Cisco Unified Contact Center Enterprise Solution Reference ...

Chapter 3 Design Considerations for High Availability
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Data Network Design Considerations
The following sections use Figure 3-1 as the model design to discuss issues and features that you should
consider when designing Unified CCE for high availability. These sections use a bottom-up model (from
a network model perspective, starting with the physical layer first) that divides the design into segments
that can be deployed in separate stages.
Cisco recommends using only duplex (redundant) Cisco Unified CallManager,
Unified IP IVR/Unified CVP, and Unified ICM configurations for all Unified CCE deployments that
require high availability. This chapter assumes that the Unified CCE failover feature is a critical
requirement for all deployments, therefore it presents only deployments that use a redundant (duplex)
configuration, with each Cisco Unified CallManager cluster having at least one publisher and one
subscriber. Additionally, where possible, deployments should follow the best practice of having no
devices, call processing, or CTI Manager Services running on the Cisco Unified CallManager publisher.
Data Network Design Considerations
The Unified CCE design shown in Figure 3-3 starts from a time division multiplexing (TDM) call access
point and ends where the call reaches a Unified CCE agent. The bottom of the network infrastructure in
the design supports the Unified CCE environment for data and voice traffic. The network, including the
PSTN, is the foundation for the Unified CCE solution. If the network is poorly design to handle failures,
then everything in the call center is prone to failure because all the servers and network devices depend
on the network for communication. Therefore, the data and voice networks must be a primary part of
your solution design and must be addressed in the early stages for all Unified CCE implementations.
In addition, the choice of voice gateways for a deployment is critical because some protocols offer more
call resiliency than others. This chapter provides high-level information on how the voice gateways
should be configured for high availability with the Unified CCE solution.
For more information on voice gateways and voice networks in general, refer to the Cisco Unified
Communications Solution Reference Network Design (SRND) guide, available at
http://www.cisco.com/go/srnd
Figure 3-3 High Availability in a Network with Two Voice Gateways and One Cisco Unified CallManager Cluster
Public
network
TDM
access
T1 lines
Voice
Voice
T1 lines gateway 1
gateway 2 Gatekeepers
V
V
IDF
switch 1
IDF
switch 2
Call control, CTI data,
IP messaging
TDM voice lines
Ethernet lines
MDF
switch 1
Cisco CallManager
cluster
Publisher
Sub 1 M Sub 2
M M
MDF
switch 2
Corporate
LAN
Firewall
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Cisco Unified Contact Center Enterprise 7.x SRND
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