| In technology, an attempts to calculate traffic floods _before_ real | congestion appear cause a lot of useless work - and sometimes simple | models (like liquid etc) are working best. Correct. Most traffic engineering work uses historical data to determine where the hot spots already are. No prediction is necessary. Given the law of large numbers and the periodicity of Internet traffic, this seems to be a very good predictor of future behavior. Of course, this is congestion in the large, with only low frequency components. It says nothing about high frequency congestion. Tony