US cable giant to throttle P2P

No, not that one

By Cade Metz in San Francisco • Get more from this author

Posted in Telecoms, 28th January 2009 23:05 GMT

Free webcast: Service level monitoring and management

The Comcast Analogy

Comcast - America's largest cableco - recently rolled out its own system for throttling certain network traffic during periods of congestion. But it works a bit differently.

Comcast's new software monitors traffic on each segment of its network, the company says, and if a segment's upstream or downstream usage exceeds certain thresholds, traffic from subscribers using particularly large amounts of bandwidth will be delayed.

Comcast settled on this so-called "protocol agnostic" approach after it was slapped by the FCC for surreptitiously blocking P2P traffic. The FCC insisted that the cableco adopt network-management techniques that don't discriminate against particular applications.

Cox is confident its methods will appease the FCC - even though its methods do seem to discriminate against particular applications. "If you're selecting applications and deciding which should be delayed and the user has no choice," Scott says, "that strikes me as problematic."

What's more, all signs indicate that the FCC will soon come down even harder on ISP management practices. An avowed net neut is set to take the Commission's reins now that Barack Obama is in the Oval Office.

Network architect Richard Bennett - one of Comcast's staunchest supporters during its battle with the FCC - takes the other side. "The issue for net neutrality as always been VOIP. Cox claims it is positively affecting VOIP, and they claim it will positively affect video streaming," he says, "and if that's the case, they're on the side of the user here."

But for many - including Peter Eckersley, staff technologist at the Electronic Frontier Foundation, another net watchdog - the problem is that Cox presumes to know what the user wants. "They are planning to detect different network protocols (or use-cases for those protocols), and have their own rules about how those protocols will be treated. If that's the case, Cox will be picking winners and losers, and leading us into a briar of thorny network neutrality questions.

"The problem is that there is no reliable and fair way for the network to decide which protocols should be prioritized. Cox says it wants to prioritize bandwidth-intensive streaming video, but deprioritize bandwidth-intensive P2P protocols like BitTorrent. How do they know that some program isn't using a P2P protocol to stream video in real time? People in fact do that all the time."

As the net neuts and the anti-net neuts fought like the Hatfields and the Coys over Comcast's BitTorrent blocking, independent tests also indicated that Cox was throttling P2P on the sly. But a formal complaint was never filed. ®