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Re: OT:Bandwidth and Billing [7:132233] posted 08/08/2008
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On 8/8/08, bobby kimble  wrote:

>  I have the following information for each server:
>  Avg Kbit/sec usage
>  95th percentile (5min)
>  Should I total up the Avg Kbit/sec or the 95% to determine the bandwidth
>  requirements?

An average of bandwidth usage would be the same as 50th percentile
billing, where 50% of the time, if the server had a bandwidth cap
equal to the average, then packets would not be delayed or dropped.

95th percentile would mean that 5% of the time, packets would have
been affected due to bandwidth restrictions.

What I'd do, to support things in a totally "business case backed with
science and stuff," is calculate one standard deviation above the
average for each server (would be the same as  84.1% billing) and
total up all those numbers. If you've got around 3-4 servers, that
should be enough to deal with the peak traffic spikes while still
using a comfortable amount of the pipe. Then play with the numbers,
throw darts, and consult your Magic 8-Ball.


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