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Man-Machine E1 maintenance interface software 299
Note: The error-rate threshold for a level 2 alarm must be greater (a
smaller power of 10) than for a level 1 alarm. Remember that the
numbers being represented are negative numbers. Since 3 represents
–3, and 4 represents –4, 4 represents a smaller number than 3 does.
Table 125
E1 bit error rate threshold settings
Alarm threshold bit
errors per second in
power of 10
Threshold to set
alarm
Allowable Duration
Periods
10
-3
2,000/ second 1-21 seconds
10
-4
200/second 1-218 seconds
10
-5
20/second 1-2148 seconds
10
-6
2.0/second 1-3600 seconds
10
-7
2.0/10 seconds 10-3600 seconds
10
-8
2.0/100 seconds 100-3600 seconds
10
-9
2.0/1000 seconds 1000-3600 seconds
The duration value is set in seconds and can be set from 1 to 3,600 seconds
(1 hour). This duration value indicates how long the alarm condition must
last before an alarm is declared. Low bit-error rates (10
7
through 10
9
) are
restricted to longer durations since it takes more than one second to detect
an alarm condition above10
6
. Higher bit-error rates are restricted to shorter
durations because the MMI error counter fills at 65,000 errors.
If the Set Clearing (S C) "Enable Self Clearing" option is set, the alarm
indications (LEDs and external alarm contacts) is automatically cleared after
the specified period, or duration, expires. Otherwise, the alarm continues
until the command Clear Alarm (C A) is entered.
When an alarm is cleared, all activity caused by the alarm indications is
cleared:
•
the external alarm hardware is deactivated (the contact normally open
is reopened)
•
the LED goes out
•
an entry is made in the alarm log of the date and time the alarm was
cleared
•
carrier-fail line supervision ceases (for alarm level 2 only)
If self-clearing alarm indications are disabled, carrier-fail line supervision
terminates when the alarm condition has ceased, but the external alarm
contact and faceplate LED remain active until the alarm is cleared.
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23 May 2008
Copyright © 2003-2008, Nortel Networks
.