
4-3
Chapter 4 Troubleshooting Procedures
NortelNetworks 5399 Access Switch HardwareInstallation Guide
Table4-1. Model 5399 Front PanelLEDs (continued)
(continuedon next page)
LED(s) Description
ModuleStatus
LEDs (continued) Load- Turns green when the Remote Access
Concentratoris loading the operational image or
dumpinga RAM image if there is a failure. The LED
turnsamber if a load error is detected.
NetworkStatus
LEDs TEST - The network TEST indicator is ON (amber)
whenthe WAN Interface is looped back. Loopback
testsare activated either locally by the user or by the
telephonecompany.
SYNC -The greenSYNC indicatoris ON (green)
whenthe WAN interface is synchronized with the
receivednetwork signal and is receivingprope r framing
information.
LOS - The LOS indicator is ON (amber) when the
WANinterface is detecting invalidsynchronization
pulseson the network interface receiver. When an LOS
conditionexists, the WAN interfacetransmits a
YELLOWalarm to the remote system.
AlarmLED s RED- T he RED alarm indicatoris ON (a mber)during
alocally detected carrierfailure. During the RED alarm
condition,a YELLOW alarm is transmitted across the
telephonenetwork.
YELLOW- The YELLOW alarm indicator is ON
(amber)when receiving a YELLOW alarm condition
fromthe telephone network. This indicates a failure
detectedat the other end of the link (the Central
Office).
BLUE - The BLUE alarm indicator is ON (amber)
whenreceiving an unframed, all-ones Alarm Indication
Signal(AIS) from thenetwork. This condition exists
upona loss of originating signal, or when any action is
takenthat would cause a signal disruption.