You're downloading a file, or calling up a Web page. Suddenly, the cyberworld goes into suspended animation.

Why can't the Internet provide more consistent service? One reason is a lack of insight into the overall pattern of traffic on the Internet. Now, researchers at AT&T Laboratories have come up with some surprising answers to what's going on.

If you look at a plot of traffic through a network point over a minute, the trace will fluctuate wildly from one fraction of a second to another-an expected result. Now look at a day broken up in units of 100 seconds. On a voice network, the curve flattens out; instantaneous variations cancel each other out. But on the Internet, the AT&T researchers found the pattern of traffic had the same "bursty" character over long time periods as over short ones.