Cabletron Systems SPECTRUM TRMMIM, User Manual

Page: 79 / 120

Using the Find Options 3-29
Ring Map
To find the station by Highest or Lowest number of frames processed or errors
detected:
1. Click on , and drag down to select By Highest or By Lowest.
2. Drag to the right to select the performance or error parameter of interest, and
release.
The station experiencing the highest or lowest number of the selected
parameter (according to the selected calculation mode) will be highlighted in
the map, and a window will appear, displaying the MAC address, node name
(if assigned), board and port index (if the station is connected to the
monitored hub), and the station’s measurement of the selected parameter.
See
Figure 3-14 , following page, for some sample windows.
NOTE
The statistics used to rank stations in highest—>lowest or lowest—>highest occurrence
of a particular parameter are measured at the end of the specified polling interval and are
displayed according to the selected calculation mode. Remember, the calculation mode is
global in nature; that is, when you change modes, it affects all statistics — including
those used to rank stations in highest or lowest order.
When Rate is the selected mode, Find by Highest or Lowest detects the station with the
greatest or smallest rate of frames processed or errors detected within a polling interval.
The following formula is used to find the station with the highest or lowest rate of frames
or errors:
∆
Frames or Errors measured/
∆
Time (in seconds)
For example, if one station detects 250 total errors over a 10 second poll interval (250/10
= 25 errors per second), and a second station detects 170 errors over the same 10 second
interval (170/10 = 17 errors per second), the first station is found to have a higher error
rate than the second.
When Cumulative is selected, selecting By Highest or Lowest will display the station
with the greatest or smallest number of frames or errors detected since the cumulative
option was last selected.
When Delta is selected, selecting By Highest or Lowest will display the station with the
greatest or smallest number of frames or errors detected during the last poll interval.
Note, too, that changing the calculation mode may change the rankings; a station that has
had a high rate of traffic in recent polling intervals may or may not have processed the
greatest cumulative number of packets, and so on.