Public Radio Group Finds iOS 6.0 Streaming Bandwidth Bug

The Public Radio Exchange (PRX), a clearinghouse for and producer of public radio programs, helped This American Life and other shows sort out an iOS 6.0-related spike in bandwidth usage by uncovering a bug in a fundamental part of the operating system.

PRX was asked by This American Life for help in figuring out a spike in bandwidth bills in October 2012, and found a similar problem in its own logs. It isolated the behavior to ensure its own streaming apps weren’t at fault. PRX’s analysis shows that apps that rely on iOS frameworks to handle networked audio streaming in iOS 6.0 make multiple overlapping requests for audio that substantially increase the total number of bytes downloaded. The blog entry noted that a 30 MB podcast consumed 100 MB by the completion of a streamed episode, an exact ratio (30 MB taking 100 MB) that we and our readers have seen as well.

PRX writes that the bug disappeared in 6.0.1 and couldn’t be replicated in iOS 5, nor did the group test anything but access via Wi-Fi. Nonetheless, we’re convinced that the problem isn’t limited to streaming media or Wi-Fi. Readers continue to post stories of massive data consumption over 3G, 4G, and LTE without using the Podcasts app or other streaming audio and video apps; that applies while they are within range of a Wi-Fi network in their homes and when they are using programs that allow disabling mobile broadband usage. Twitter users also immediately noted that they continue to have problems even after the iOS 6.0.1 update.

Our previous coverage includes Matt Neuburg’s deep dive, “Mysterious iOS 6 Cellular Data Usage: A Deeper Look” (24 October 2012) and my earlier examination, “What’s Behind Mysterious Cellular Data Usage in iOS 6?” (29 September 2012). Since this article was first published, Adam has written about the reappearance of DataMan Pro, an iOS app that can report on the cellular data usage of individual apps (see “Track Per-App Data Usage in iOS with DataMan Pro,” 20 November 2012).

If you continue to experience mysterious jumps in cellular data consumption and are charged for it by your carrier, we recommend asking customer service to remove the charges, and documenting your usage and any calls you make to the carrier about the issue in case you are required to make a claim later to obtain a refund.

(Hat tip to Michael Panzarino at The Next Web for the link to the story, and his reciprocal link to our previous coverage.)