DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126 Issue 4
June 1999
Maintenance Architecture
1-26Power Interruptions
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5. If memory shadowing is suc cessfully turned on, initiates the p rocess of
overall memory refresh
6. When refresh completes, if there are no critical c omponent major alarms,
raises the standby SPE’s SOH to level
functional
Stand by SPE in itial izati on is a lower prio rity t han in itial izing the a ctiv e SPE and is
therefore “paced” to lower CPU consumption. The above steps are carried out at
10 second intervals. During system initialization, the above sequenc e begins
about 2 minutes after the terminal log in prompt becom es available. Normally, the
standby SPE should be fully initialized about 5 minutes after the availability of the
login prompt. You can follow the execution of this sequence by rep eatedly
entering the command “ status spe.”
Should a step of this initialization sequenc e fail, system software retries that step
at 30 second intervals until it suc ceeds. It does not proc eed to the next step until
the current one has succeed ed. The failed condi tion is alarmed.
A pro ced ure for brin ging up t he sta ndb y SPE aft er be ing i n the SPE- down or
locked modes is d escribed at the end of Chapter 4, ‘‘In itialization and Recovery’’.
Power Interruptions
System cabinets and their assoc iated power supp lies can be powered by
110/208 volts AC either directly or from an Uninterrup tible Power Supply (UPS)
system. Alternatively, the cabinets and their power supplies may be powered by
a -48 VDC battery power plant, which req uires DC-to-DC conversion power units
in the system.
If power is interrupted to a DC-powered cabinet or an AC-powered cabinet
without optional backup batteries, the effect dep ends upon the dec ay time of the
power distribution unit. If the i nterruption period is shorte r than the decay time,
there is no effect on service, though som e -48V circuits may experience some
impact. If the dec ay time is exceeded for a PPN, all service is dropped,
emergency transfer is invoked and the system must reboot when p ower is
restored. If the decay time is exc eeded for an EPN, all service to that Port
network is dropped and the EPN must be reset when power is restored. If the
EPN contains a Switch Node carrier, all servic e to Port Networks connected to
that Switch Node is dropped.
Single-carrier cabinets, w hich can be used for EPNs, also have no battery
backup. If p ower is interrupted for more than 0.25 sec onds, all service is
dropped, and emergency transfer is invoked for the EPN.
In the above cases, the c abinet losing power is unab le to log any alarms.
However, in the case of an EPN going down while t he PPN remains up, alarms
associated with the EPN will be reported by the system.