Nortel Networks R2MFC Manuel D’Utilisation

Chapter 6 R2MFC MBM maintenance 65

R2MFC Media Bay Module Installation and Configuration Guide

Group II alarms occur when an alarm persists for a predefined period. The alarm is considered 
cleared when it does not occurred for a predefined period.

See 

 for incoming-signal Group II errors listed from highest to lowest priority. Group II 

errors are ordered by priority; when a high priority error exists, any errors of lower priority are 
irrelevant.

This section describes the actions taken when alarms occur or stop. When alarms occur, the 
far-end is alerted by a remote alarm indication, and an alarm is transmitted on the opposite link. 

 table shows the reactions for Group I alarms when they enter the Out-Of-Service (OOS) 

state. 

Table 11   Incoming signal errors

Loss of Signal (LOS)

No reception of incoming electrical signal on the line (cable cut or 

removed).

Alarm Indication Signal (AIS)

Reception of incoming signal is all ones. Usually indicates that the 

far-end is out-of-service

Out-of-Frame (OOF)

No detection of Frame Alignment Signal. The incoming signal is 

corrupted. This alarm is also known as Loss of Frame (LFA).

Out Of Multiframe TS16 - 

(OOM

TS16

)

No detection of Multiframe Alignment Signal. When this alarm is active, 

Channel Associated Signaling (R2) is impossible. This alarm is not 

applicable to the PRI (internal link). This alarm is also known as Loss of 

Multiframe Alignment - (LMA).

Alarm Indication Signal in TS16 

(AIS

TS16

)

Reception of AIS is all ones in TS16. This is an optional alarm. It can be 

enabled or disabled in configuration. By default, this option is off. When 

this alarm is active, any signaling on TS16 is impossible.

Loss of CRC-4 Multiframe 

Alignment (OOM)

CRC-4 multiframe cannot be recognized. When this alarm is active, 

CRC-4 errors (of group I) cannot be measured. This alarm is relevant 

only when CRC-4 multiframe mode is used.

Remote Alarm Indication (RAI)

Indication that the far-end has trouble with its incoming signal. This 

alarm is also known as yellow alarm.

Remote Alarm Indication TS16 

(RAI

TS16

)

Indication that the far-nd has lost TS16 multiframe alignment on its 

incoming signal.
This alarm is not applicable to PRI (internal link).

Table 12   Group I Alarms propagation (Sheet 1 of 2)

BPV

RAI

AIS

FBER

RAI

AIS

Slips

RAI

AIS