Cisco Unified Contact Center Enterprise Solution Reference ...

Designing for High Availability
Figure 3-2 Unified CCE Single-Site Redundancy
Public
network
TDM
access
3-4
T1 lines
T1 lines
Agent 1
PC
IDF
switch 1
VRU
PG A
IP
IP IVR 1
IPCC site side A
Voice
gateway 1
MDF
switch 1
Subscriber 1 M
Subscriber 2
Agent
PG A
CM CTI OS
WedView
Reporting Client
ICM A
Cisco Unified Contact Center Enterprise 7.x SRND
V
Publisher
V
M M
ICM B
IPCC site side B
Voice
gateway 2
MDF
switch 2
Agent
PG B
CM CTI OS
WedView
Reporting Client
Chapter 3 Design Considerations for High Availability
IP IVR 2
IDF
switch 2
VRU
PG B
Agent 2
PC
Call control, CTI data,
IP messaging
TDM voice lines
Ethernet lines
Figure 3-2 emphasizes the redundancy of the single site design in Figure 3-1. Side A and Side B are
basically mirror images of each other. In fact, one of the main Unified CCE features to enhance high
availability is its ability to add redundant/duplex components that are designed to automatically fail-over
and recover without any manual intervention. Core system components with redundant/duplex
components are interconnected to provide failure detection of the “partner” system with the use of TCP
keep-alive messages generated every 100 ms over a dedicated network path. The fault-tolerant design
and failure detection/recovery method is described later in this chapter.
Other components in the solution use other types of redundancy strategies. For example, Cisco Unified
CallManager uses a cluster design to provide IP phones and devices with multiple Cisco Unified
CallManager subscribers (servers) with which to register if the primary server fails, and those devices
automatically re-home to the primary when it is restored.
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143941
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