Table D-1 describes the LEDs on the Switch, and Table D-2 describes the LEDs on the ATM Module.

Table D-1 LEDs on the Switch

LED Name	Color/State	Indicates
MGMT (On the front of the Switch)	Green Green flashing Yellow Yellow flashing OFF	Switch and ATM Module are operating normally. Switch or ATM Module is either downloading software or initializing, (which includes a Power On Self Test). Switch has failed its Power On Self Test (POST) ATM Module failed its Power On Self Test (POST). No power to the Switch.
Module (On the front of the Switch) On older switches this LED is called Downlink Status	Green Green flashing Green (long on, short off) Yellow Yellow flashing OFF	ATM port enabled; link present. ATM port disabled; link present. This LED will flash until all configured LECs have successfully joined their ELANs. ATM agent software is not installed correctly, or the ATM Module has failed its POST (if the MGMT LED is flashing yellow). Switch has not recognized the ATM Module. The ATM Module is not installed, or a link is not present on the ATM port, or the ATM Switch is not on.

Table D-2 LEDs on the ATM Module

LED Name	Color/State	Indicates
Far End Status (On ATM Module)	Green OFF (and Link Status LED is Green) OFF (and Link Status LED is OFF)	The ATM Switch (for example, CoreBuilder 7000) has not detected an error on the ATM Module's transmit link. The ATM Switch at the far end of the connection has detected a problem with the ATM Module's transmit connection, and notified the ATM Module. For example, the transmit half of the ATM Module's cable has been disconnected at either the ATM Module end or ATM Switch end of the connection. The cable between the ATM Module and ATM Switch has been disconnected.
Link Status (On ATM Module)	Green OFF	A link is present on the ATM port, and the port is receiving valid SONET frames. The Link is not present on the ATM Port.
TX (On ATM Module)	Yellow OFF	The ATM port is transmitting Ethernet, LANE, Signalling or control frames. The ATM port is not transmitting cells.
RX (On ATM Module)	Yellow OFF	The ATM port is receiving data cells. The ATM port is not receiving incoming cells.