Editor’s Note: The following article is reprinted from Network World.
Comcast announced this week that it will no longer target individual protocols for traffic shaping, and will instead slow Web traffic for individual users who consume a “disproportionate” amount of bandwidth.
The new methods mark a shift in Comcast’s traffic-management policies, which had previously targeted peer-to-peer protocols such as BitTorrent and eDonkey for traffic shaping. Essentially, anytime a Comcast customer would try to upload a large file through a P2P protocol, Comcast would send TCP RST packets to both the file’s uploader and the downloader telling them that there was an error within the network and that a new connection would have to be established.
Now Comcast says it will instead target individuals who consume large amounts of bandwidth by “de-prioritizing their data usage” in order to free up bandwidth for others on the network. Practically speaking, this means that a heavy-bandwidth consumer will still be able to use any applications they want, but that their traffic will be slowed in order to make the network faster for others. Additionally, the company says it will only use these traffic-shaping methods during times of network congestion, and heavy-bandwidth users will be able to use their P2P protocols at regular speeds during non-peak hours.
Comcast says it will begin testing its new traffic management methods this summer in Chambersburg, Pa., Warrenton, Va., and Colorado Springs, Colo., with the goal of rolling out the new management practice nationwide by year-end.
Advocacy groups, such as the Electronic Frontier Foundation and Free Press, have been pressuring Comcast to change its traffic management practices since October, when the Associated Press first reported that the company was actively interfering with some of its customers’ ability to share files online. Specifically, the groups say Comcast is deceiving its customers when it sends them TCP RST packets that do not appear to be sent directly from the company, and the company should not be allowed to pick and choose which applications it allows or blocks. Comcast, however, says it doesn’t actively block any P2P protocol, and it merely “delays” P2P uploads during times of heavy congestion.
The company was also sharply criticized last February by several panelists at a FCC hearing on broadband network management practices. In particular, panelist Marvin Ammori, the general counsel for the Free Press, accused Comcast of engaging in anticompetitive behavior, noting that applications such as BitTorrent can be used to deliver on-demand movies that Comcast charges customers for in its cable services. One month after the FCC hearing, Comcast announced that it had agreed to stop targeting individual P2P protocols in its traffic-shaping policies.
A recent study by the Max Planck Institute for Software Systems showed that P2P traffic throttling was prevalent among cable company ISPs such as Comcast and Cox, and that all of the study’s U.S.-based hosts that found their P2P traffic blocked were located on cable networks.