It turns out there's a lot more to BingeOn than "optimizing".
There's been a lot of talk for the last year or so over how closely T-Mobile walks the line between violating Net Neutrality with their features, and when BingeOn was announced that conversation got louder than ever. A service that promised to work with specific providers to make streaming video free, as long as you agreed to only stream in 480p from those providers. For budget-savvy consumers, this seemed like a pretty sweet deal. For anyone interested in making sure T-Mobile treats everything you do you on your phone the same way, it sounded like a nightmare that would no only be difficult to manage but next to impossible to keep from stepping on the toes of content providers who weren't partners.
A couple of weeks ago, YouTube — which is not a BingeOn partner — claimed T-Mobile was throttling content without explanation or permission. T-Mobile quickly responded with a statement claiming what YouTube viewers experienced was optimization, and not throttling. Thanks to some thorough testing from the EFF, we now know what T-Mobile is doing to videos that aren't included in BingeOn is exactly throttling, and brings the company even closer to the line between violating and not violating Net Neutrality regulations.
In reality, according to an EFF report, T-Mobile is actively throttling HTTP traffic.
As a service, BingeOn is fairly simple. You choose to turn it on, and the way it is supposed to work — meaning the way T-Mobile claims it works — is when the apps that partner with T-Mobile are streaming video they do so at 480p and that data doesn't count against your monthly data allotment. If you watch video from a non-BingeOn partner, your video is supposed to play the same way it would if BingeOn was disabled and count against your monthly data allotment as such, which makes sense. You agreed to play by T-Mobile's rules for a cheaper monthly bill by way of less data billed, and you sacrifice some video quality on a 5-inch screen such that many people wouldn't notice anyway. No big deal.
In reality, according to an EFF report, T-Mobile is actively throttling HTTP traffic down to 1.5mbps when BingeOn is enabled regardless of where you're getting your video from. This includes HTML5 video, video files downloaded to play directly on your device, and even video files that aren't directly labeled as such in the HTTP headers. There's no attempt at optimization, meaning no adjustments are being made to the files to make them perform better under these conditions. If the stream requires more than 1.5mbps to stream adequately and BingeOn is enabled, the stream stutters and buffers and the user has no idea it's because they have BingeOn enabled.
It doesn't look great, and T-Mobile should absolutely be more clear about how BingeOn performs, but it's also important to understand that the EFF report is functionally incomplete. There's still quite a bit we don't know about how T-Mobile's partner arrangements work, and that's an important part of whether it's a good idea to grab pitchforks and demand the FCC investigate, which is what the EFF suggests at the end of their report. What T-Mobile needs to do right now is stand up and be transparent about this process, and avoid using marketing nonsense to explain how this process is supposed to work. In the mean time, if you're a BingeOn customer and have had problems streaming video from non-partner services, there's a good chance you know where to point the finger right now.