Nortel BM450 Troubleshooting Manual page 23

Figure 3 DTM LEDs
Power LED
Status LED
In service LED
Loopback test LED
Receive LEDs
Transmit LEDs
The table DTM LED functions
Table 4 DTM LED functions
LED Status
Power –
Status –
In service Flashing
Loopback test On
Receive alarm On
Receive error On
Transmit alarm On
Transmit error On
All LEDS Flashing
on page 23 describes the functions of the DTM LEDs.
Descriptions
See "Media bay module LEDs (expansion units only)"
See "Media bay module LEDs (expansion units only)"
The T1, ETSI, or PRI trunks are out of service because a loopback test is
running or the DTM is initializing.
A continuity loopback test is running.
A problem with the received digital transmission. This half-duplex link does
not work.
A small error as a result of degraded digital transmission. Possible causes are
an ohmic connection, water ingress, or too long a loop.
The DTM cannot transmit. The DTM sends an alarm indication signal (AIS) to
the terminating switch. This half-duplex link does not work.
The DTM is sending a remote alarm indication (RAI) carrier failure alarm
(CFA) to the terminating switch. If the transmit alarm is not on, this error
indicates a far-end or cable problem.
The DTM is initializing.
Chapter 3 Hardware Troubleshooting
for details.
for details.
BCM450 Troubleshooting Guide
23