One of the nation's largest telecommunications companies is using a controversial technique to cripple certain kinds of Internet traffic traveling across its networks, says a new report from the digital rigthts group the Electronic Frontier Foundation in San Francisco.

"Comcast is essentially deploying against their own customers techniques more typically used by malicious hackers (this is doubtless how Comcast would characterize other parties that forged traffic to make it appear that it came from Comcast or its subscribers,)" write the authors of the new report. "In other words, Comcast is essentially behaving like a telephone operator that interrupts a phone conversation, impersonating the voice of one party to tell the other that this call is over, I'm hanging up."

The nine-page investigation was conducted by EFF staff technologists Peter Eckersley, Seth Schoen and senior intellectual property attorney Fred von Lohmann.

The investigators say that their tests confirmed an earlier one conducted by the Associated Press that showed that Comcast is interfering with BitTorrent traffic. BitTorrent is a protocol used to efficiently distribute the online transmission of large files, and some entertainment companies have partnered with its creators to distribute its content online.

Comcast has said that it doesn't block BitTorrent, or any kind of content.

When asked about the new report, spokesman Charlie Douglas said that the company had no comment. And he directed Wired News to a past statement issued by the company that said that the company merely delays certain kinds of peer-to-peer traffic at peak congested times, rather than blocking it.

But the investigators' report says that it is Comcast's approach to managing the traffic that is most problematic.

The authors say that Comcast is forging Internet traffic and injecting it into its customers' file-sharing applications' stream of traffic to choke their transmissions.

The effect for the end user is that they may end up thinking that it is the software that they're using that's failing, note the report's authors.

Comcast does tell customers that it retains the right to manage the traffic to make sure that everything runs smoothly.

But the EFF's investigators note that Comcast's approach is discriminatory because it targets only certain kinds of applications – in this case, file-sharing applications. This kind of targeting undermines a fundamental ethos that has so far driven the success of innovators on the Internet – an open system that requires no permission from anyone to experiment online, they say.

"Comcast's recent moves threaten to create a situation in which innovators may need to obtain permission and assistance from an ISP in order to guarantee that their protocols will operate correctly," write the authors. "By arbitrarily using RST packets in a manner at odds with TCP/IP standards, Comcast threatens to Balkanize the open standards that are the foundation of the Internet."

The report may have far-reaching consequences since it presents detailed evidence of an ISP actively interfering with its customers' traffic in an apparently arbitrary fashion.

The report says, for example, that its tests showed "no evidence that Comcast was targeting their jamming efforts at customers based on their individual consumption of bandwidth," and that there are more above-board ways of managing their traffic.

Various parties may use the report to boost their cases both against Comcast, and to push forward new rules to ensure that telecommunications companies do not discriminate online.

Both the Bush administration and telecom companies have argued that there isn't any evidence of discriminatory actions to justify such rules.

Lawmakers have re-introduced legislation on the subject this year in the Senate, and a House bill sponsored by Massachusetts Democrat Ed Markey is expected to be dropped before the end of the year. In addition, a complaint against Comcast over the issue has been lodged at the FCC, and a California consumer has launched a lawsuit against the cable company in the wake of the AP story.

"Certainly the FCC ought to thoroughly investigate this, and based on that investigation take the appropriate steps," said Markham Erickson, executive director of the Open Internet Coalition. "It also argues for ex ante rules that prevents this from happening in the first place."

"In some ways, the EFF's paper raises an additional set of questions – they only looked at Comcast

\— what about the other ISPs, ... what other communications are being blocked and dropped?" he asked.

Comcast has 12.4 million high-speed Internet subscribers.

Addendum: The EFF has released an accompanying white paper that provides instructions on how to detect spoofing by your ISP. I'd be interested in chatting with anyone who tries this out with some friends.

See Also: