YouTube, Netflix Videos Found to Be Slowed by Wireless Carriers

The largest US telecommunication companies are slowing internet traffic to and from popular apps like YouTube and Netflix, according to new research from Northeastern University and the University of Massachusetts, Amherst. The researchers used a smartphone app called Wehe, downloaded by about 100,000 consumers, to monitor which mobile services are being throttled when and by whom, in what likely is the single largest running study of its kind. Among US wireless carriers, YouTube is the No. 1 target of throttling, where data speeds are slowed, according to the data. Netflix’s video streaming service, Amazon’s Prime Video and the NBC Sports app have been degraded in similar ways, according to David Choffnes, one of the study’s authors who developed the Wehe app.

From January through early May, the app detected "differentiation" by Verizon more than 11,100 times, according to the study. This is when a type of traffic on a network is treated differently than other types of traffic. Most of this activity is throttling. AT&T did this 8,398 times and it was spotted almost 3,900 times on the network of T-Mobile and 339 times on Sprint’s network, the study found. The numbers are partly influenced by the size of the networks and user bases. C Spire, a smaller privately held wireless operator, had the fewest instances of differentiation among U.S. providers, while Verizon had the most. Carriers say they’re throttling to manage internet traffic.