing our tests does not necessary mean that there is no throttling occurring on your link.

• Our test runs BitTorrent and TCP downloads as well as uploads on a well-known BitTorrent port and a non-BitTorrent port.
  
• There are two test configurations available. The simple one takes approximately 4 minutes and each individual transfer is 10 seconds long. The full testset runs each transfer for 20 seconds and collect more data points and allows us to infer the status of your link with higher confidence.
  
• Note to all users: To allow accurate measurements you should stop any large downloads that might run in the background.
  
• If you are interested in a more detailed description of our test suite and its detection techniques, please read on here.