Is AT&T Capping iPhone Data Upload Speeds?

Recently, many users from The MacRumors forums are comparing their recent upload speeds from their iPhone's and are complaining about what appears to be capped uploads at 100 kbps rather than the 1.6mbps norm. The users have been comparing rates captured with tools such as Speedtest.net's Speed Test to put numbers on the perceived performance drops, which is considerably large compared to the way things were just a week or two ago. According to the thread, affected cities include: NYC, Central Jersey, Boston, Orlando, Seattle, South Jersey/Philly, Columbus, Cleveland, West Houston, Phoenix, Northern Colorado, St. Paul/Minnesota, Suffolk County/Long Island, Quad Cities, South Jersey, Denver, Detroit Metro, and Cincinnati.

Upload speeds affect the ability to do things such as sending pictures and video-email over the 3G network, as well as to upload any kind of bandwidth-hungry data using your 3G connection. The folks over at TUAW gave the test a spin in Denver using SpeedTest.net's application as well as FCC Mobile Broadband Test and INetQCheck. They said they experienced as the ones reported by the Macrumors forumgoers. Comparing both runs on INetQCheck tests with those of SpeedTest.Net, many users didn't even crack 100kbps using 3G.

The question that arises is why the sudden change? AT&T has been contacted by several different people but everyone has yet to hear back from them due to the holiday. Our guess is that this comes in line due to AT&T's recent data plan changes, probably in an attempt to enforce data austerity and guard AT&T's business from high bandwidth demands. Some people suggest that the hypothetical upload caps are a consequence of holiday weekend infrastructure work and that speeds will return to normal tomorrow.

We will check and you can stay tuned for more info regarding the topic by following us on Twitter and/or subscribing to our RSS feeds.