Nortel Networks 553-3001-211 manual NT5D11 and NT5D14 Lineside T1 Interface cards Page 221

NT5D11 and NT5D14 Lineside T1 Interface cards Page 221 of 894

When the Set Alarm command is used, a prompt appears to set the threshold level and duration period for alarm levels 1 and 2.

The threshold value indicates the number of bit errors detected per second that is necessary to activate the alarm. The T1 link processes at a rate of approximately 1.5 mb/s. The threshold value can be set between 3 and 9 and can be different for each alarm level. Any other value entered will cause the software to display a “Parameter Invalid” message. The threshold number entered represents the respective power of 10 as shown in Table 84.

Note: The error rate threshold for a level 2 alarm must be greater (a smaller power of 10) than for a level 1 alarm.

Table 84

T1 bit error rate threshold settings

Alarm threshold
bit errors per second	Threshold	Allowable
in power of 10	to set alarm	duration periods
10–3	1,500/second	1–21 seconds
10–4	150/second	1–218 seconds
10–5	15/second	1–2148 seconds
10–6	1.5/second	1–3600 seconds
10–7	1.5/10 seconds	10–3600 seconds
10–8	1.5/100 seconds	100–3600 seconds
10–9	1.5/1000 seconds	1000–3600 seconds

The duration value is set in seconds and can be set from 1 to 3600 seconds (1 hour). This duration value indicates how long the alarm will last. Low bit error rates (10-7through 10-9) are restricted to longer durations since it takes more than one second to detect an alarm condition above 10-6. 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) clear automatically after the duration period has expired, if the Set Clearing (S C) “Enable Self

Circuit Card Description and Installation