Meaningful varience from Cisco RTR agent (data networks)?
Message posted by Stuart (via 166.44.137.198) on November 3, 2001 at 3:13 PM (ET)

I have an application that can gather statistics on round trip times in a data network.

It gives:
Number of Samples
Sum of Samples
Sum of Samples^2
(also Min & Max)

The samples are not recorded.

From those I can derive a Varience if it was normal distribution, but in data networks, the lower bound will be reasonably fixed.

Call it half a bell curve extending right with maybe "small" left portion.

It will never be less than A, normally be A + a bit, and will stretch to A + Variance.

I'm sure this isn't too hard but too long since Stats courses :-/

Regards,
S.

READERS RESPOND:
(In chronological order. Most recent at the bottom.)

Re: Meaningful varience from Cisco RTR agent (data networks)?
Message posted by Tomi (via 154.32.143.41) on November 3, 2001 at 11:38 PM (ET)

Presumably you want a model that will help you make predictions.

What you are describing could be a truncated normal distribution (tricky to calculate but possible). More likely it is a Poisson distribution, as these are common in data transmission problems.

To decide on the best model I would need to see the data. You could send me an email with .csv or .txt attachment to t.owens@hautlieu.sch.je

I teach Statistics and it would be interesting for my students to consider this if you don't mind them seeing your data.

Re: Meaningful varience from Cisco RTR agent (data networks)?
Message posted by Shang-Pin Chang (via 163.28.64.112) on December 9, 2001 at 1:34 PM (ET)

If you're also interested in its jitter statistics, Laplacian distribution looks good.

Shang-Pin
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Cisco Systems, Inc.