Mobile providers have been intentionally slowing down the data coming to your phone depending on what it is, and a study from Northwestern shows exactly how the practice works, and what data is being affected.
The process, as the paper explains, can be described as ‘differentiation,’ when service providers treat different kinds of traffic with inconsistent rules by throttling—artificially slowing—some forms of data but not others. You’ve been on the receiving end of throttling if you’ve ever blown through the data cap on your monthly plan and saw your speeds slow to a crawl across the board. Differentiation, though, is when one type of network traffic is throttled more than another and, according to a press statement from, assistant professor of computer and information science at Northeastern, is “what most people would refer to as a net neutrality violation.”
This sort of behavior has been undertaken by wireless providers for years prior to net neutrality’s official repeal partly thanks to a handy net neutrality loophole where they can claim that some apps and services (often those run by the provider itself) are exempt from the rules that otherwise govern your mobile plan. The official repeal of net neutrality, meanwhile, is blowing on this ember to turn it into a blaze.
Choffnes and two Northwestern students have been studying net neutrality since 2015, when the Federal Communications Commission (FCC) placed broadband providers under the same regulations that governed traditional telephone networks. The FCC also implemented strict “no throttling” rules. Choffnes built an app called Wehe to study the implementation and track when ISP were violating the rules.
“Reasonable network management practices are an important part of the internet,” said Choffnes at the time. “But innovation could be stifled if ISPs don’t give every application fair access to their network resources.”
The 2015 ruling would not last. In 2017, the FCC voted to repeal these net neutrality polices and the repeal went into effect earlier this year. During that time period and beyond, the Wehe app has been able to gather an ample amount of data. While the study will be fully released in 2019, enough is available now to show that throttling and differentiation are common practices among ISPs.
Studying over half a million data traffic tests across 161 countries, Choffnes found that ISPs are “giving a fixed amount of bandwidth—typically something in the range of one and a half megabits per second to four megabits per second—to video traffic, but they don’t impose these limits on other network traffic.”
Data throttling can serve a needed purpose. At times when ISPs are overloaded, like during a natural disaster, some throttling might be necessary in order to allow everyone access to the Internet. But no evidence that this was the rationale was observed during the study, undertaken by Choffnes with help from a team at the University of Massachusetts Amherst.
“There’s no evidence that any of these policies are only happening during network overload,” he says. “They’re throttling video traffic even when the network doesn’t need to. It happens 24/7, and in every region where we have tests.”
So why throttle if the network isn’t catastrophically overloaded? For one, it helps ISPs to delay the need to upgrade their infrastructure. Throttling can make a network that would be overloaded without throttling appear to be perfectly adequate due to throttling. It can also be used to drive users towards certain services, typically ones that the throttler stands to profit from in one way or another.
Choffnes has a laundry list of recommendations to improve the current situation: legislation to make net neutrality rules permanent, data throttling on the basis of need only, improved user awareness of how their ISP throttles and uses differentiation.
“This isn’t really about winners or losers,” he says. “If the network has enough resources to meet demand, everybody gets what they want.”