Comcast, the US second-largest Internet provider, told the FCC in formal comments that its policy to block its users from some file-sharing traffic was a justifiable method to keep the traffic flowing and to ensure the same level of online experience to all users.

A "very small number of broadband users employ certain (peer-to-peer) protocols that utilize immense amounts of bandwidth in ways that are unpredictable and inconsistent and that can threaten to overwhelm network capacity and harm the online experience of other users," Comcast said in the filing. "That is why, even with continuous upgrades and constant investment, the fact remains that network capacity is not - and never will be - unlimited."

Comcast’s defense is just the latest development in a controversy that started last year when the Associated Press has found that Comcast appears to interfere with the BitTorrent traffic in ways which pose ethics questions. Specifically, instead of throttling BitTorrent traffic, the company appears to create spoof peers that interfere with the normal peer-to-peer transfers and significantly slow down or even kill some downloads. Furthermore, their test has shown that Comcast appears to "impersonate" existing peers to divert packets.

In November, the SaveTheInternet.com web site and some Internet scholars from Harvard, Yale and Stanford have filed a complaint to the Federal Communications Commission asking it to check on and clarify Comcast’s bandwidth policy. These people have also asked the Federal Communications Commission to prevent all the Internet service providers from degrading the file-sharing applications in the future.

In the filing, Comcast also revealed some of its network management practices. “Comcast's network management practices

(1) only affect the protocols that have a demonstrated history of generating excessive burdens on the network;
(2) only manage those protocols during periods of heavy network traffic;
(3) only manage uploads;
(4) only manage uploads when the customer is not simultaneously downloading (i.e., when the customer's computer is most likely unattended) ("unidirectional sessions" or "unidirectional uploads"); and
(5) only delay those protocols until such time as usage drops below an established threshold of simultaneous unidirectional sessions”, said the company in its filling to the FCC.

Meanwhile, Reps. Ed Markey (D-Mass.), chairman of the House Energy and Commerce Committee's subcommittee on telecommunications and the Internet, and Chip Pickering (R-Miss.) proposed today a bill to promote the principle, known as "Net neutrality," of treating all Internet traffic equally.

The “Internet Freedom Preservation Act of 2008” (HR 5353) protects Net Neutrality under the Communications Act and calls for a nationwide conversation to set policy about the future of the Internet.

The new bill requires the FCC to actively protect the free-flowing Internet from gatekeepers, enforcing protections that “guard against unreasonable discriminatory favoritism for, or degradation of, content by network operators based upon its source, ownership, or destination on the Internet.”

"Our goal is to ensure that the next generation of Internet innovators will have the same opportunity, the same unfettered access to Internet content, services and applications that fostered the developers of Yahoo, Netscape and Google," Markey said in a statement.