Nortel Networks Circuit Card 311 - Manual (Page 240)

240 NT5D11 and NT5D14 Lineside T1 Interface cards
Alarm parameters
The Set Alarm (S A) command set establishes the parameters by which an
alarm is activated, and its duration. There are three alarm activation levels:
• Alarm Level 0 (AL0) consists of activity with an error threshold below
the AL1 setting. This is a satisfactory condition and no alarm is activated.
• Alarm Level 1 (AL1) consists of activity with an error threshold above
the AL1 setting but below AL2 setting. This is a minor unsatisfactory
condition. In this situation, the external alarm hardware is activated
by closing the normally open contact. The RED ALARM LED on the
faceplate lights and an alarm message is created in the alarm log and
the MMI terminal.
• Alarm Level 2 (AL2) consists of activity with an error threshold above
the AL2 setting. This is an unsatisfactory condition. In this situation,
the external alarm hardware is activated by closing the normally open
contact. The RED ALARM LED on the faceplate lights and an alarm
message is created in the alarm log and the MMI terminal. The Lineside
T1 card enters line processing mode and a yellow alarm message is
sent to the CPE/CSU. Line processing sends the Meridian 1 either all
"on-hook" or all "off-hook" signals depending on the dip switch setting
of the card.
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 causes
the software to display a "Parameter Invalid" message. The threshold
number entered represents the respective power of 10 as shown in
Table
107 "T1 bit error rate threshold settings" (page 240) .
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 107
T1 bit error rate threshold settings
Alarm Threshold
bit errors per second
in Power of 10
Threshold
to set alarm
Allowable
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
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23 May 2008
Copyright © 2003-2008, Nortel Networks
.