Admits to using TCP reset packets to "delay" P2P file uploads
Comcast’s critics aren’t backing down after the company defended its traffic management practices in an FCC filing this week by asserting that its tactics fall well within the bounds of reasonable network management practices.
Comcast’s critics aren’t backing down after the company defended its traffic management practices in a FCC filing last week by asserting that its tactics fall well within the bounds of reasonable network management practices.
Comcast has been under fire from advocacy groups such as the Electronic Frontier Foundation and the Free Press since last October when the Associated Press reported that the company was actively interfering with some of its customers’ ability to share files online.
Essentially, the AP has reported, Comcast has been employing technology that is activated when a user attempts to share a complete file with another user through peer-to-peer technology such as BitTorrent and Gnutella. As the user is uploading the file, Comcast sends a message to both the uploader and the downloader telling them that there has been an error within the network and that a new connection must be established. Because the message sent to users does not appear to be sent directly from Comcast, many critics have accused Comcast of sending forged or spoofed packets that they say are deceiving to consumers.
In Comcast’s filing with the FCC, which came a little more than a month after FCC Chairman Kevin Martin announced that the FCC would investigate complaints about Comcast’s P2P traffic-blocking, the company came out swinging against its critics by accusing them of using “extremist rhetoric” and “inflammatory hyperbole” in their accusations. Comcast says that it only interferes with P2P traffic when such traffic is at a high enough level to “degrade the activities” for all of its high-speed Internet customers.
Comcast acknowledges in its filing that it sends out TCP reset packets to delay or stop P2P uploads. The company vehemently denies, however, that these TCP RST packets are “forged” and insists that they are only used “to signal that there is an error condition” on the network.
“This action is nothing more than the system saying that it cannot, at that moment, process additional high-resource demands without becoming overwhelmed,” writes Comcast, which compares its methods with those of “a traffic ramp control light [that] regulates the entry of additional vehicles onto a freeway during rush hour.”
Comcast’s critics, however, take issue with how the company characterizes its methods. For instance, when the EFF first tested Comcast’s network for TCP RST packet use, it noted that such that such packets were not present in similar tests it conducted on connections provided by AT&T, Sonic or overseas ISPs. As the EFF noted at the time, several other ISPs have to deal with users that hog bandwidth on their networks, and many of them use tactics such as dynamic per-user traffic shaping that mitigate individual user’s impact on their network by setting limits on how much data-per-second any user can transmit.
Additionally, the EFF says that it found no evidence in its tests to show that Comcast only targeted its jamming efforts at excessive bandwidth consumers, and that Comcast has sent TCP RST packets for BitTorrent file uploads that ranged from 500KB to 500MB. Finally, the EFF says that Comcast’s claim to use TCP RST packets only to delay the transfers of files over P2P networks is misleading because “at a low level, the forged RST packets cause the targeted TCP connections to die as soon as computers try to establish them.”
Seth Schoen, the EFF’s staff technologist, says Comcast’s decision to employ TCP RST packets to manage heavy traffic is puzzling because it has created such a public backlash against the company.
“Comcast has been subject to class-action litigation, an FCC complaint, and lots of public criticism for doing this,” he says. “It’s also clear that some portion of its users are angry about the fact that this is happening, or about the way Comcast misled them about the source of the problem when they tried to ask tech support what was wrong.”
The Free Press has been similarly unbowed in its criticism of Comcast. In comments filed with the FCC this week, the advocacy group accused Comcast of blocking traffic from BitTorrent and Gnutella to bolster their own online offerings, such as Fancast. The Free Press also shared the EFF’s view that Comcast’s claims to be merely “delaying” P2P file transfers to be misleading and accused the company of employing “anti-competitive tactics to maintain market advantage.”
“Comcast is making a desperate attempt to spin its Internet blocking,” says Marvin Ammori, general counsel for the Free Press. “Cut through all the jargon, and this much is clear: Comcast isn’t managing bandwidth hogs, it’s undercutting competition.”
The FCC officially began investigating the Comcast controversy last month when the Wireline Competition Bureau announced that it was seeking public comment on a Free Press petition that claimed Comcast’s P2P blocking violated the FCC’s Internet Policy Statement. The deadline for filing comments with the bureau is February 28.
