Comcast and Cox Communications are blocking BitTorrent traffic throughout all hours of the day, according to a report by Germany's Max Planck Institute. The global study released May 15 found widespread blocking of BitTorrent transfers only in the United States and Singapore.
The study further found that the blocking was occurring only among cable companies, and among those, the blocking was limited to a handful of large cable broadband providers. Comcast is the nation's second-largest broadband provider with 14.1 million subscribers, while Cox is the country's fourth-largest provider with 3.8 million users.
"Most (573 of 599) U.S. hosts that observed blocking are located in Comcast and Cox networks," the study concludes. "In Singapore, all blocked hosts are connected using the StarHub network. While we did observe blocking for hosts in 10 other ISPs (7 of which are in the U.S.), we did not see widespread blocking of BitTorrent traffic for hosts in those ISPs."
Comcast is already facing accusations of throttling BitTorrent traffic following reports last year by the Associated Press and the Electronic Frontier Foundation. The reports prompted an ongoing FCC (Federal Communications Commission) investigation for possible network neutrality violations by Comcast.
Comcast has admitted to the throttling but claims it occurs only during peak network hours and that it is "imperceptible to the customer." The cable giant claims its throttling practices fall within the FCC's reasonable network management exception to network neutrality rules, which prohibits discriminating against specific applications in handling network traffic.
"We analyzed our data to see if hosts in Comcast and Cox networks see fewer of their upstream transfers blocked during early morning or weekends (when network load is generally low) than during other times of the day," states the Planck report. "The percentage of blocked connections remains high at all times of the day. Our data suggests that the BitTorrent blocking is independent of the time of the day."
A Comcast spokesman rejected the Planck study, noting that P2P traffic can clog a network at any time of the day, necessitating reasonable network measures. Comcast also rolled its standard statement: ""Comcast does not, has not and will not block any Web sites or online applications, including peer-to-peer services like BitTorrent. We have acknowledged that we manage peer-to-peer traffic in a limited manner to minimize network congestion."
In addition, Comcast has committed to a protocol-agnostic network management technique no later than the end of this year. Cox Communications was unavailable for comment.
Providers Accused of Hiding Behind Network Management
"Consumers have no reason left to trust their cable company. This independent study confirms that Comcast is still blocking its customers from using popular applications - despite the FCC's investigation and widespread public outrage," Ben Scott, policy director of Free Press, said in a statement. "And worse, the harmful practice appears to be spreading through the marketplace."
Public Knowledge President Gigi Sohn added in a statement, "This study is further proof that the largest cable companies are hiding behind 'network management' excuses when caught throttling the legitimate traffic of their customers."
The FCC investigation has included public hearings in Boston and San Francisco. Last month, FCC Chairman Kevin Martin told a U.S. Senate panel that Comcast is throttling more traffic than it has previously admitted. "It does not appear that this technique [throttling] was used only to occasionally delay traffic at particular nodes suffering from network congestion at that time," Martin told lawmakers.
According to Martin, the testimony so far presented to the FCC indicates Comcast's efforts at managing P2P traffic "is typically deployed over a wider geographic or system area and would therefore have impacted nodes within a system simultaneously."
Comcast's technology, Martin added, "blocks the uploads of at least a large portion of subscribers in that part of the network, regardless of the actual levels of congestion at that particular time."