Nortel Networks 5399 Access Switch Hardware Installation Guide
Chapter1 Introduction
1-10
Network Statu s and
Alarm LEDs The Network Status and Alarm LEDs display network activity during
system operation. Table 1- 3 describes thea larms.There are two sets ofNetwork Status and Alarm LEDs, one set for each WANport.TechnicalSupport personnel can use this information to diagnoseproblems.
Table1-3. Network Status and Alarm LEDs
Load Turnsgreen when the Remote Access Concentratoris loading the
operationalimage or dumping a RAM image if there is a failure.
TheL ED turns amber if a load error is detected.
LED Description
Alarm Description
TEST The network TEST in dicator is ON (amber) w hen the WAN
Interfaceis looped back. Loopback tests are activatedeither
locallyby the user or by the telephone company.
SYNC TheSYNC indicator is ON (green) when the WAN interfaceis
properlysynchronized with the received network signaland is
receivingproper framing information.
LOS The LOS indicatoris ON (amber) when the WAN interface is
detectinginvalid synchronization pulses on the network
interfacereceiver. When a LOS condition exists,t he Remote
AccessConcentrator transmits a YELLOW alarm to the
remote system.
RED The RED alarm indica tor is ON (amber) during alocal ly
detectedcarrier failure. During the RED alarm condition, a
YELLOWalarm is transmitted across the telephone network.
YELLOW TheYELLOW alarm indicator is ON (amber) whe n receiving
aYELLOW alarm condition from the telephone network. This
indicatesa failure detected at the other end of the link (the
Central Office).
BLUE The BLUE alarmindicator is ON (amber) when receiving an
unframed,all-ones Alarm Indication Signal (AIS) from the
network.This condition exists upon a loss of originating
signal,or when any action is takenthat would cause a signal
disruption.