Verizon Wireless customers complained this week that the company was throttling Netflix traffic. With talk of net neutrality ringing in their ears, people were upset to find that download speeds were capped at 10Mbps.
When Netflix denied implementing a cap, the finger of suspicion pointed at Verizon. Now the company has owned up to testing a new "video optimization" system, but it's not clear how this resulted in the cap-like effects experienced by many users.
Verizon Wireless customers found that using Netflix's own speed testing tool revealed a maximum transfer rate of 10Mbps. However, once a VPN was introduced, this speed jumped back up to what users would normally expect to see. While a limit of 10Mbps would only really have an impact on people watching ultra-high definition videos on their mobile devices (or on a tethered computer), this form of capping very much goes against net neutrality rules.
Verizon's explanation that the apparent capping was a side effect of a trial of a video optimization system is not likely to satisfy many customers, particularly when tests with VPNs seem to eliminate the cap.
A spokesperson for Verizon Wireless told Ars Technica:
We've been doing network testing over the past few days to optimize the performance of video applications on our network. The testing should be completed shortly. The customer video experience was not affected.
While the loudest complaints have been about Netflix, there have also been reports about capping of YouTube video from Verizon Wireless customers. This is in line with a statement issued to the Verge in which a spokesperson said: "We are constantly testing the network. It's what we do, to optimize performance for our customers. The test was across the board, and did not target any individual applications."