4-3Chapter 4 Troubleshooting ProceduresNortel Networks 5399 Access Switch Hardware Installation GuideTable 4-1. Model 5399 Front Panel LEDs (continued)(continued on next page)LED(s) DescriptionModule StatusLEDs (continued)Load - Turns green when the Remote AccessConcentrator is loading the operational image ordumping a RAM image if there is a failure. The LEDturns amber if a load error is detected.Network StatusLEDsTEST - The network TEST indicator is ON (amber)when the WAN Interface is looped back. Loopbacktests are activated either locally by the user or by thetelephone company.SYNC - The green SYNC indicator is ON (green)when the WAN interface is synchronized with thereceived network signal and is receiving proper framinginformation.LOS - The LOS indicator is ON (amber) when theWAN interface is detecting invalid synchronizationpulses on the network interface receiver. When an LOScondition exists, the WAN interface transmits aYELLOW alarm to the remote system.Alarm LEDs RED - The RED alarm indicator is ON (amber) duringa locally detected carrier failure. During the RED alarmcondition, a YELLOW alarm is transmitted across thetelephone network.YELLOW - The YELLOW alarm indicator is ON(amber) when receiving a YELLOW alarm conditionfrom the telephone network. This indicates a failuredetected at the other end of the link (the CentralOffice).BLUE - The BLUE alarm indicator is ON (amber)when receiving an unframed, all-ones Alarm IndicationSignal (AIS) from the network. This condition existsupon a loss of originating signal, or when any action istaken that would cause a signal disruption.
