Nortel Networks 1000 User Manual

Page 291

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Man-Machine E1 maintenance interface software

291

Invalid"

message. The digit entered as the threshold value is a number

representing a negative power of 10 as shown in

Table 111 "E1 bit error

rate threshold settings" (page 291)

.

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 111
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)

Nortel Communication Server 1000

Circuit Card Reference

NN43001-311

02.06

Standard

27 August 2008

Copyright © 2003-2008 Nortel Networks

.

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