Current dip switch S2 settings (S1..S8) On Off On Off Off
Off On Off
Alarm operation and reporting
The MMI monitors the T1 link according to the parameters established through the Set Alarm
command set for the following conditions:
• Excessive bit error rate
• Frame slip errors
• Out of frame condition
• Loss of signal condition
• Blue alarm (AIS) condition
Descriptions of the excessive bit error rate and frame slip errors conditions can be found in
on page 180. Bit errors may activate either a level 1 or level 2 alarm.
The remaining conditions, when detected, always cause the system to activate a level 2
alarm.
An out of frame condition is declared if two out of four frame bits are in error. If this condition
occurs, the hardware immediately attempts to reframe. During the reframe time, the T1 link is
declared out of frame, and silence is sent on all receive timeslots.
A loss of signal condition is declared if a full frame (192 bits) of consecutive zeros is detected
at the receive inputs. If this condition occurs, the T1 link automatically attempts to
resynchronize with the distant end. If this condition lasts for more than two seconds, a level 2
alarm is declared and silence is sent on all receive timeslots. The alarm is cleared if, after two
seconds, neither a loss of signal, out of frame condition, nor blue alarm condition occurs.
If a repeating device loses signal, it immediately begins sending an unframed all 1's signal to
the far-end to indicate an alarm condition. This condition is called a blue alarm, or an Alarm
Indication Signal (AIS). If an AIS is detected for more than two seconds, a level 2 alarm is
declared, and silence is sent on all receive timeslots. The alarm is cleared if, after two seconds,
neither a loss of signal, out of frame condition, nor blue alarm condition occurs.
Alarm Disable
The Alarm Disable (A D) command disables the external alarm contacts. When this command
is typed, the MMI displays the message "Alarms Disabled" and the MAINT LED turns on. In
this mode, no yellow alarms are sent and the Lineside T1 card does not enter line processing
mode. Alarm messages are still sent to the MMI terminal and the LED light continues to indicate
alarm conditions.
Alarm Enable
The Alarm Enable (A E) command set does the opposite of the Alarm Disable command set.
It enables the external alarm contacts. When this command set is typed in, the MMI displays
NT5D11 and NT5D14 Lineside T1 Interface cards
184 Circuit Card Reference
July 2011
Summary of Contents for 1000 Series
Page 1: ...Circuit Card Reference Nortel Communication Server 1000 7 0 NN43001 311 04 04 July 2011 ...
Page 20: ...20 Circuit Card Reference July 2011 ...
Page 30: ...Introduction 30 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 116: ...Option settings 116 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 143: ...Figure 25 CP PIV card front Physical description Circuit Card Reference July 2011 143 ...
Page 148: ...NT4N39AA CP Pentium IV Card 148 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 287: ...Figure 86 Clock Controller Option 3 Operation Circuit Card Reference July 2011 287 ...
Page 302: ...NT5K21 XMFC MFE card 302 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 346: ...NT6D80 MSDL card 346 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 353: ...Figure 96 NTDK16 DLC Functional description Circuit Card Reference July 2011 353 ...
Page 461: ...Figure 147 Paging trunk operation Applications Circuit Card Reference July 2011 461 ...
Page 462: ...NT8D15 E and M Trunk card 462 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 500: ...NTAK09 1 5 Mb DTI PRI card 500 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 512: ...NTAK10 2 0 Mb DTI card 512 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 534: ...NTAK79 2 0 Mb PRI card 534 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 550: ...NTBK22 MISP card 550 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 560: ...NTBK50 2 0 Mb PRI card 560 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 595: ...Figure 165 MGC block diagram Introduction Circuit Card Reference July 2011 595 ...
Page 662: ...NTRB21 DTI PRI DCH TMDI card 662 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 668: ...NTVQ01xx Media Card 668 Circuit Card Reference July 2011 Comments infodev avaya com ...
Page 700: ......