Information Technology Reference
In-Depth Information
redundancy, and Unity servers are used for messaging. Intercluster trucks are created to
establish communication between clusters. IP phones are deployed on PoE LAN switches.
CUCM Cluster B
Unity: Voice Mail
CUCM Cluster A
Unity: Voice Mail
WAN
Router with
PSTN
V
WAN
Site B
V
Unity: Voice Mail
CUCM Cluster C
WAN
Router with
PSTN
Gateway
PSTN
V
WAN
Router with
PSTN
Site C
Figure 14-12
Multisite WAN with Distributed CM Deployment Model
This model also supports remote sites to be distributed off the large sites. Cisco gatekeep-
ers (special software feature on IOS routers) can be deployed to support a unified dial
plan and enforce CAC.
Unified CallManager Express Deployments
Cisco provides express versions of its CallManager and Unity solutions integrated in its
Integrated Services Routers (ISR). CallManager Express (CME) provides the call process-
ing capabilities on a router. Unity Express provides voice-mail and auto-attendant func-
tions on special modules that can be installed in a router. CME deployments support up
to 450 Cisco IP phones (hardware dependent, based on 3945 ISR G2). It is a distributed,
lower-cost solution for small branch offices.
Video Deployment Considerations
There has been an increase in the amount of video over IP traffic on data networks. In the
workplace, the use of desktop video conferencing, video broadcasts, IP video surveillance
are increasingly being seen on the network. Video surveillance requires high bandwidth
