DEFINITY ECS Release 8.2 Maintenance for R8.2csi
555-233-119 Issue 1
April 2000
Maintenance Objects
3-205ATM PNC-DUP (ATM PNC Duplication)
3
Demand PNC interchanges also invoke anti-thrashing , but only for a period of 30
seconds. During antithras hing mode, demand interchanges are also prevented
unless the override option is sp ecified.
!CAUTION:

Use of this option may cause a servic e 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 circ uit switched data may b e affected by the

following repair proce dures. This can happen, for examp le, when a slave

tone/clock circuit pack experi ences a l oss of signal and switches to receive

timing from the standby ATM-EI. In this case TDM-CLK 2305 error is logg ed,

and the clock p roblem should be ad dressed first, if possib le.

To repair PNC components in a duplicated PNC proceed as follows:
1. Most repairs involve fixing a sing le fault on the standby PNC. Use set pnc
lock or busy-out pnc to prevent an interchange into the PNC being
repaired.
2. If a faulty component exists on the ac tive PNC, this also means that the
standby PNC is more severely faulted. Normally, the

standby

PNC is
repaired first, since it is the mos t severely impaired.
To repair the active PNC (standby is already repaired ), issue the set pnc
unlock command, which g enerates a spontaneous interchange. In a PNC
demand interchang e with reset pnc interchange use the
override-and-lock qualifier for the active PNC. The

override-and-lock

option ensures that no subsequen t interchange can occ ur during the
repair of the standby PNC. A d emand interchange may not b e necessary
if the following conditio ns drive a spontaneous interchang e:
■The anti-thrashing period from the last interc hange has expired.
■The global refresh from releasing the standby PNC has completed.
■The standby PNC State of Health is better than the active PNC.
At this point, the faulty comp onent is on the standby PNC, and the PNCs
are locked in their current ac tive/standby state.
3. Busyout the PNC with the busyout pnc command.
4. Use fault isolation and comp onent testing proced ures for the individual
PNC components, just as for a simplex PNC. Replac ement of components
does disrupt op eration of the active PNC.