UM380 03 010
71
Problem Determination
Symptom
Higher than expected levels of unsuccessful call attempts.
Diagnostic action:
In a DPNSS environment some or all channels may be incorrectly configured at Layer 3 (set
to
X
or to
Y
at both ends) causing failure to resolve channel contention correctly. Therefore,
the configuration must be reviewed.
Symptom
DPNSS transparency is not achieved across a Q.931 network.
Diagnostic Action
The switching elements in Q.931 network do not support the Generic Functional Protocol, or
do not have this function enabled. Therefore, the configuration must be reviewed.
Symptom
DPNSS services requiring virtual calls do not work.
Diagnostic Action
Switching elements in the Q.931 network do not support non-call-associated signalling or do
not have this function enabled. Therefore, the configuration must be reviewed.
7.4.7 Fatal Errors
Symptom
Unexpected restart; calls in progress may be lost but the unit recovers within a couple of
minutes and on examination appears to be functioning normally.
Cause
The software has detected an error which it can not correct. The problem could be due to a
catastrophic hardware malfunction.
Any permanent hardware failure is discovered by the self test function and the unit will not
be returned to service. If the fault was transient, the unit re-initialises, clears any calls which
may have been left hanging, and resumes normal operation.
Once properly installed, configured and operational, InterChange iQ 2000 units are
extremely reliable. Software-detected errors are seldom seen and it is usually impossible to
diagnose the causative factors. Unless due to a persistent hardware problem, full recovery
within a couple of minutes is automatic, although calls in progress at the time of the failure
will have been cleared.
