PP Presentation

In the above plot, the loss and response time are measured during

SLAC prime time (7am - 7pm, weekdays), the other measures

are for all the time.

The hosts are grouped according to how they are connected to SLAC

and the geographical location of the site.

Within the groups the hosts are ranked by packet loss.

•The loss rates are plotted as a bar graph above the y=0 axis and are for 100 byte

payload ping packets. Horizontal lines are indicated at packet losses of 1%, 5%

and 12% at the boundaries of the connection qualities defined above.

•The response time is plotted as a blue line on a log axis, labelled to the right, and is

the round trip time for 1000 byte ping payload packets.

•The host unreachability is plotted as a bar graph negatively extending from the y=0 axis.

A host is deemed unreachable at a 30 minute interval if it did not respond to any of the

21 pings made at that 30 minute interval.

•The host unpredictability is plotted in green here as a negative value, can range from

0 (totally unpredictable) to 1 (highly predictable) and is a measure of the variability of

the ping response time and loss during each 24 hour day.

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