Appendix F: Using the LineStatus Utility

Alarm LEDs

 

The following alarm LEDs indicate connection problems that

 

result from line failures:

 

 

 

LED

 

Meaning

 

 

 

LOS

 

Loss of Signal. Typically appears when no electrical signal is

 

 

detected. (check if line is plugged on the adapter and on the

 

 

network interface).

 

 

 

LOF

 

Loss of Frame (also known as Red Alarm) appears when many

 

 

frames are lost because of framing errors. The terminal is unable

 

 

to synchronize on the DS1 signal.

 

 

 

AIS

 

Alarm Indication Signal (also known as Blue Alarm).

 

 

Transmitted instead of the normal signal to maintain

 

 

transmission continuity. Also indicates to the receiving

 

 

equipment that a transmission interruption occurred either at the

 

 

equipment originating the AIS signal, or upstream of the

 

 

originating equipment.

 

 

 

RAI

 

Remote Alarm Indication (also known as Yellow Alarm).

 

 

Transmitted in the outgoing direction when a terminal

 

 

determines that it has lost the incoming signal.

 

 

 

iSPAN PRI PCI ISDN Users Guide

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