February 12, 2009

More HSD: Cox Explains Network Trial

By Jonathan Tombes

Cox Communications’ high speed data network congestion trial began this week in Kansas and Arkansas. But the trial itself has been on trial since being announced three weeks ago.

The battle lines formed quickly. In a January 28 post on DSL Reports, Karl Bode at DSL Reports leaned on comments from the FreePress, a group that advocates the reform of big media, and the engineer who discovered network-throttling efforts at Cox and Comcast in late 2007.

Meanwhile, Scott Cleland at the Precursor Group blasted a story by AP reporter Peter Svesson for jumping to the conclusion that Cox was violating principles of net neutrality.

And that was just the start of it.

Now that the network trial has actually begun, Cox has begun a quiet counteroffensive, "the first wave of pulling the curtain back … (on a) new approach to congestion management," said Cox Director of Media Relations David Grabert.

In an interview with CT, Cox SVP Technology Jay Rolls said congestion was a "corner case," i.e., the kind of problem that occurs outside normal operation parameters. "Most of the network is humming away."

When congestion does occur, Rolls said that the new approach being trialed is to put the traffic into two buckets, the time-sensitive and non-time sensitive. The former service flows being "noticeable to the customer when they start to delay."

"Those services we’d like to leave alone," Rolls said.

In the event of congestion, data network equipment treats the non-time sensitive services differently. "We slow that traffic down in order to relive congestion," Rolls said. "We’re talking on a per-packet basis, seconds or sub-seconds."

That kind of delay on time-sensitive flows, such as voice over IP, could be devastating. While packet aware, the technique does not label all peer-to-peer applications as eligible for delay.

"There are plenty of streaming video services that are served by a peer-to-peer application," Rolls said. "Those will be deemed time-sensitive and will be advantaged by this scheme."

The trial concerns upstream traffic only, using packet inspection technology on a per upstream CMTS port basis. It covers hundreds of neighborhoods in Cox’s Kansas and Arkansas serving area, which is managed out of Wichita.

The Cox approach differs from Comcast, which is trialing a scheme that downgrades individual heavy users on a congested CMTS port from priority best-effort (PBE) to best-effort (BE) status. Comcast instituted its "transparent" method last fall after the FCC ruled in August 2008 that the MSO was unreasonably restricting Internet users.

How the Cox outreach to interested parties fares remains to be seen.

Network neutrality absolutists believe that all packets are created equal and regard distinguishing one from another as invidious discrimination.

Other points raised in online discussion of Cox data network policies include the claim that Cox has signed an agreement with the recording industry regarding enforcement of the Digital Millenium Copyright Act of 1988 ("We have not," said Grabert) and the question of whether Cox is using this congestion technique as a way to delay rolling out DOCSIS 3.0 ("We're close to launching," said Rolls.)

Rolls hopes to begin seeing data from the trial within "a week or two."

- Jonathan Tombes

Read more news and analysis on Communications Technology's Web site at www.cable360.net/ct/news/.