Maintenance Manual

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Cisco ICM Enterprise Edition Administrator Guide Release 6.0(0)
Chapter 2 Fault Tolerance
Central Controller
Figure 2-3 Central Controller Failure Scenarios
Each of these failures affects system functions differently:
• Single Logger. If a single Logger goes off-line, ICM software runs without
interruption. All call routing and reporting functions remain available. The
CallRouters continue to operate as a synchronized pair. The remaining
Logger runs simplexed. When the failed Logger returns to service, the
Loggers return to synchronized execution.
• Single CallRouter. When a CallRouter on one side of the Central Controller
fails, that entire side of the Central Controller is removed from service. This
is because the CallRouter plays an integral part in forwarding historical data
to the Logger on its side of the system. The on-line side of the Central
Controller runs as a simplexed system. Call processing continues
uninterrupted and reporting functions are still available. When the failed
CallRouter returns to service, both CallRouters and both Loggers return to
synchronized execution.
• Logger and CallRouter (opposite sides). In this failure scenario, side B of
the Central Controller is removed from service due to the CallRouter failure.
Call routing continues uninterrupted with the remaining Side A CallRouter;
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