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Re: How do you (not how do I) calculate 95th percentile?
From: Warren Kumari <warren () kumari net>
Date: Wed, 22 Feb 2006 14:10:11 -0800

Doh! You are 100% correct.

I didn't take into account the fact that the counters are if(In|Out) *Octets* and NOT if(in/Out)*Bits*.

The point is that 64-bit counters are not likely to roll :-)


On Feb 22, 2006, at 12:24 PM, Alex Rubenstein wrote:

(I did this fast, and, who knows; I could be off my an order or two of magnitude)

Most people are using 64 bit counters. This avoids the wrapping problem (assuming you don't have 100GE and poll more then once every 5 years :-)).

2^64 is 18,446,744,073,709,551,616 bytes.

100 GE (100,000,000,000 bits/sec) is 12,500,000,000 bytes/sec.

It would take 1,475,739,525 seconds, or 46.79 years for a counter wrap.

Alex Rubenstein, AR97, K2AHR, alex () nac net, latency, Al Reuben
Net Access Corporation, 800-NET-ME-36, http://www.nac.net

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