Cisco Unified Contact Center Enterprise Solution Reference ...

Chapter 3 Design Considerations for High Availability
OL-8669-05
Designing for High Availability
In Figure 3-1, each component in the Unified CCE solution is duplicated with a redundant or duplex
component, with the exception of the intermediate distribution frame (IDF) switch for the Unified CCE
agents and their phones. The IDF switches do not interconnect with each other, but only with the main
distribution frame (MDF) switches, because it is better to distribute the agents among different IDF
switches for load balancing and for geographic separation (for example, different building floors or
different cities). If an IDF switch fails, all calls should be routed to other available agents in a separate
IDF switch or to a Unified IP IVR (Customer Response Solutions (CRS)) queue. Follow the design
recommendations for a single-site deployment as documented in the Cisco Unified Communications
Solution Reference Network Design (SRND) guide, available at
http://www.cisco.com/go/srnd
If designed correctly for high availability and redundancy, a Unified CCE system can lose half of its
systems and still be operational. With this type of design, no matter what happens in the Unified CCE
system, each call can still be handled in one of the following ways:
Routed and answered by an available Unified CCE agent using an IP phone or desktop softphone
Sent to an available Unified IP IVR (CRS) or Unified CVP port or session
Answered by the Cisco Unified CallManager AutoAttendant
Prompted by a Unified IP IVR (CRS) or Unified CVP announcement that the call center is currently
experiencing technical difficulties, and to call back later
Rerouted to another site with available agents or resources to handle the call
The components in Figure 3-1 can be rearranged to form two connected Unified CCE sites, as illustrated
in Figure 3-2.
Cisco Unified Contact Center Enterprise 7.x SRND
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