DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126
Issue 4
June 1999
Maintenance Object Repair Procedures
9-230ATM PNC-DUP (ATM PNC Duplication)
9
2. The PPN ATM-EIs are interchanged, indicated by the new standby ATM-EI
yellow LED off and the new active ATM-EI yellow LED on steady.
3. One by one the EPN ATM-EIs are interchanged as indicated by new
standby ATM-EI yellow LED turning off and the new active ATM-EI yellow
LED flashing (2 seconds on/200 milliseconds off). At this point the
interchange is functionally complete.
Certain conditions may interfere with the normal execution of the interchange:
1. In a faulted spontaneous interchange, it is possible the EPN/EPNs directly
affected by the fault will be the last to interchange.
2. A user directly affected by the single fault instigating a PNC interchange
can experience a momentary voice path outage during the switch.
3. If faults exist on both the standby and active PNC, it is possible to have
some EPNs go out of service while others are returned to service.
In any multifault situation, rely on
status pnc
to determine which is the active
PNC.
PNC duplication informs Timing Synchronization maintenance when a PNC
interchange has been completed and indicates which PNC is active. This causes
Synchronization to audit and ensure that the primary source for synchronization
of Tone-Clocks in each PN is supplied by a path associated with the active PNC.
Antithrashing and PNC interchanges
Following a spontaneous PNC interchange, subsequent PNC interchanges are
prevented for 5 minutes. This condition is indicated by
y
in the
Interchange
Disabled?
field of the
status pnc
screen. After 5 minutes, the antithrashing,
timer expires, interchange decisions are re-enabled, and the field displays
n
.
Should a catastrophic failure occur on the active PNC during the period when the
Interchange Disabled?
field is set to “yes,” there will be no spontaneous
PNC interchange.
Demand PNC interchanges also invoke anti-thrashing, but only for a period of 30
seconds. During antithrashing mode, demand interchanges are also prevented
unless the override option is specified.
!
CAUTION:
Use of this option may cause a service disruption.
Repairs on the standby PNC components
!
CAUTION:
If there is a TDM-CLK alarm, system timing may be routed through part of
the standby PNC, and circuit switched data may be affected by the
