DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126 Issue 4
June 1999
Maintenance Object Repair Procedures
9-232ATM PNC-DUP (ATM PNC Duplication)
9
■If a reset system 1 (warm) takes place d uring a PNC interchange, the
reset is escalated to level 2 (cold 2).
Fault isolation using Duplicated PNC
In some cases, PNC duplication can aid in the fault isolation procedure. PNC
interchanges can b e used to help isolate the faulty hardware. Two examples
demonstrating this techniq ue follow:
1. There is a fault that can occur in either the PPN ATM-EI or the PKT-INT
which cannot be read ily attributed to one board o r the other. If the packet
bus transceivers on either the PKT-INT or ATM-EI fail, the two boards
cannot communicate, b ut it will not be clear which b oard is at fault. In this
case, a planned interc hange of the PNC can be used to ind icate which of
the two boards.
— If the interc hange cures the problem, the ATM-EI was at fault.
— If the interc hange does not cure the prob lem, the PKT-INT is
suspect, provid ed there are no PKT-BUS faults.
2. A similar relationship exists for the EPN Archangel (EAA - the ac tive
ATM-EI) and certain TDM bus problems. If the EAA is unable to
communicate with a por t board over the TDM bus, either the EAA has a
fault, the port board has a fau lt, or there is a problem with the TDM bus
itself. If TDM bus maintenance tests find no p roblems with the bus, then it
is either the port board or th e EAA. It may be simpler to replace the p ort
board than to request a PNC interchang e. However, if it is not clear which
port board may b e at fault or maintenance is being p erformed remotely,
verify that the EAA is not at fault by executing a PNC interchange. If the
interchange solves the prob lem, then the EAA is faulty. If the problem
persists after the interchange, b ut TDM bus maintenance finds no
problem, then the port b oard is faulty.
Error Log entries
Whenever a PNC interchange takes place, an error is l ogged against PNC-DUP
with a code that conveys in formation about the cause of the interchang e and
which PNC became active. There are no alarms assoc iated with PNC-DUP
errors, but there should be an alarm ag ainst the PNC component that caused the
interchange. There are no PNC-DUP test sequences, but status pnc p rovides
information regarding the status o f the PNCs. The information in Table 9-98 and
Table 9-99 can help to identify which areas of the Alarm Log to investigate to find
the source of the problem.