Comcast Blocks Some Internet Traffic

Former Vice President Al Gore smiles after speaking at a news conference in Palo Alto, Calif., Friday, Oct. 12, 2007. Gore and the United Nations Intergovernmental Panel on Climate Change were co-awarded the 2007 Nobel Peace Prize for spreading awareness of man-made climate change and laying the foundations for counteracting it. (AP Photo/Jeff Chiu) (Jeff Chiu - AP)

"There's the wrong way of going about that and the right way," said Elvey, who is a computer consultant.

Comcast's interference affects all types of content, meaning that, for instance, an independent movie producer who wanted to distribute his work using BitTorrent and his Comcast connection could find that difficult or impossible _ as would someone pirating music.

Internet service providers have long complained about the vast amounts of traffic generated by a small number of subscribers who are avid users of file-sharing programs. Peer-to-peer applications account for between 50 percent and 90 percent of overall Internet traffic, according to a survey this year by ipoque GmbH, a German vendor of traffic-management equipment.

"We have a responsibility to manage our network to ensure all our customers have the best broadband experience possible," Douglas said. "This means we use the latest technologies to manage our network to provide a quality experience for all Comcast subscribers."

The practice of managing the flow of Internet data is known as "traffic shaping," and is already widespread among Internet service providers. It usually involves slowing down some forms of traffic, like file-sharing, while giving others priority. Other ISPs have attempted to block some file-sharing application by so-called "port filtering," but that method is easily circumvented and now largely ineffective.

Comcast's approach to traffic shaping is different because of the drastic effect it has on one type of traffic _ in some cases blocking it rather than slowing it down _ and the method used, which is difficult to circumvent and involves the company falsifying network traffic.

The "Net Neutrality" debate erupted in 2005, when AT&T Inc. suggested it would like to charge some Web companies more for preferential treatment of their traffic. Consumer advocates and Web heavyweights like Google Inc. and Amazon Inc. cried foul, saying it's a bedrock principle of the Internet that all traffic be treated equally.

To get its acquisition of BellSouth Corp. approved by the Federal Communications Commission, AT&T agreed in late 2006 not to implement such plans or prioritize traffic based on its origin for two and a half years. However, it did not make any commitments not to prioritize traffic based on its type, which is what Comcast is doing.

The FCC's stance on traffic shaping is not clear. A 2005 policy statement says that "consumers are entitled to run applications and services of their choice," but that principle is "subject to reasonable network management." Spokeswoman Mary Diamond would not elaborate.

Free Press, a Washington-based public interest group that advocates Net Neutrality, opposes the kind of filtering applied by Comcast.

"We don't believe that any Internet provider should be able to discriminate, block or impair their consumers' ability to send or receive legal content over the Internet," said Free Press spokeswoman Jen Howard.

Paul "Tony" Watson, a network security engineer at Google Inc. who has previously studied ways hackers could disrupt Internet traffic in a manner similar to the method Comcast is using, said the cable company was probably acting within its legal rights.