Isolating the Problem
To verify the Ethernet connection, follow these steps:
Make sure that the RJ-45 connector is in good working condition; then plug it into the LAN port.
Check for LED activity on the LAN port. The left LED is green when an Ethernet connection is
established. The right LED flickers yellow when a signal is being transmitted to the Ethernet.
Check the following areas for possible problems if no LEDs are on:
To verify the alarm connection, connect an ohmmeter to the Alarm Out port, through an RJ-45 connector.
If the ohmmeter shows a reading of any kind, a connection is present. A very high resistance reading
indicates that there are no alarm conditions; a low resistance reading indicates that alarm conditions do
Isolating the Problem
The key to troubleshooting the Cisco ONS 15501 is to isolate the problem to a specific component.
When troubleshooting, consider the following components of the Cisco ONS 15501:
Reading the Front Panel LEDs
The front panel LEDs provide the activity or alarm status of the interfaces or internal circuitry to which
they correspond. If an LED is connected to an active circuit and registers an alarm condition or is not
on, a problem may exist.
If all LEDs on the front panel are off:
Cisco ONS 15501 User Guide
Verify that the RJ-45 connection to the chassis is firmly made.
Verify that the RJ-45 connector is in good working condition.
Verify that the external Ethernet source is on and delivering a signal.
Appendix B, "Connector Pinouts."
Power supply — Includes the power input wiring and associated switches and fuses.
Cooling system — Includes the fan, which should go on when power is supplied. The air intake vents
and exhaust vents must have adequate ventilation.
Front panel indicators — Includes the LEDs on the front panel, which help to identify a failure.
Connecting cables — Includes all of the interface cables that connect the equipment to any
transmission circuit or external device.
shows the Cisco ONS 15501 front panel.
Cisco ONS 15501 Front Panel LEDs
lists the front panel LEDs and what the conditions indicate.
Power is on.
Signal is detected.
78-14134-01, Release 1.0