Comcast Tests User Throttling

Publicly pummeled over slowing BitTorrent traffic, the cable giant turns to blacklisting heavy users.

Comcast is testing a new method of managing network traffic that would target heavy users instead of the applications favored by bandwidth hogs. Comcast claims only a handful of users are clogging its broadband network and slowing it down for the vast majority of users.

In testing beginning in three markets June 6, Comcast plans to compile a blacklist of its heaviest users who may find their Internet speeds slowed during peak network hours, regardless of the software used to download files. Comcast insists most users will not be affected by the approach.

"When we roll this out nationally by the end of the year, all those types of questions will be answered," Comcast spokesman Charlie Douglas told The New York Times. "We are trying to figure out what do customers want, what techniques need to be in place to create the best user experience."

Comcast's first response to the problem was to throttle P2P applications such as BitTorrent during peak network hours. That approach, however, led to complaints, a lawsuit and a FCC (Federal Communications Commission) investigation that throttling is a violation of the FCC's network neutrality principles that prohibit the arbitrary blocking of applications.

The cable giant's subsequent public pummeling forced Comcast to come to an accord with BitTorrent and a promise to seek a more agnostic approach to network traffic management. The new testing is Comcast's first attempt to change its approach.

To Tier or Throttle

Comcast's solution is in sharp contrast with Time Warner Cable, which faces the same overburdened network problems. Time Warner is testing tiered service with monthly allowances for downloading and uploading files. Users exceeding their monthly allowance will pay $1 per gigabyte.

TW's tiers will begin at $30 a month for 768 kilobits per second service with a 5-gigabyte cap. The top tier goes for $55 a month for 15 megabits per second and a 40-gigabyte cap.

While the FCC has not completed its investigation of Comcast, Chairman Kevin Martin left little doubt of the ultimate outcome in testimony April 22 before the Senate Commerce Committee. Martin told lawmakers it appears Comcast broadband customers are not free to access all content on the Internet, including the ability to fully use peer-to-peer networks.

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."

Since the beginning of the controversy, Comcast has admitted throttling BitTorrent traffic but insisted its policy falls within the FCC's rules for reasonable network management practices. Comcast also said the practice was "imperceptible to the customer," a notion disputed by Martin.

"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 said in his testimony.

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."