[ntp:questions] wedge scattergram questions

Richard B. Gilbert rgilbert88 at comcast.net
Tue Jun 5 11:18:28 UTC 2007


Werner Siedenburg wrote:
> Hello! In Mr. Mills' book I saw some interesting "wedge scattergrams".
> I have some questions about them:
> 
> 1. What is the exact use of these scattergrams?
> Mr. Mills writes that "the shape of the wedge reveals intimate details about
> the network path characteristics". How? The only thing I notice: The further
> left the
> apex of the scattergram is, the better (because of lower delay). What else
> can you see
> in them?
> 
> 
> 2. I understand that "under low traffic conditions, the points are
> concentrated about the apex of the wedge and begin to extend rightward along
> the limb lines as
> network traffic increases".
> 
> But why is the most accurate offset measured at the lowest delay?
<snip>

Because the maximum error in transmitting time from server to client is 
one half of the round trip delay!  It's usually better but can't be any 
worse.




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