Comcast has disabled a throttling system that it deployed in 2008 in order to slow down heavy Internet users.

Comcast's network is now strong enough that a congestion management system isn't needed, the company says. The system has been "essentially inactive for more than a year," and is now disabled entirely.

Yet the nation's largest cable operator still imposes data caps and overage fees in 27 states, claiming that it limits the amount of data customers use each month "based on a principle of fairness."

Comcast initially deployed its congestion management system after it was caught throttling BitTorrent traffic over a decade ago. The system deployed in 2008 was application-agnostic. Instead of targeting specific online services, Comcast used the system to slow down heavy Internet users regardless of which applications they were using.

News of Comcast disabling the 10-year-old congestion management system came in a company announcement Monday:

As reflected in a June 11, 2018 update to our Xfinity Internet Broadband Disclosures, the congestion management system that was initially deployed in 2008 has been deactivated. As our network technologies and usage of the network continue to evolve, we reserve the right to implement a new congestion-management system if necessary in the performance of reasonable network management and in order to maintain a good broadband Internet access service experience for our customers and will provide updates here as well as other locations if a new system is implemented.

The broadband disclosure helps Comcast comply with the Federal Communications Commission's transparency rule, which the FCC updated at the same time that it eliminated net neutrality rules. "Comcast currently does not maintain a separate system to assist with managing times of congestion," the disclosure says.

No change in data cap policy

If Comcast's network can now handle all of its customers' bandwidth needs with room to spare, you might think the company would stop imposing data caps. But Comcast customers who exceed the 1TB monthly cap must pay another $10 for each additional 50GB, or an extra $50 every month for unlimited data. Comcast provides customers with no method of verifying whether its data usage meter is accurate, even though some customers have been wrongly charged overage fees.

We asked Comcast why it still imposes data caps now that it has no need for a congestion-management system and will update this story if we get an answer.

The company did offer this statement on why it shut down the congestion-management system:

Our network and consumer devices have evolved to a point that our old congestion-management system is no longer necessary. The system has been essentially inactive for more than a year. With well over 99 percent of our Internet customers using more modern DOCSIS gateways and modems, congestion on individual channels is no longer an issue that needs to be managed. We took the opportunity to formalize this change while we were updating our other customer disclosures.

Comcast has generally stopped short of claiming that data caps are needed for congestion management, but it has argued that overage fees are necessary to pay for network upgrades.

"Our network is not an infinite resource, and it is expensive to expand it," Comcast Executive VP David Cohen said in 2012 upon announcing the overage fees. "As a result, appropriate pricing has to take into account total cost of building, maintaining, and operating the network, not just incremental operating costs."

Comcast charges for speeds and usage

But even before implementing data caps and overage fees, Comcast already had a method for ensuring fairness in pricing. Comcast has long required heavy Internet users to pay more than light Internet users by charging higher prices for higher bit-rates.

This pricing scheme lets customers pay entry-level prices for basic service, while heavier cable users can use hundreds of megabits per second or even a gigabit if they pay for higher per-second bit-rates. But the addition of data caps forced heavy Internet users to pay for that extra bandwidth twice—a customer who actually uses all the bandwidth they pay for every second of every day would quickly surpass the monthly cap and be on the hook for extra payments. (Comcast's 2Gbps residential fiber service has no data cap; Comcast business customers don't face data caps, either.)

Data caps, combined with the death of net neutrality rules, could allow Comcast to start charging websites and online services for the right to deliver data that doesn't count against Comcast customers' data caps. The net neutrality rules didn't outlaw such zero-rating, but the FCC evaluated each zero-rating scheme to determine whether it harmed competitors or consumers. As the repeal is now final, the FCC will no longer try to limit the spread of zero-rating. Comcast could also zero-rate its own online video content, as it does with its Stream TV cable service.

“Protocol-agnostic” congestion management

After Comcast was caught throttling BitTorrent traffic in 2007, the FCC in 2008 ordered Comcast to stop discriminatory network management practices.

Although a court later overruled the FCC's action, the controversy led to a class-action settlement and changes in how Comcast managed its network.

Comcast informed the FCC in 2008 that its new approach "will be protocol-agnostic; that is, it will not manage congestion by focusing on the use of the specific protocols that place a disproportionate burden on network resources or any other protocols. Rather, the new approach will focus on managing the traffic of those individuals who are using the most bandwidth at times when network congestion threatens to degrade subscribers' broadband experience and who are contributing disproportionately to such congestion at those points in time."

Comcast noted that its cable system is "a shared network" and said that "the goal of Comcast's new congestion management practices will be to enable all users of our network resources to access a 'fair share' of that bandwidth, in the interest of ensuring a high-quality online experience for all of Comcast’s HSI [high-speed Internet] customers."

The system, according to Comcast, identified heavy Internet users and assigned them a "lower priority status" so that their traffic would be delayed during times of congestion. "The subscriber's traffic returns to normal priority status once his or her bandwidth usage drops below a set threshold over a particular time interval," Comcast told the FCC.

Comcast provides a further description of the system at this webpage:

This technique will identify which customer accounts are using the greatest amounts of bandwidth, and their Internet traffic will be temporarily managed until the congestion period passes. Customers will still be able to do anything they want online, but they could experience longer times to download or upload files or slower Web surfing. Our technique does not manage congestion based on specific online activities, protocols, or applications that a customer uses. Rather, it only focuses on the heaviest users in real time, so that congestion periods tend to be fleeting and sporadic. It is important to note that the effect of this technique is temporary and has nothing to do with a customer's aggregate monthly data usage. Rather, it's dynamic and based on prevailing network conditions as well as a customer's data usage over a very recent period of time.

Comcast hired network management system vendor Sandvine to help implement its then-new approach.

If Comcast does bring back a congestion-management system, the death of net neutrality rules could allow the company to be more aggressive in targeting specific types of applications.

The FCC's net neutrality rules had an exception for "reasonable network management," allowing ISPs to fairly allocate resources without blocking or throttling all traffic from a particular application or type of application. With net neutrality rules now eliminated, Comcast and other ISPs may block or throttle any type of traffic as long as they publicly disclose the fact that they're doing so.

So far, Comcast and other ISPs are saying they'll abide by the general principles of net neutrality even though the rules have been eliminated. The FCC still has to defend its repeal in court, and Congress is considering whether to implement a new set of net neutrality rules. State governments are also taking action—the State of Washington on Monday became the first US state to impose a net neutrality law that replaces the nationwide regulations repealed by the FCC.