Cisco Cisco IP Contact Center Release 4.6.2 Merkblatt

server would support a maximum of 1,000 agents. These capacities can vary, depending on your 
specific deployment. All deployments must be sized by using the Cisco Unified CM Capacity Tool 
or the Unified Communications Sizing Tool.

Devices (including phones, music on hold, route points, gateway ports, CTI ports, JTAPI Users, and 
CTI Manager) should never reside or be registered on the publisher. Any administrative work on 
Unified CM will impact call processing and CTI Manager activities if there are any devices 
registered with the publisher.

Do not use a publisher as a failover or backup call processing server unless you have fewer than 100 
or 150 agent phones and the installation is not mission critical or is not a production environment. 
The Cisco MCS-7825 server is the minimum server supported for Unified CCE deployments. (Refer 
to 

 for more details.) Any deviations will require review by Cisco Bid Assurance on a 

case-by-case basis.

Any deployment with more than 150 agent phones requires a minimum of two subscriber servers 
and a combined TFTP and publisher. The load-balancing option is not available when the publisher 
is a backup call processing subscriber.

If you require more than one primary subscriber to support your configuration, then distribute all 
agents equally among the subscriber nodes. This configuration assumes that the BHCA is uniform 
across all agents.

Similarly, distribute all gateway ports and Unified IP IVR CTI ports equally among the cluster 
nodes.

If you require more than one Unified ICM JTAPI user (CTI Manager) and more than one primary 
Unified CM subscriber, then group and configure all devices monitored by the same Unified ICM 
JTAPI User (third-party application provider), such as Unified ICM route points and agent devices, 
on the same server if possible.

CTI Manager should be enabled only on call processing subscribers, thus allowing for a maximum 
of eight CTI Managers in a cluster. To provide maximum resilience, performance, and redundancy, 
Cisco recommends that you load-balance CTI applications across the various CTI Managers in the 
cluster. For additional CTI Manager best practices, refer to the Cisco Unified Communications 
Solution Reference Network Design (SRND), available at

If you have a mixed cluster with Unified CCE and general office IP phones, group and configure 
each type on a separate server if possible (unless you need only one subscriber server). For example, 
all Unified CCE agents and their associated devices and resources (gateway ports, CTI ports, and so 
forth) would be on one or more Unified CM servers, and all general office IP phones and their 
associated devices (such as gateway ports) would be on other Unified CM servers, as long as cluster 
capacity allows. If you use the Cisco Unified CM Capacity Tool, you have to run it multiple times 
with the specific device configuration for each primary Unified CM server because the tool assumes 
all devices are equally balanced in a cluster. In this case, Cisco strongly recommends the 1:1 
redundancy scheme. (See 

, for details.) If you use the Unified 

Communications Sizing Tool instead, you do not have to run it multiple times because this tool 
supports deployments with dedicated Unified CM servers for agent phones or with a mixed cluster.

Cisco recommends that you use hardware-based conference resources whenever possible. Hardware 
conference resources provide a more cost-effective solution and allow better scalability within a 
Unified CM cluster.

All CTI route points associated with the Unified CCE Peripheral Gateway (PG) JTAPI user should 
be configured to register with the subscriber node running the CTI Manager instance that is 
communicating with that Unified CCE PG.