Maintenance for CSI systems
555-233-119
90
Issue 5 October 2002
Figure 6.
Processing of ISDN-PRI Problems (Page 2 of 2)
Troubleshooting PRI Endpoint Problems
The following flowchart,
Figure 7 on page 91
and
Figure 8 on page 92
, defines a
layered approach when troubleshooting PRI endpoint problems. Since a problem
at a lower layer affects upper layers, layers are investigated from low to high. In
the flowchart, the DS1 facility is layer 1, the TN765 Processor Interface is layer 2,
and the ISDN trunks are layer 3.
PAGE
YES
END
A
FROM
1
ARE
THERE
TRANSIENT
PROBLEMS MAKING
ISDN-PRI
ARE
THERE BIT
ERRORS OVER
HAS A
SYNCHRONIZATION
SOURCE BEEN
SYSTEM SWITCHING
IF PROBLEMS
STILL EXIST,
THEN ESCALATE
COMPARE INDICATED
FACILITY TO RECORD
OF PREVIOUS PROBLEMS
ARE BIT
ERRORS OCCURRING
MORE FREQUENTLY
THAN PREVIOUS
RECORD INDICATED
FACILITY AND, IF THIS
CONTINUES TO OCCUR,
CONTACT FACILITY OR
EXTERNAL EQUIPMENT
THE TI FACILITY?
UNSTABLE?
AWAY FROM IT?
NO
YES
SEE DS1-BD MO FOR
REPAIR PROCEDURES IF
SYNC PROBLEM IS DUE
TO SLIPS. OTHERWISE,
FOLLOW REPAIR
PERFORM AN IN-DEPTH
ANALYSIS OF T1
FACILITY INCLUDING:
TRANSMISSION FACILITY,
EXTERNAL EQUIPMENT
AND ANY OTHER
NOISE-PRODUCING
EQUIPMENT.
REFER TO AT&T PRACTICE
855-351-101 ISSUE 8,
JANUARY 1987. THIS
DESCRIBES T1 CABLING TO
(DACS, CSUs, ETC.,)
CSUs, ETC, IN DETAIL
YES
NO
NO
NO
YES
END
CALLS
SEE SYNC MO
HISTORY
PROVIDER. THEN ESCALATE
PROCEDURES FOR
SYNC MO
USE LIST
MEASUREMENTS
COMMAND