| Each central-site router has LED
displays that allow you to verify that the router components are
installed and functioning properly. For LED information that
is specific to your router, refer to the installation and
configuration guide that accompanied your router.
On the Cisco 3600 router, the LEDs on
the front of the router enable you to determine router performance
and operation, as shown in Figure .
The ready LED indicates that a functional module has been installed
in the indicated slot. If the LED is off, the slot is empty or the
module is not functional. The active LED blinks to indicate network
activity on the module installed in the indicated slot.
All network modules have an enable
(EN) LED, which indicates that the module has passed its self-tests
and is available to the router. Each Ethernet port has two
LEDs, as shown in Figure .
The activity (ACT) LED indicates that the router is sending or
receiving Ethernet transmissions. The link LED indicates that the
Ethernet port is receiving the link integrity signal from the hub
(10BASE-T only).
Each PRI network module has four LEDs
in addition to the enable LED, as shown in
Figure .
The LEDs and their descriptions follow:
- REMOTE ALARM designates a remote alarm condition, meaning the far-end equipment has a problem with the signal it is receiving from the upstream equipment.
- LOCAL ALARM designates a local alarm condition indicating a loss of signal, a loss of frame, or unavailability due to excessive errors.
- LOOPBACK designates a loopback condition in which signals are sent and then directed back toward their source from some point along the communications path. Loopback tests are often used to test network interface usability.
- CARRIER DETECT specifies that you received the carrier on the telephone company link that indicates whether an interface is active.
Digital modem module, shown in Figure
,
has five LEDs in addition to the enable
LED-one for each MICAŽ module bank. The LEDs blink during
initialization. After the enable LED comes on, the MICA module LEDs
indicate that the corresponding MICA module is functioning. If a
MICA module fails its diagnostics or if no MICA module is installed
in a position, its LED remains off.
Each port on the serial network
module has the additional LEDs, as shown in Figure . Descriptions of the LEDs follow:
- CN/LPConnect when green; loopback
when yellow
- RXCReceive clock
- RXDReceive activity
- TXCTransmit clock
- TXDTransmit activity
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