AT&T DS1/DMi/ISDN-PRI User Manual

8-6

MAINTENANCE AND ALARMS

Generic 1 provides the same functional maintenance capabilities (such as error detection, error
logging, error testing, and alarm reporting) as Generic 2. However, because of hardware and
software differences and because Generic 1 uses the Manager rather than the Manager terminal, there
are several user-perceived differences.

For example, Generic 1 maintenance uses the concept known as maintenance objects (MOs). Each
type of circuit pack defines one or more MOs. Whenever an error is detected an entry is made in the
error log for the particular MO. Furthermore, an alarm level (major, minor, or warning), whether
the error was resolved as being on the circuit pack or off the circuit pack (such as a particular
trunking facility), and the circuit pack name are all listed in the error log.

NOTE:  Generic 1 MOs are similar to Generic 2 fault codes.

The hardware alarm report may be displayed at the Manager terminal by entering the 

d i s p l a y

alarms 

command. The suggested order for doing maintenance is to clear the alarmed troubles first

and then the non-alarmed troubles (that is, major alarms first, minor alarms second, and warnings
last). When multiple alarms (of the same level) are on, they should be cleared in the order specified
in chapter 8 of the  Generic 1 Maintenance Manual.

For both DS1/DMI, and ISDN-PRIs, the DS1-BD MO should be investigated first as a means of

resolving alarms associated with a DS1 circuit pack. This MO contains a series of tests, both
nondestructive and destructive, which may be used to verify the alarms. Specifically, these tests are:

Test 138

Loss of Signal Alarm Inquiry —  verifies the synchronization status of a DS1 link

Test 139

Blue Alarm Inquiry —  verifies that the distant end is out of service

Test 140

Red Alarm Inquiry  — checks the framing status of the link [for example, either out
of frame, loss of frame alignment (LFA) alarm, or no red alarm detected]

Test 141

Yellow Alarm lnquiry —  checks for a remote end out of frame or far end LFA

Test 142

Test 143

Test 144

Test 145

Test 146

Translation Update  — a destructive test that sends new or updated translations to a
DS1

Test 160

Remote-Loop Around —  used as part of the process to isolate transmission facility

failures

For ISDN-PRI facilities, the ISDN-TRK MO should be investigated to verify the service states of the
B-channels. The ISDN-LNK MO may be used to verify correct operation of the D-signaling channel.