Nortel Networks 553-3001-211 manual Threshold to set Allowable Duration, Periods

NT5D33 and NT5D34 Lineside E1 Interface cards Page 279 of 894

—an alarm message is created in the alarm log and the MMI terminal

—the LEI card enters line-conditioning mode

—a yellow alarm message is sent to the CPE/LTU

Line processing sends the CS 1000S, CS 1000M, and Meridian 1 either all “on-hook” or all “off-hook” signals, depending on the dip switch setting of the card. See Table 94 on page 258.

When the Set Alarm command is selected, the prompt appears for setting the threshold level and duration for alarm levels 1 and 2.

The E1 link processes at a rate of approximately 2.0 mb/s. The threshold value indicates the ratio of the total number of bits that must be detected as being in error per second before the LEI activates an alarm. It can be set between 3 and 9 and can be different for each alarm level. Any other value entered will cause the MMI to display a “Parameter Invalid” message. The digit entered as the threshold value is a number representing a negative power of 10 as shown in Table 101.

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 101

E1 bit error rate threshold settings (Part 1 of 2)

Alarm threshold bit
errors per second in	Threshold to set	Allowable Duration
power of 10	alarm	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

Circuit Card Description and Installation