Cabletron Systems SPECTRUM, User Manual

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SMT/MAC Configuration 4-19
FDDI Management
Lost Count
Displays the number of MAC PDUs (Protocol Data Units include both tokens and
frames) that contain an unknown error, so their validity is in doubt. When the
MAC encounters a frame of this type, it increments the Lost Frame counter and
strips the remainder of the frame from the ring, replacing it with idle symbols.
Changing the Measurement of Data
Measurement fields located at the bottom of the FDDI MAC Chart window allow
you to change how the incoming data is measured:
• Absolute –– displays the chart variable values recorded in the device MIB
counters.
• Delta –– displays the difference in value for the selected data between the
current poll interval and the last interval.
• Cumulative –– displays the total since the Cumulative button was selected.
• Clear –– resets Cumulative totals to zero; this option is not available in the
Absolute or Delta modes.
To change the type of measurement, or to clear and restart Cumulative totals, click
mouse button 1 on the appropriate shadowed button.
To exit the FDDI MAC Chart window, click .
Viewing FDDI MAC Meters
To view the FDDI MAC Meters window, highlight an entry in the MAC
Configuration scroll list and click
. The FDDI MAC Meters window,
Figure 4-9 , will appear. Each of the meters provided displays a single statistic in a
format that lets you know at a glance if the counter is registering high, medium,
or low values.
Figure 4-9. FDDI MAC Meters Window