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Torrent to a Trickle

If you suspect that your ISP is blocking your BitTorrent traffic, call your ISP and ask whether you're being blocked. But don't trust that you'll get a straight answer.

A Road Runner customer and BitTorrent user from Bar Harbor, Maine is a good example. This user (who asked that his name not be used for fear that his ISP would treat him unfairly) called Road Runner's tech support when his BitTorrent download speeds dropped to a sluggish 8 kilobits per second. When he asked what was going on, a support rep reprimanded him for using BitTorrent software and accused him of downloading copyright-protected music. At the same time, the tech said he couldn't comment on bandwidth management issues.

"I was baffled by the entire exchange," the Road Runner customer said, noting that he was not trying to download copyright-protected content. "I pay a monthly fee for Internet access. I shouldn't be limited to watching YouTube videos, browsing the Web, and checking my e-mail."  (Road Runner's parent company, Time Warner Cable, says that it does not block peer-to-peer traffic to BitTorrent, but that it does manage its network in ways that would keep BitTorrent traffic in check.)

If your ISP's support reps won't tell you what's going on, look at the company's terms-of-service agreement (most are available online). Here again, though, you may find the answer unsatisfactory. Some ISPs couch their bandwidth management practices in vague policy statements that are difficult to decipher. Others such as Verizon and DSL Extreme are unambiguous: They don't mess with BitTorrent traffic.

If your ISP won't come clean about its BitTorrent bandwidth policy, you can try any of a handful of ways to test whether your BitTorrent traffic is being throttled.

One method is to test your own connection speed. BitTorrent download speeds for popular files with many sources should be in the same ballpark as your bandwidth speeds in benchmark test results.

A popular Web-based tool, Glasnost, claims to be able to check whether your ISP is meddling with your BitTorrent traffic. The tool, created by the Max Planck Institute for Software Systems, requires no download; performing the test takes about 4 to 7 minutes.

For diehard techies who are willing to tinker, the Electronic Frontier Foundation developed a tool called Pcapdiff that tests whether your ISP is disrupting BitTorrent traffic.

Last, the makers of the BitTorrent client Vuze have created a plug-in for their peer-to-peer file swapping client. Downloading and running it on your PC won't help you determine whether your ISP is meddling with BitTorrent traffic--but it will help Vuze, which uses the data to lobby the FCC to prohibit limitations on BitTorrent.