Study: Cox, Comcast Play Traffic Cop Day and Night

Cox Communications is actively blocking BitTorrent file-sharing users from enjoying unfettered Internet services, according to a new study based on more than 8,000 Internet users. Like Comcast (Nasdaq: CMCSK), which was the first major cable Internet service provider (ISP) to be outed for throttling peer-to-peer data, Cox says it interferes with the traffic to ensure quality service for all of its customers.

Comcast's Internet service tampering garnered the attention of federal regulators, and the resulting brouhaha over the company's so-called protocol filtering practices made Comcast a poster child for the need for Net neutrality legislation. Comcast, however, has expressed its intent to work with BitTorrent to address network management issues in a more customer-friendly way -- or at least, in a more open manner.

The whole notion of openness, it seems, appears to be one reason why Cox hasn't yet met with the same uproar over its network management practices.

It's In the User Policy

Robb Topolski, a Comcast customer who is also a networking and software testing analyst, has analyzed the interference and attributed it to Sandvine equipment being used on the Comcast network for session tampering. Sandvine is a maker of network management products. Topolski also detected Sandvine-like behavior on Cox a few months ago, he told the E-Commerce Times.

"Cox also quickly confirmed that the interference being seen on their network was intended and was part of their network management techniques. The lack of a cover-up kept Cox out of the spotlight with most, but their abusive interference with their customers communications is the same," Topolski explained.

Cox's user policies indicate that it will use network management techniques to ensure high-quality service, so from a Cox standpoint, what Topolski calls "abusive interference" is more akin to quality of service.

"Cox's network management practices ensure that bandwidth-intensive applications don't negatively impact our customers' Internet service," David Deliman, a spokesperson for Cox, told E-Commerce Times.

"Cox allows the use of file-sharing and peer-to-peer services for uploads and downloads, and we allow access to all legal content, but we must manage the traffic impact of peer-to-peer services, as most ISPs do for the benefit of the customer," he added. In 2007, Cox High Speed Internet was awarded PC Magazine's Readers' Choice Award for the fourth time in five years, he said, and the company continues to grow its subscriber base each year.

The Study

The Germany-based Max Planck Institute for Software Systems has published an extensive study, "Glasnost: Results from tests for BitTorrent traffic blocking," that it conducted from March 18 to May 15, 2008. Results uncovered what appears to be widespread BitTorrent blocking by three ISPs -- Comcast, Cox and StarHub, which is based in Singapore. While the study detected blocking in ten other ISPs (seven of which were in the U.S.), "widespread" BitTorrent blocking was not consistently found.

The most surprising finding in the study may be that Comcast and Cox are blocking BitTorrent purposely during all times of the day. "Recently it has been reported that Comcast defended its BitTorrent blocking before FCC as a necessary practice that is done only during periods of heavy network traffic," the study noted, explaining that network traffic congestion is usually predictable during each day.

"The percentage of blocked connections remains high at all times of the day. Our data suggests that the BitTorrent blocking is independent of the time of the day," the study reported.

The Nature of the Problem

Cable ISPs, Topolski said, are dividing a limited pool of upload bandwidth -- about 10 megabits per second (Mbps) -- with anywhere between 125 and 500 customers in a neighborhood. Consequently, when customers are hogging the bandwidth, it can affect others in the neighborhood.

"Earlier, they [cable ISPs] could control this by providing only 128 to 256 Kbps (kilobits per second) uplinks, but as competition with FiOS (fiber optics) heated up, they had to open customers' pipes more in order to keep them. Using the 'punchbowl party' analogy, we have the same sized punchbowl but the guests now have much bigger glasses to fill," he explained.

"The Internet has struggled with bandwidth issues throughout its entire lifetime. Moore's Law [i.e. faster processors] brought the advent of deep packet inspection hardware and the ability to forge packets on the fly," Topolski explained.

"This new technology is simply a solution looking for a problem but is in no way an appropriate solution for a problem as common and as well understood as users' increasing bandwidth demands on the Internet," he added.