Nortel Circuit Card 311 Reference page 299

Table 125
E1 bit error rate threshold settings
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
restricted to longer durations since it takes more than one second to detect
an alarm condition above10
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:
•
•
•
•
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.
Copyright © 2003-2008, Nortel Networks
.
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.
Alarm threshold bit
errors per second in
power of 10
10 -3
10 -4
10 -5
10 -6
10 -7
10
-8
10 -9
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)
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23 May 2008
Man-Machine E1 maintenance interface software 299
Threshold to set
alarm
2,000/ second
200/second
20/second
2.0/second
2.0/10 seconds
2.0/100 seconds
2.0/1000 seconds
6 . Higher bit-error rates are restricted to shorter
Allowable Duration
Periods
1-21 seconds
1-218 seconds
1-2148 seconds
1-3600 seconds
10-3600 seconds
100-3600 seconds
1000-3600 seconds
7 through 10 9 ) are