Wireless Carrier Throttling of Online Video Is Pervasive

US wireless carriers have long said they may slow video traffic on their networks to avoid congestion and bottlenecks. But new research shows the throttling happens pretty much everywhere all the time. Researchers from Northeastern University and the University of Massachusetts Amherst conducted more than 650,000 tests in the US and found that from early 2018 to early 2019, AT&T throttled Netflix 70% of the time and Google’s YouTube service 74% of the time. But AT&T didn’t slow down Amazon’s Prime Video at all. T-Mobile US throttled Amazon Prime Video in about 51% of the tests, but didn’t throttle Skype and barely touched Vimeo. 

"They are doing it all the time, 24/7, and it’s not based on networks being overloaded," said David Choffnes, associate professor at Northeastern University and one of the study’s authors.