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Token Errors
Claim Token
Lost Frame
Frame Count
Beacon
Ring-Level Station Alarms
When you set a ring-level station alarm (using the fields in the section of the
window labeled Station Errors), the alarm threshold will be applied to all stations
inserted into the currently monitored ring network. These values will override
any pre-set station-level alarms, so these fields can be used to quickly apply one
set of station-level alarm limits to all stations on the ring.
Ring-Level Alarm Limits
The threshold of errors requiring the management
station (while acting as the active monitor) to transmit a
token onto the monitored ring before it issues an alarm.
The default value is 10.
The number of times that a claim token can be released
by ring stations within the given time base before an
alarm is triggered. A claim token is released by a ring
station when it detects that the active monitor is absent
or malfunctioning. Stations receiving the claim token will
participate in the monitor contention process to
determine a new active monitor. The default value is 5.
The number of lost frames that the management station
transmits onto the monitored ring before triggering an
alarm. Lost frames are frames that do not return before
the management station's Timer Return to Repeat (TRR)
timer expires. These can be caused by stations entering or
leaving the ring during frame transmission. The default
value is 10.
The number of frames that can be transmitted on the ring
within the time base before the alarm limit is reached.
For a network running at 16 Mbits/sec, the default value
is 33,890. This number represents the maximum
bandwidth used by 64 byte frames transmitted over the
network during the default 10 second alarm time base.
For a network running at 4 Mbits/sec, the default value
is 18,920 (of 64 byte frames).
The number of beacons that can be detected on the ring
within the time base before the alarm limit is reached. A
station transmits a beacon when its monitor contention
timer expires, indicating that an Active Monitor could
not be elected. Beaconing provides a method for the
beaconing station and its NAUN to check their lobe
wiring and to begin the monitor contention process if
necessary. The default value is 1.
Token Ring Alarms
4-3
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