DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126
Issue 4
June 1999
Additional Maintenance Procedures
6-13DS1 CPE Loopback Jack (T1 Only)
6
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.
Table 6-3. DS1 Span Troubleshooting
Displayed Field Function Indication
Test:
cpe-loopback-jack
Pattern 3-in-24 The loopback jack test is active.
Synchronized Y or N If “y” displays, the DS1 circuit pack has synchronized to
the looped 3-in-24 pattern and is accumulating a count of
the bit errors detected in the pattern until the test has
ended. If “n” displays, retry the test 5 times by ending the
test per Step 11 and re-starting the test per Step 4. If the
circuit pack never synchronizes, substantial bit errors in
the 3-in-24 pattern are likely. This could be intermittent
connections or a broken wire in a receive or transmit pair
in the CPE wiring.
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.
