User's Manual

DEFINITY ECS Release 8.2 Maintenance for R8.2csi 555-233-119 Issue 1
April 2000
Maintenance for csi systems
1-75Install DS1 CPE Loopback Jack (T1 Only)
1
9. Repeat Steps 5 through 8 as desired to observe bit error rate
characteristics. Also, wait 1 to 10 minutes between Steps 5 through 7. One
minute without errors translates to better than a 1 in 10 to the eighth error
rate. Ten minutes without errors translates to better than a 1 in 10 to the
ninth error rate.
10. If the test runs for 1 minute with an error count of 0, confirm that the 3-in-24
pattern error detector is operating properly by entering
test ds1-loop
<location> inject-single-bit-error
. This causes the 3-in-24 pattern
generator on the DS1 circuit pack to inject a single-bit error into the
transmit pattern. A subsequent
list meas ds1 summary <location>
command displays the bit error count. If a count greater than 1 is
displayed, replace the ICSU and retest. If the problem continues, replace
the DS1 circuit pack.
11. Terminate the test by entering
test ds1-loop <location> end
cpe-loopback-jack-test
. Wait about 30 seconds for the DS1 to re-frame
on the incoming signal and clear DS1 facility alarms.
Loopback termination fails under the following conditions:
a. The span is still looped somewhere. This could be at the loopback
jack, at the ICSU, or somewhere in the network. This state is
indicated by a fail code of 1313. If the red LED on the loopback
jack is on, replace the ICSU. Re-run the test and verify that the
loopback test terminates properly. If not, replace the DS1 circuit
pack and repeat the test.
Bit Error Count Cumulative
count of
detected
errors
If there are no wiring problems, the counter
remains at 0.
A count that pegs at 65535 or continues to
increment by several hundred to several
thousand on each list meas command execution
indicates intermittent or corroded connections,
severe crosstalk, or impedance imbalances
between the two conductors of the receive pair or
the transmit pair. Wiring may need replacement.
Note that “ESF error events” counter and the ESF
performance counter summaries (“errored
seconds”, “bursty errored seconds”, and so forth)
will also increment. These counters are not used
with the loopback jack tests. However, they will
increment if errors are occurring. Counters should
be cleared following the test.
Table 1 -7 . DS1 Span Troubleshooting — Continued
Displayed
Field Function Indication
Continued on next page