Bandwidth Throttling May Not Appear to Function in Some Cases

• Microsoft Internet Information Services version 5.0

SYMPTOMS

When you use bandwidth throttling in Internet Information Services (IIS) 5.0, although you are throttling to a very small amount of bandwidth, IIS may transfer a larger amount. This only occurs in some fringe cases.

CAUSE

The bandwidth throttler keeps a histogram that tracks transfers during the last six ten-second intervals. Bandwidth information is updated every ten seconds. When the measured bandwidth starts at zero, it stays there for the first ten seconds of activity.

During that interval, a larger amount of bandwidth can be consumed. If you transfer large files, and have a low bandwidth limit, you will exceed the limit in one interval. At this point, the server blocks all transmissions for the next 60 seconds, as the interval moves across the histogram. After 60 seconds, the interval, where all transmissions occurred, drops off the histogram. At this point, measured bandwidth is zero, and another 10 seconds of unrestricted transmission occurs.

STATUS

Microsoft has confirmed this to be a problem in Internet Information Services 5.0.

Additional query words: iis ntop iis5 bandwidth throttling transfer

Keywords :
Version : winnt:5.0
Platform : winnt
Issue type : kbbug