Cisco Cisco Unified Contact Center Enterprise 9.0(2) Design Guide

Agents with calls in progress will stay in progress, but with no third-party call control (conference, 
transfer, and so forth) available from their agent desktop softphones. After an agent disconnects 
from all calls, that agent's desktop functionality is restored to the same state prior to failover.

When the Unified CM CTI Manager service on subscriber C recovers, PG side B continues to be 
active and uses the CTI Manager service on Unified CM subscriber D.

Unified CCE can also be overlaid with the Unified CM design model for clustering over the WAN, which 
allows for high availability of Unified CM resources across multiple locations and data center locations. 
There are a number of specific design requirements for Unified CM to support this deployment model, 
and Unified CCE adds its own specific requirements and new failover considerations to the model.

Specific testing has been performed to identify the design requirements and failover scenarios, but no 
code changes were made to the core Unified CCE solution components to support this model. The 
success of this design model relies on specific network configuration and setup, and the network must 
be monitored and maintained. The component failure scenarios noted previously (see 

) are still valid in this model, and the additional failure scenarios for this 

model include:

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Unified CM D

Unified CM B

ICM synchronzation messages
Unified CM intra-cluster messages
JTAPI messages
H323 or MGCP messages
SCCP messages

Unified CM A

Agent PG A

Agent PG B

Unified CM C

CTI Manager

Fails