Comcast vs. Net Neutrality?

I read in the news that Comcast is blocking some internet traffic in what has been called "traffic shaping".

NEW YORK - Comcast Corp. actively interferes with attempts by some of its high-speed Internet subscribers to share files online, a move that runs counter to the tradition of treating all types of Net traffic equally.

The interference, which The Associated Press confirmed through nationwide tests, is the most drastic example yet of data discrimination by a U.S. Internet service provider. It involves company computers masquerading as those of its users.

If widely applied by other ISPs, the technology Comcast is using would be a crippling blow to the BitTorrent, eDonkey and Gnutella file-sharing networks. While these are mainly known as sources of copyright music, software and movies, BitTorrent in particular is emerging as a legitimate tool for quickly disseminating legal content.

The principle of equal treatment of traffic, called "Net Neutrality" by proponents, is not enshrined in law but supported by some regulations. Most of the debate around the issue has centered on tentative plans, now postponed, by large Internet carriers to offer preferential treatment of traffic from certain content providers for a fee.

Comcast's interference, on the other hand, appears to be an aggressive way of managing its network to keep file-sharing traffic from swallowing too much bandwidth and affecting the Internet speeds of other subscribers. [...]

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. [...]

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. [...]

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 manner similar to the method Comcast is using, said the cable company was probably acting within its legal rights.

"It's their network and they can do what they want," said Watson. "My concern is the precedent. In the past, when people got an ISP connection, they were getting a connection to the Internet. The only determination was price and bandwidth. Now they're going to have to make much more complicated decisions such as price, bandwidth, and what services I can get over the Internet." [...]--AP

Anywhoo, if you're interested in some specifics of what exactly Comcast is doing, and how, you can follow this link. Apparently, Comcast is using Sandvine traffic shaping hardware. Here's an excerpt from the link:

"The Sandvine application reads packets that are traversing the network boundary. If the application senses that outbound P2P traffic is higher than a threshold determined by Comcast, Sandvine begins to interrupt P2P protocol sequences that would initiate a new transfer from within the Comcast network to a peer outside of the Comcast network. The interruption is accomplished by sending a perfectly forged TCP packet (correct peer, port, and sequence numbering) with the RST (reset) flag set. This packet is obeyed by the network stack or operating system which drops the connection."