Clustering over the IP WAN Deployment
Cisco supports Cisco UCM clusters over a WAN, as illustrated in Figure 1-28. Clustering
over the WAN involves having the applications and UCM of the same cluster distributed
across the IP WAN.
48 Authorized Self-Study Guide: Cisco Voice over IP (CVOICE)
V
IP
WAN
<40 ms Round-Trip Delay
QoS-Enabled BW
V
SIP/SCCP SIP/SCCP
Publisher/TFTP
Server
Figure 1-28 Clustering over the IP WAN
Clustering over the WAN can support two types of deployments:
■ Local Failover Deployment Model: Local failover requires that you place UCM subscriber
and backup servers at the same site, with no WAN between them. This
deployment model is ideal for two to four sites with UCM.
■ Remote Failover Deployment Model: Remote failover allows you to deploy the
backup servers over the WAN. Using this deployment model, you might have up to
eight sites with UCM subscribers being backed up by UCM subscribers at another
site.
Note The remote failover deployment model might need higher bandwidth because a
large amount of intracluster traffic flows between the subscriber servers.
You can also use a combination of the two deployment models to satisfy specific site
requirements. For example, two main sites might each have primary and backup subscribers,
with another two sites containing only a primary server each and utilizing either
shared backups or dedicated backups at the two main sites.