Cisco Unified Contact Center Enterprise Solution Reference ...

IPT: Multi-Site with Centralized Call Processing
2-12
Cisco Unified Contact Center Enterprise 7.x SRND
Chapter 2 Deployment Models
As with the single-site deployment model, all the same options exist when using traditional Unified CCE
configurations. For example, multi-site deployments can run the Unified ICM software all on the same
server or on multiple servers. The Unified ICM software can be installed as redundant or simplex. The
Unified ICM software can be deployed either with the Unified CCE System PG or the Unified CCE PG.
The system can be a System Unified CCE deployment. The number of Cisco Unified CallManager and
Unified IP IVR or Unified CVP servers is not specified by the deployment model, nor are the LAN/WAN
infrastructure, voice gateways, or PSTN connectivity. For other variations, see IPT: Single Site, page
2-6.
Best Practices
VoIP WAN connectivity is required for RTP traffic to agent phones at remote sites.
RTP traffic to agent phones at remote sites may require compression to reduce VoIP WAN bandwidth
usage. It may be desirable for calls within a site to be uncompressed, so transcoding might also be
required depending upon how the Cisco Unified Communications deployment is designed.
Skinny Client Control Protocol (SCCP) call control traffic from IP phones to the Cisco Unified
CallManager cluster flows over the WAN.
CTI data to and from the Unified CCE Agent Desktop flows over the WAN. Adequate bandwidth
and QoS provisioning are critical for these links.
Because there are no voice gateways at the remote sites, customers might be required to dial a
long-distance number to reach what would normally be a local PSTN phone call if voice gateways
with trunks were present at the remote site. This situation could be mitigated if the business
requirements are to dial 1-800 numbers at the central site. An alternative is to offer customers a
toll-free number to dial, and have those calls all routed to the centralized voice gateway location.
However, this requires the call center to incur toll-free charges that could be avoided if customers
had a local PSTN number to dial.
The lack of local voice gateways with local PSTN trunks can also impact access to 911 emergency
services, and this must be managed via the Cisco Unified CallManager dial plan. In most cases, local
trunks are configured to dial out locally and for 911 emergency calls.
Cisco Unified CallManager locations-based call admission control failure will result in a routed call
being disconnected. Therefore, it is important to provision adequate bandwidth to the remote sites.
Also, an appropriately designed QoS WAN is critical.
IVR: Treatment and Queuing with Unified IP IVR
As in the single-site deployment, all call queuing is done on the Unified IP IVR at a single central site.
While calls are queuing, no RTP traffic flows over the WAN. If requeuing is required during a transfer
or reroute on ring-no-answer, the RTP traffic flow during the queue treatment also does not flow over
the WAN. This reduces the amount of WAN bandwidth required to the remote sites.
IVR: Treatment and Queuing with Unified CVP
In this model, Unified CVP is used in the same way as Unified IP IVR.
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