Nortel Networks 553-3001-211 manual 280 of 894 NT5D33 and NT5D34 Lineside E1 Interface cards

Page 280 of 894 NT5D33 and NT5D34 Lineside E1 Interface cards

Table 101

E1 bit error rate threshold settings (Part 2 of 2)

Alarm threshold bit
errors per second in	Threshold to set	Allowable Duration
power of 10	alarm	Periods
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 will be declared. Low bit-error rates (107 through 109) are restricted to longer durations since it takes more than one second to detect an alarm condition above106. Higher bit-error rates are restricted to shorter durations because the MMI error counter fills at 65,000 errors.

The alarm indications (LEDs and external alarm contacts) will clear automatically after the specified period, or duration, has expired if the Set Clearing (S C) “Enable Self Clearing” option has been set. Otherwise, the alarm will continue until the command Clear Alarm (C A) has been 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 will be 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 have been 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.

A heavy bit-error rate can cause 200 bit errors to occur much more quickly than100 seconds. This causes the alarm to be declared sooner.

553-3001-211 Standard 2.00 September 2004