Cisco Cisco IP Contact Center Release 4.6.1 Designanleitung

In multi-site environments with distributed voice gateways, Unified CVP can be used to leverage the 
ingress voice gateways at the remote sites as part of the traditional Unified CCE system to provide call 
treatment and queueing at the remote location, using the VoiceXML Browser built into the Cisco IOS 
voice gateway locally. Using the distributed gateways with Unified CVP permits calls to queue locally 
in the ingress voice gateway and rather than requiring the call to cross the VoIP WAN to a centralized 
queue platform. Only call signaling (H.323 and VoiceXML) pass over the WAN to instruct the remote 
site voice gateway how to treat, queue, and transfer the call to an agent. In these models, pre-routing to 
the site might not be necessary because Unified ICM takes control of the call as soon as it arrives at the 
site. Basic carrier percent allocation can be used to allocate calls to the sites and failover (rollover) trunks 
used to address local failures as needed.

Only limited systems management skills are needed for the remote sites because most servers, 
equipment, and system configurations are managed from a centralized location.

The Unified ICM pre-routing option can be used to load-balance calls across sites, including sites 
with local PSTN trunks in addition to toll-free PSTN trunks.

No WAN RTP traffic is required for calls arriving at each remote site that are handled by agents at 
that remote site.

Unified CVP provides call treatment and queueing at the remote site using the VoiceXML Browser 
in Cisco IOS on the voice gateway itself, thus eliminating the need to move the call over the VoIP 
WAN to a central queue and treatment point.

The Unified IP IVR or Unified CVP, Unified CM, and PGs (for both Unified CM and IVR or 
Unified CVP) are co-located. In this model, the only Unified CCE communications that can be 
separated across a WAN are the following:

Unified ICM Central Controller to Unified ICM PG

Unified ICM PG to Unified CCE Agent Desktops

Unified CM to voice gateways

Unified CM to phones

Unified CVP Call Control Server to remote voice gateway (call control)

If calls are not going to be restricted to the site where calls arrive, or if calls will be made between 
sites, more RTP traffic will flow across the WAN. It is important to determine the maximum number 
of calls that will flow between sites or locations. Unified CM locations-based call admission control 
failure will result in a routed call being disconnected (rerouting within Unified CM is not currently 
supported). Therefore, it is important to provision adequate bandwidth to the remote sites, and 
appropriately designed QoS for the WAN is critical.

H.323 or MGCP signaling traffic between the voice gateways and the centralized Unified CM 
servers will flow over the WAN. Proper QoS implementation on the WAN is critical, and signaling 
delays must be within tolerances listed in the latest version of the Cisco Unified Communications 
Solution Reference Network Design (SRND) guide, available at