Cisco Cisco IP Contact Center Release 4.6.1 Design Guide

The Unified Outbound Option option provides high availability through multiple dialers per Unified CM 
cluster. Calls are distributed evenly among the dialers. If a dialer fails, the calls are re-routed to the other 
dialers throughout the enterprise that are configured to support the remaining campaign contacts. The 
calls that were in progress on the failed dialer are marked for retry.

The Campaign Manager and Import process components of the Unified Outbound Option are simplex 
components and are required to be co-located with the Logger (Side A).

In a System Unified CCE deployment model, configuration support is currently provided for one dialer 
for the single PG. If more dialers are required, then the System PG or Enterprise deployment models are 
recommended.

It is normal practice to set up Unified IP phones to be able to fail over to another Unified CM in case of 
a Unified CM node failure in which phones are distributed across the cluster. The Dialer is not a normal 
phone, and the ports for a dialer should not be distributed across multiple nodes within the cluster. 

Give careful consideration before configuring a dialer to fail-over to a back up subscriber. The dialer can 
tax the Unified CM node when starting a campaign or whenever resources are available (agents or IVR 
ports for transfer to IVR campaign). If two dialers are configured to share the Unified CM as part of 
distribution or node failure, a high-availability attempt can have a negative performance impact on the 
rest of the system. Each dialer has its own port throttling mechanism, and is not aware that another dialer 
may be sharing the same Unified CM. With two dialers competing, the subscriber might enter into a code 
yellow condition. However, the dialer can fail over to a back up subscriber provided that the subscriber 
is completely idle and allocated for back up activities only. 

The general rule in configuring the dialers for high availability is to do no harm. As part of this guideline, 
be aware that dialers significantly affect Unified CM performance, and therefore it is advisable to 
validate the deployment design by running the resource calculators available (with appropriate login 
authentication) at 

.

Mobiles agents are supported for outbound campaigns. However, only a nailed-up connection is 
supported. For more details regarding Cisco Unified Mobile Agent, see the chapter on 

.

For more information on the Unified Outbound Option feature, refer to the Cisco Unified Outbound 
Option documentation available at