Cisco Unified Contact Center Enterprise Solution Reference ...

Cluster Guidelines and Considerations
10-6
Cisco Unified Contact Center Enterprise 7.x SRND
Chapter 10 Sizing Cisco Unified CallManager 4.x and 5.x Servers
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
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. While it is possible to support up to 2000 agents via a single CTI Manager (and, thus, a
single IPCC Peripheral Gateway), any deployment with over 1000 agents per CTI Manager and
IPCC Peripheral Gateway requires prior approval from Cisco Bid Assurance. For additional CTI
Manager best practices, refer to the Cisco Unified Communications Solution Reference Network
Design (SRND), available at
www.cisco.com/go/srnd
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 Cisco Unified CallManager servers, and all general office IP phones
and their associated devices (such as gateway ports) would be on other Cisco Unified CallManager
servers, as long as cluster capacity allows. You have to run the Cisco Unified CallManager Capacity
Tool multiple times with the specific device configuration for each primary Cisco Unified
CallManager 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 Cisco Unified CallManager
Redundancy, page 10-8, for details.)
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
Cisco Unified CallManager cluster.
All CTI route points associated with the IPCC Peripheral Gateway (PG) JTAPI user should be
configured to register with the subscriber node running the CTI Manager instance that is
communicating with that IPCC PG.
The Cisco Unified CallManager Capacity Tool does not currently measure CTI Manager impact on
each server separately. However, CTI Manager does place an additional burden on the subscriber
node running that process. Therefore, for large deployments, Cisco recommends configuring
slightly fewer agents and BHCA on that server (compared with the other servers in the cluster). The
goal is to distribute call processing across all servers as evenly as possible.
Devices that are associated with an ICM PG JTAPI user but are not used by a call center agent,
should still be counted as an agent device because the PG will still be notified of all device state
changes for that phone even though it is not being used by an agent. If a device is unlikely to be used
regularly by a call center agent, Cisco recommends that you do not associate the device with the
ICM PG JTAPI user in order to increase cluster scalability.
For deployments requiring large numbers of IVR ports, Cisco recommends using CVP instead of
IP IVR. IP IVR ports place significant call processing burden on Cisco Unified CallManager, while
CVP does not. Thus, Unified CCE deployments with CVP will allow more agents and higher BHCA
rates per cluster. All deployments should be sized using the Cisco Unified CallManager Capacity
Tool.
Note System IPCC does not support CVP at this time.
OL-8669-05