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From: "Jonathan M. Bresler" <jmb>
Message-Id: <199707152004.NAA21101@hub.freebsd.org>
Subject: Re: Ping with standard deviation?
To: wollman@khavrinen.lcs.mit.edu (Garrett Wollman)
Date: Tue, 15 Jul 1997 13:04:08 -0700 (PDT)
Cc: current@freebsd.org
In-Reply-To: <199707151921.PAA12803@khavrinen.lcs.mit.edu> from "Garrett Wollman" at Jul 15, 97 03:21:20 pm
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Garrett Wollman wrote:
> 
> I just modified `ping' to output standard deviation in addition to the
> other statistics.  Does anyone out there think that this would be
> useful in the general case?
> 
> This gives output like:
> 
> --- lanrover.lcs.mit.edu ping statistics ---
> 81 packets transmitted, 81 packets received, 0% packet loss
> round-trip min/avg/max/stddev = 2.220/5.378/67.712/10.643 ms
> 
> (As you can see, there's an unfortunate amount of jitter in my
> network.)
> 
> It does increase the size of the ping executable a few K since we have

	std dev and avg (ping already prints avg) are very sensitive
	to outliers.  how using the statistics suggested by vern paxson
	instead?  median in place of average and inter-quartile range
	in place of std deviation.  (from memory, i'll have to get
	the phd thesis to check).
jmb