Q239037: Bandwidth Throttling May Not Appear to Function in Some Cases

Article: Q239037
Product(s): Internet Information Server
Version(s): winnt:5.0
Operating System(s): 
Keyword(s): kbInternet kbDSupport kbiis500
Last Modified: 13-MAY-2000

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The information in this article applies to:

- Microsoft Internet Information Services version 5.0 
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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

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Keywords          : kbInternet kbDSupport kbiis500 
Technology        : kbiisSearch kbiis500
Version           : winnt:5.0
Issue type        : kbbug
Solution Type     : kbpending

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