Managing System Alarms 169Alarms Common to Several InterfacesTable 27 describes major alarms common to several PathBuilder S330/S310interfaces.Table 27 Alarms Common to Several ModulesAlarm Meaning Troubleshooting StepsAlarm IndicationSignal(AIS)An incoming alarm indicationsignal (AIS) indicates a LOSproblem is occurring on theline upstream of theequipment connected to thisport.Check your locally connectedDS3/E3/OC3 equipment, or ask yourservice provider to trace the source ofthe AIS signal.Far End ReceiveFailureThe far end equipment has aproblem with the signal it isreceiving from the PathBuilderdevice.Check for a defective cable betweenthe PathBuilder device networkinterface port and your serviceprovider’s network interface unit. Anopen transmit line can cause thiscondition. Check the LBO setting of theport.FEAC Loopback A DS3 overhead function thatallows the system to beenabled or disabled forresponding to Far End AlarmCondition commands from thecentral office. When enabled,the DS3 line loopback is put upupon instruction from thecentral office. The systemremoves the loopback uponinstruction or after 15 minutes.Check with your service provider todetermine the reason for the loopback.Idle Signal The line has not beenprovisioned for service. No datawill pass on a line with an idlesignal.Check the configuration of the terminalequipment, or have your serviceprovider check their equipment andmake sure it is provisioned for service.In Band Loopback A loopback is configured onthe port. Loopbacks are fortroubleshooting only andshould not be present undernormal operating conditions.If you are not troubleshooting the port,turn off the loopback.Link Down Summary informational alarmto indicate one or more alarmson this link are active.Information only.Link Up Summary informational alarmto indicate all alarms on thephysical link are cleared.Information only.Local CardLoopbackA loopback is configured onthe port. Loopbacks are fortroubleshooting only andshould not be present undernormal operating conditions.If you are not troubleshooting the port,turn off the loopback.Loss of CellDelineation(LOCD)Loss of celldelineation—possibly aframing or timing problem.Check the reference clock source.Compare parameters between localand service provider end. Check thephysical layer.(continued)
