Cisco Unified Contact Center Enterprise Solution Reference ...

Cisco Unified CallManager and CTI Manager Design Considerations
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Cisco Unified Contact Center Enterprise 7.x SRND
Chapter 3 Design Considerations for High Availability
client library in Cisco CallManager Release 3.3(x) and above connects to the CTI Manager instead of
connecting directly to the Cisco Unified CallManager service directly, as in prior releases. In addition,
there can be multiple CTI Manager services running on different Cisco Unified CallManager servers in
the cluster that are aware of each other (via the Cisco Unified CallManager service, which is explained
later in this section). The CTI Manager uses the same Signal Distribution Layer (SDL) signaling
mechanism that the Cisco Unified CallManager services in the cluster use to communicate with each
other. However, the CTI Manager does not directly communicate with the other CTI Managers in its
cluster. (This is also explained later in detail.)
The main function of the Cisco Unified CallManager service is to register and monitor all the
Cisco Unified Communications devices. It basically acts as a switch for all the Cisco Unified
Communications resources and devices in the system, while the CTI Manager service acts as a router for
all the CTI application requests for the system devices. Some of the devices that can be controlled by
JTAPI that register with the Cisco Unified CallManager service include the IP phones, CTI ports, and
CTI route points.
Figure 3-4 illustrates some of the functions of Cisco Unified CallManager and the CTI Manager.
Figure 3-4 Functions of Cisco Unified CallManager and the CTI Manager
Agent
PG
V
JTAPI
MGCP
H.323
Subscriber
(CTI Manager
and
Cisco
CallManager)
Publisher
(CTI Manager
and
CallManager)
SDL
M
SDL
M M
Skinny client control
protocol (SCCP)
Subscriber
(CTI Manager
and
Cisco
CallManager)
IP IP IP IP IP IP
JTAPI
SCCP
The servers in a Cisco Unified CallManager cluster communicate with each other using the Signal
Distribution Layer (SDL) service. SDL signaling is used only by the Cisco Unified CallManager service
to talk to the other Cisco Unified CallManager services to make sure everything is in sync within the
Cisco Unified CallManager cluster. The CTI Managers in the cluster are completely independent and do
not establish a direct connection with each other. CTI Managers route only the external CTI application
requests to the appropriate devices serviced by the local Cisco Unified CallManager service on this
subscriber. If the device is not resident on its local Cisco Unified CallManager subscriber, then the
Cisco Unified CallManager service forwards the application request to the appropriate Cisco Unified
CallManager in the cluster. Figure 3-5 shows the flow of a device request to another Cisco Unified
CallManager in the cluster.
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