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Elude Your ISP's BitTorrent Blockade

I'm a fan of live music and a patron of online communities such as, where music junkies swap copyright-free music. So I was stung when I recently tried to download a live recording of a Dave Matthews concert only to discover that my BitTorrent client was dead in the water.

My system and Net connection checked out fine, so paranoia immediately set in: Was my Internet service provider, RCN, blocking BitTorrent? I called RCN and the tech I spoke to confirmed my suspicions, telling me that the ISP had added BitTorrent to its list of prohibited programs because many people use the software to download copyrighted material. The fact that the concert I was trying to download was copyright-free didn't sway him.

Later I called RCN's press department as a reporter, and the story changed. The ISP's spokesperson told me that the customer support rep I had talked to earlier misspoke. RCN has never intentionally blocked peer-to-peer traffic, the spokesperson said, and it supports the principles behind Net neutrality. Within 24 hours, my bandwidth-related problems with BitTorrent vanished.

Of course, most people can't call their ISP and (honestly) identify themselves as professional journalists. But that doesn't mean you have no recourse if your ISP starts blocking your file-sharing activities. A number of tips and tools can help you determine whether you're facing a BitTorrent blockade and, if so, help you get around it.

Vuze, a company that makes peer-to-peer software and uses the platform to distribute content, published a study in April in which it concluded that all U.S. broadband providers--including AT&T, Cablevision Systems, Charter Communications, Comcast, Cox Communications, Qwest, Time Warner Cable, and Verizon--disrupt peer-to-peer traffic. Vuze asserted that these ISPs regularly send "false reset" messages to the Vuze software with the aim of slowing file transfers.   

AT&T has flatly denied this claim. Subsequently, Vuze has softened its charge against ISPs, stating that "Our data collection was credible and transparent, but not conclusive," in the words of Jay Monahan, Vuze general counsel.

Other ISPs have acknowledged imposing some limitations on peer-to-peer traffic. Comcast first denied but now admits to interrupting access to file-sharing programs such as BitTorrent. Comcast executive vVice president David L. Cohen explained at a Federal Communications Commission hearing last February that disrupting BitTorrent traffic was a reasonable method of traffic management during busy usage periods.

Time Warner Cable spokesperson Alex Dudley says that his company takes reasonable steps to manage its network, including limiting bandwidth to applications such as peer-to-peer software.

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.

The Glasnost utility tests whether your ISP is interfering with your use of BitTorrent content, and reports its findings to you.
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.

Evasion of the Bit Snatchers

If you discover or strongly suspect that your ISP is slowing your BitTorrent traffic, you can try several countermeasures, none of them a sure bet.  One of these techniques may work for one ISP but not for another.

First, try using encryption to cloak your peer-to-peer traffic. Most clients such as BitComet, BitTorrent, uTorrent, and Vuze, support in-client encryption. Turning this feature on makes it much harder, though not impossible, for your ISP to detect that you're using peer-to-peer software. Here's how to proceed.

BitComet: Go to the Options menu, choose Preferences, Advanced, Connection, and select Protocol encryption.

BitTorrent and uTorrent: Go to the Preferences panel and select the BitTorrent tab. Choose Protocol encryption and select enabled.

Vuze: First you must change your user profile from the default beginner mode to advanced. Go to the Tools drop-down menu, open the Configuration Wizard, and select advanced. Next return to the Tools drop down menu and select Options, Connection, Transport Encryption. Check Require encrypted transport, go to the Minimum encryption drop-down menu, and select RC4 encryption.

A second method of evading an ISP's throttling practices is to change the way the BitTorrent protocol acts. This method may work against ISPs that try to throttle speeds based on a standard set of BitTorrent configurations.

Troubleshooting your BitTorrent client's protocol settings can be tricky. To reconfigure your software, refer to the instructions provided by the publisher of the BitTorrent client you're using. One simple yet effective way to experiment with alternate BitTorrent protocol configurations is to simply try a different BitTorrent client. Different clients use different default protocols, and one may perform better on your ISP's network. 

The default communications port used by BitTorrent traffic is 6881. ISPs know this and watch that port like a hawk. If an ISP throttles or blocks BitTorrent traffic traveling through this port, your file-sharing speeds will plummet. 

To elude ISP throttling, BitTorrent clients enable you to switch the port or port range that your computer uses for BitTorrent traffic. Some BitTorrent clients will automatically attempt to configure your firewall or router to allow traffic to pass through the new port; with others you may have to open ports on your router manually. The excellent Port Forward site will step you through the process of tweaking your router to permit incoming connections.

One more-advanced method of obfuscating your BitTorrent traffic involves using an encrypted tunnel that, as the name suggests, shields from your ISP the type of data you are sending and receiving.

Free services such as The Onion Router (TOR) and I2P are designed for sending anonymous and encrypted messages, but some people have adapted them to use BitTorrent connections. The Vuze client has built-in support for routing your traffic through TOR and I2P.

For about $5 a month, commercial virtual private network providers such as Relakks and SecureIX can help you prevent your ISP from identifying BitTorrent traffic. In marketing its service, SecureIX promises that it will "disable P2P throttling." The company offers a free tier of service with a bandwidth limit set to 256 kbps.

But ISPs are catching on to these advanced encryption techniques, reportedly clamping down and throttling encrypted tunnels despite being unsure that the encrypted data is BitTorrent traffic. The most extreme method an ISP may use to manage peer-to-peer traffic is to block anything that appears to be BitTorrent traffic, encrypted or not. If that happens to you, you must either switch ISPs or stop using BitTorrent software.

Future Mixed for File Sharers

If you hope that the federal government will enshrine a "right to download" any time soon, you're likely to be disappointed. Nevertheless, technical changes are in the works that could make using peer-to-peer apps easier, albeit more expensive.

Groups such as the Electronic Frontier Foundation and Vuze, a peer-to-peer software company, have asked the Federal Communications Commission to force ISPs to disclose any discriminatory network management practices they engage in. But the FCC has stated that it probably won't adopt any new regulations forcing ISPs to disclose or desist from any slowing practices, because it feels current laws are strong enough. Though the FCC has criticized Comcast for slowing peer-to-peer traffic, FCC chairman Kevin Martin seems most irked by the fact that Comcast and other ISPs aren't up-front about how, when, and whether they do it.

A new, advanced peer-to-peer technology known as P4P could help both ISPs and file swappers. Verizon and Comcast have expressed interest in Proactive Network Provider Participation, which reportedly can boost the delivery speeds of file transfers using the BitTorrent protocol by as much as 600 percent while simultaneously making it easier for ISPs to manage their bandwidth. Verizon ran tests using P4P earlier this year, and Comcast says that it will test the technology on its network in June. As yet, no ISP has announced that it will use P4P on its networks.

According to Pando Networks, which has tested P4P technology and is a member of the P4P Working group, the protocol permits smarter routing of peer-to-peer traffic by sending requests for a specific file within an ISP's own network first, before connecting to another ISP's network. This approach reduces bandwidth costs incurred by ISPs for connecting to a third-party network, and it allows ISPs to manage their bandwidth more efficiently. Essentially, the closer a file is, the less bandwidth the ISP needs to expend in downloading it.

There may be a catch, however. Since ISPs will ultimately be the ones to deploy P4P technology, they will decide which applications can use the technology. If an ISP believes that an app is generally used for illegal downloads, it may block its connection to the P4P network. At the same time, Comcast is pledging to become "protocol agnostic" by the end of 2008. According to Comcast's Sena Fitzmaurice, senior director of corporate communication and government affairs, being "protocol agnostic" is not quite the same as embracing Net neutrality. Rather, being "protocol agnostic" is a pledge to treat all protocols the same. Comcast could still slow BitTorrent traffic, but it would have to treat other traffic, such as bandwidth dedicated to YouTube videos, equally.

The change may still leave heavy file sharers singing the blues. According to Fitzmaurice, being "protocol agnostic" means that ISPs would stop managing specific types of traffic and instead would begin managing individual users. So people who download five high-def movies a day using BitTorrent (or a download service such as iTunes) are likely to be singled out as bandwidth hogs and "managed"--perhaps by having their Internet speeds slowed during times of heavy demand. Light users of BitTorrent, meanwhile, would see relatively speedy downloads.

It's too early to say what Comcast's usage limits might be, Fitzmaurice says. Industry experts anticipate that Comcast and any other ISP that adopts the protocol-agnostic pledge may impose monthly bandwidth consumption caps on users. Terms-of-service agreements would outline enforcement policies, which might include paying a penalty if you download or upload too much content. Time Warner Cable is currently testing a service plan that enforces overage charges in Texas. In Canada, bandwidth caps are a fact of life for many broadband customers.

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