User`s guide

7-6

Diagnostics and Troubleshooting

loopback tests, the ATX creates LLC Type 1 test packets for LANs,

and PPP echo-request packets for WANs and UARTs.

Both types of loopback tests can be initiated by the NMS, and test

results are reported to the NMS. Refer to the ATX MIB Reference

Guide for the MIB variables.

7.3.2 Diagnostic Results

ATX diagnostic results are indicated in two ways:

• By observing the front panel LEDs.

• By reading NMS trap messages.

Both power-up and loopback diagnostics produce traps, which are

sent to the NMS and may be logged for future reference. In some

cases it may be more convenient to simply observe the LEDs, but

in most cases traps provide more information. There are no LEDs

for the loopback tests; the results of these tests must be observed

by accurate packet transmission, or read by using an NMS to

examine traps.

7.4 STATUS AND ACTIVITY LEDS

The front panel of the ATX includes numerous LEDs which show

the status or activity of various system components.

During normal operation, the status of each LED (off, on, or

ﬂashing) should be as shown in Figure 7-1. The meaning of the

ATX base unit LEDs is explained in Table 7-1. The meaning of the

module LEDs are explained in the individual module manuals.

(For LED activity during power-up, See Chapter 2, Power-up

Diagnostics Sequence.