News

Slamming on Bit Brakes

4/26/2008 2:00 AM Eastern

Comcast hasn’t been alone in clamping down on bandwidth-sucking BitTorrent file-sharing applications.

The eight biggest Internet service providers in the United States — which collectively serve more than 54 million broadband users — all “artificially interrupt” peer-to-peer traffic to some extent, according to a study by P2P video distributor Vuze.

The study, released April 18, found that AT&T, Cablevision Systems, Charter Communications, Comcast, Cox Communications, Time Warner Cable, Qwest Communications International and Verizon Communications regularly send false commands, designed to slow down file transfers, to BitTorrent-based peer-to-peer software.

Operator Internet Network ID Unique Users Monitored Media Reset Rate*
* Ratio of P2P resets to total attempted network connections per segment.
SOURCE: Vuze
Comcast 33668 40 23.7%
Cablevision 6128 71 17.6%
AT&T (BellSouth) 6389 21 15.9%
Charter 20115 55 13.2%
Qwest 209 77 12.4%
Cox 22773 143 12.0%
Verizon 19262 216 11.9%
Time Warner Cable 11427 52 11.6%


FCC IS PROBING

Comcast has borne the brunt of attention on this issue, with the Federal Communications Commission currently investigating the operator for its practice of selectively blocking P2P transmissions that traverse its network.

FCC chairman Kevin Martin, in testimony before the Senate Commerce Committee last week, criticized Comcast for using “blunt means to reduce peer-to-peer traffic by blocking certain traffic completely” (see Rules, p. 22).

While Martin said the agency’s investigation into Comcast’s practices was not complete at this point, he suggested the FCC has the authority to take action against the company.

The regulator’s scrutiny could extend other operators, if officials pursue the allegations by Vuze that the practice of impeding P2P traffic is employed by every major provider.

“We believe that there is sufficient data to suggest that network management practices that 'throttle’ Internet traffic are widespread,” Vuze said in its report.

BitTorrent chief technology officer Eric Klinker corroborated the finding that virtually every large provider has been throttling back the P2P protocol used by BitTorrent applications, using equipment from Sandvine or other vendors.

“Comcast was just the most aggressive,” he said, noting that since the FCC initiated the probe of Comcast other ISPs have started putting more P2P-friendly policies in place.

Klinker and his team are now working with Comcast to move to a “protocol-agnostic” bandwidth management strategy that will throttle back the heaviest users of bandwidth, rather than targeting specific applications. BitTorrent is working with other cable operators and telcos, too, he added.

Now BitTorrent is attempting to sell a P2P service for content providers to less expensively distribute “legitimate” video — a service the company wants to ensure does not get blocked by Comcast or others.

The BitTorrent DNA service uses a 200-kilobyte piece of Web code to distribute progressively downloaded video files among users who opt in to watch it, for about half the cost of a traditional content-distribution network like Akamai Technologies, according to Klinker.

Klinker claimed BitTorrent’s test show DNA can offload at least 70% of the bandwidth needed to distribute video, even for short clips of less than 2 minutes.

Vuze is in some respects a BitTorrent competitor, although its software uses the openly available BitTorrent-developed P2P protocol.

Palo Alto, Calif.-based Vuze distributes promotional and ad-supported video files over the Internet from more than 100 content partners. Formerly known as Azureus, the company claims its application has been downloaded at least 20 million times. BitTorrent said Internet users have downloaded software that uses its protocol 170 million times.

1 MILLION HOURS

Vuze collected the data — representing more than 1 million hours of Internet connectivity — between Jan. 1 and April 13 from 8,000 users worldwide who voluntarily agreed to share the data for the purposes of analysis.

Between 10% and 24% of all P2P connection attempts on networks operated by the eight largest U.S. broadband providers were “reset,” causing the software to wait before attempting to initiate another connection, according to Vuze’s analysis of data generated from ISP network segments with at least 20 unique users.

“At a minimum, more investigation is required to determine whether these resets are happening in the ordinary course of business or whether they are the kind of throttling practices which target specific applications and/or protocols” to the detriment of P2P users, Vuze said.

In November, Vuze filed a petition with the FCC, urging the agency to implement rules that would prevent Comcast and other Internet service providers from “interfering” with P2P traffic.

In addition to the eight biggest U.S. providers, Vuze found that Canadian service providers Bell Canada, Rogers Cable Communications, Shaw Communications and Cogeco also disrupted P2P traffic, along with ISPs in Europe and elsewhere.

Vuze has raised $34 million in funding, from investors including New Enterprise Associates (NEA), Redpoint Ventures, Greycroft Partners, BV Capital and CNET chairman Jarl Mohn.

September