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

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Cisco Unified Contact Center Enterprise 7.0, 7.1, and 7.2 SRND
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Chapter 3      Design Considerations for High Availability
Peripheral Gateway Design Considerations
Figure 3-19
Scenario 3 – Only the Primary Unified CM Subscriber Fails
Scenario 4: Only the Unified CM CTI Manager Service Fails
 shows a CTI Manager service failure on Unified CM subscriber C. The CTI Manager 
services are running on Unified CM subscribers C and D, and Unified CM subscriber C is the active CTI 
Manager connected to the Unified CCE Peripheral Gateway side A. However, all phones and gateways 
are registered with Unified CM subscriber A. During this failure, both the CTI Manager and the PG 
fail-over to their secondary sides. Because the JTAPI service on PG side B is already logged into the 
secondary (now primary) CTI Manager, the device registration and initialization time is significantly 
shorter than if the JTAPI service on PG side B had to log into the CTI Manager.
The following conditions apply to this scenario:
  •
All phones and gateways are registered with Unified CM subscriber A.
  •
All phones and gateways are configured to re-home to Unified CM subscriber B (that is, B is the 
backup server).
  •
Unified CM subscribers C and D are each running a local instance of CTI Manager.
  •
If the Unified CM CTI Manager service on subscriber C fails, the PG side A detects a failure of the 
CTI Manager service and induces a failover to PG side B.
  •
PG side B registers all dialed numbers and phones with the Unified CM CTI Manager service on 
subscriber D, and call processing continues.
M
M
M
M
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Unified CM D
Unified CM C
Unified CM B
Unified CM A
Fails
ICM synchronzation messages
Unified CM intra-cluster messages
JTAPI messages
H323 or MGCP messages
SCCP messages
Agent PG A
Agent PG B
IP