Cisco Unified Contact Center Enterprise Solution Reference ...

Chapter 2 Deployment Models
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IPT: Multi-Site with Distributed Call Processing
Best Practices
The Unified CCE Gateway PG, Cisco Unified CallManager cluster, Unified IP IVR, and System
Unified CCE must be co-located at the contact center site.
The communication link from the parent Unified ICM Central Controller to the Unified CCE
Gateway PG must be sized properly and provisioned for bandwidth and QoS. (For details, refer to
the chapter on Bandwidth Provisioning and QoS Considerations, page 11-1.)
Gatekeeper-based call admission control could be used to reroute calls between sites over the PSTN
when WAN bandwidth is not available. It is best to ensure that adequate WAN bandwidth exists
between sites for the maximum amount of calling that can occur.
If the communication link between the Unified CCE Gateway PG and the parent Unified ICM
Central Controller is lost, then all contact center routing for calls at that site is put under control of
the local System Unified CCE. Unified CVP-controlled ingress voice gateways would have
survivability TCL scripts to redirect inbound calls to local Cisco Unified CallManager CTI route
points, and the local Unified IP IVR would be used to handle local queue and treatment during the
WAN outage. This is a major feature of the parent/child model to provide complete local
survivability for the call center. For more information, see the chapter on Design Considerations for
High Availability, page 3-1.
While two intercluster call legs for the same call will not cause unnecessary RTP streams, two
separate call signaling control paths will remain intact between the two clusters (producing logical
hairpinning and reducing the number of intercluster trunks by two).
Latency between parent Unified ICM Central Controllers and remote Unified CCE Gateway PGs
cannot exceed 200 ms one way (400 ms round-trip).
IVR: Distributed Voice Gateways with Treatment and Queuing Using
Unified CVP
This deployment model is the same as the previous model, except that Unified CVP is used instead of
Unified IP IVR for call treatment and queuing. In this model, voice gateways with PSTN trunks
terminate into each site. Just as in the centralized call processing model with distributed voice gateways,
it might be desirable to limit the routing of calls to agents within the site where the call arrived (to reduce
WAN bandwidth). Call treatment and queuing can also be achieved at the site where the call arrived,
further reducing the WAN bandwidth needs. Figure 2-6 illustrates this model using traditional Unified
CCE deployment.
Cisco Unified Contact Center Enterprise 7.x SRND
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