Cisco Cisco Customer Voice Portal 8.0(1)

If a call is received for 800-555-0020 through 0029, Gateway Dewey will first perform a DNS lookup 
on the Domain Name “Customer Voice Portal_2@cisco.com.” In this example, the DNS will map this 
domain name to 10.10.10.21 and 10.10.10.22, which will cause Dewey to route the call to a Voice 
Browser in Customer Voice Portal_2. However, if Customer Voice Portal_2 does not respond properly, 
Dewey will then perform a DNS lookup on the Domain Name “Customer Voice 
Portal2_backups@cisco.com.” In this example, the DNS will map this domain name to 10.10.10.11 and 
10.10.10.31, which will cause Dewey to route the call to a Voice Browser in Customer Voice Portal_1 or 
a VB in Customer Voice Portal_3.

When a Gatekeeper is present, Inbound call routing to the Customer Voice Portal is controlled by 
information kept at one or more H.323 Gatekeepers. H.323 enforces the concept of zones, where a single 
logical Gatekeeper (which may be one or more actual Gatekeepers) is responsible for routing control 
within its zone. 

For ease of illustration, we will initially assume that all the Customer Voice Portal nodes reside within 
the same H.323 zone, the “Customer Voice Portal Zone.” 

 shows the Customer Voice Portal nodes and Gateways separated into three different H.323 

zones:

Customer Voice Portal_1 and GW Huey are assigned to Zone 1, which is controlled by GK_1.

Customer Voice Portal_2 and GW Dewey are assigned to Zone 2, which is controlled by GK_2.

Customer Voice Portal_3 and GW Louie are assigned to Zone 3, which is controlled by GK_3. 

Each Customer Voice Portal node contains three Voice Browsers, with the IP addresses shown. As with 
the 

 section, it is assumed that each of the Voice Browsers have registered with its 

Gatekeeper, and that the Gateways are configured—for details, see 

—to perform RAS lookups in their Gatekeeper for incoming calls.