A report from From the Max Planck Institute for Software Systems: Glasnost: Results from Tests for BitTorrent Traffic Blocking
More than 8,000 users from locations around the world have used our tool, Glasnost, to test whether their BitTorrent traffic is being manipulated. On this page, we present preliminary results from these tests. The tests were conducted between March 18th and May 15th 2008.
All hosts which observed blocking did so in the upstream direction (i.e., when the client host attempted to upload data to one of our Glasnost servers). Only a handful of hosts observed blocking for downstream BitTorrent transfers.
We found widespread blocking of BitTorrent transfers only in the U.S. and Singapore. Interestingly, even within these countries, most of the hosts that observed blocking belonged to a few large ISPs.
Both in the U.S. and in Singapore, all hosts that suffered BitTorrent blocking are located in cable ISPs. We did not see any blocking of BitTorrent transfers from DSL hosts in these countries.
Most (573 of 599) U.S. hosts that observed blocking are located in Comcast and Cox networks. In Singapore, all blocked hosts are connected using the StarHub network. While we did observe blocking for hosts in 10 other ISPs (7 of which are in the U.S.), we did not see widespread blocking of BitTorrent traffic for hosts in those ISPs.