AT&T's testing the idea of limiting the amount of data that subscribers can use each month.
The Dallas-based telecom giant and the nation's biggest Internet service provider will initially try out the limits in Reno, Nevada. The results will determine whether the practice will be extending elsewhere.
Increasingly, Internet providers across the country are placing such limits on the amount of data users can upload and download each month. That's as a way to curb a small number of "bandwidth hogs" who use much of the network capacity. For instance, AT&T says 5 percent of its subscribers take up 50 percent of its capacity.
Starting in November, AT&T will limit downloads to 20 gigabytes per month for users of their slowest, 768 kilobits-per-second DSL service. The limit increases with the speed of the plan, up to 150 gigabytes per month at the 10 megabits-per-second level.
To exceed the limits, subscribers would need to download constantly at maximum speeds for more than 42 hours, depending on the tier. In practice, e-mail and Web surfing wouldn't threaten the limit but streaming video services like Netflix's could.
For example, subscribers who get downloads of 3 megabits per second have a monthly cap of 60 gigabytes, which allows for the download of about 30 DVD-quality movies.