Cisco Cisco Unified Contact Center Enterprise 9.0(2) Maintenance Manual
Figure 5: Unified ICME Fault-Tolerant Architecture
Each PG, NIC, and Administration & Data Server or Administration Client has duplicate
communication paths to the Central Controller. If there is a failure on one side of the Central
Controller, the PGs, NICs, and Administration & Data Servers or Administration Clients can
switch their communication paths to the active side of the Central Controller. As shown in the
above figure, only one communication path is active at a time. The other communication path
is idle (indicated by a dotted line). The system software sends heartbeats (brief periodic messages)
over the idle path to ensure that it can still be used in the event that the active path fails.
communication paths to the Central Controller. If there is a failure on one side of the Central
Controller, the PGs, NICs, and Administration & Data Servers or Administration Clients can
switch their communication paths to the active side of the Central Controller. As shown in the
above figure, only one communication path is active at a time. The other communication path
is idle (indicated by a dotted line). The system software sends heartbeats (brief periodic messages)
over the idle path to ensure that it can still be used in the event that the active path fails.
Synchronization and State Transfer
In synchronized execution, duplicated processes are always processing identical input and
generating identical output. If one process fails, the other continues to operate without interrupting
generating identical output. If one process fails, the other continues to operate without interrupting
Administration Guide for Cisco Unified ICM/Contact Center Enterprise & Hosted Release 8.x
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Chapter 2: Fault Tolerance
Central Controller