Last week, hundreds of people around the United States, though online in certain areas, reported a drastic downturn in their upload speeds on AT&T. What was once upwards of 1Mbp/s had maxed out, overnight it seems, at 100Kbp/s. Rumours abounded that AT&T had intentionally capped upload speeds to alleviate the impact of the HSUPA chip found in the iPhone 4, which can increase upload speeds by up to 10x on the same 3G network.

Today, the carrier has informed TUAW that it was a problem with some Alcatel-Lucent equipment, and affected only 2% of their customer base.

AT&T and Alcatel-Lucent jointly identified a software defect — triggered under certain conditions - that impacted uplink performance for Laptop Connect and smartphone customers using 3G HSUPA-capable wireless devices in markets with Alcatel-Lucent equipment. This impacts less than two percent of our wireless customer base. While Alcatel-Lucent develops the appropriate software fix, we are providing normal 3G uplink speeds and consistent performance for affected customers with HSUPA-capable devices.

Glad to know that this is not a permanent policy change in light of added load on their towers. The improvements, apparently, have not been seen yet, and according to many posts, the problem seemed more widespread than just 2% of the customer base.

(TUAW)