Nortel Networks 1000 User Manual

Page 218

218

NT5D11 and NT5D14 Lineside T1 Interface cards

The alarms are activated in response to pre-set thresholds and error
durations. Descriptions of each of these T1 link alarm conditions,
instructions on how to configure alarm parameters, and access alarm
reporting can be found in

“Alarm operation and reporting” (page 235)

Two levels of alarm severity exist for bit errors and frame slip errors. For
these conditions, two different threshold and duration configurations are
established.

When the first level of severity is reached (alarm level 1), the MMI does
the following:

•

activates the external alarm hardware

•

lights the appropriate LED on the faceplate (either RED ALARM or
YELLOW ALARM)

•

displays an alarm message on the MMI terminal

•

creates entry in the alarm log

When the second level of severity is reached (alarm level 2), the MMI
performs all of the same functions as alarm level 1, and in addition, forces
the Lineside T1 card to enter trunk processing mode. In this mode, the
terminal equipment sends either "on-hook" or "off-hook" signals for all 24
ports to the CS 1000M, and Meridian 1, depending on how the dip switch
for trunk processing was set (dip switch #2, position #6).

If the MMI detects T1 link failures for any of the remainder of the
conditions monitored (out of frame condition, loss of signal condition, and
blue alarm condition), the Lineside T1 card automatically performs all
alarm level 2 functions. The MMI also sends a yellow alarm to the distant
end CPE or CSU.

Alarms can be configured to self-clear or not self-clear when the alarm
condition is no longer detected.

All alarms activated produce a record in an alarm log. The alarm log
maintains records for the most recent 100 alarms and can be displayed,
printed and cleared. The alarm log displays or prints the alarms listing
the most recent first in descending chronological order. The alarms are
stamped with the date and time they occurred.

MMI activates alarms for the following T1 link conditions:

•

excessive bit error rate

•

frame slip errors

•

out of frame condition

Nortel Communication Server 1000

Circuit Card Reference

NN43001-311

02.06

Standard

27 August 2008