The Role and Configuration of a Cisco
CallManager and Gatekeeper
By implementing H.323 gatekeepers for admission control, you will be able to
control the number of calls allowed to and from specific areas.This will assist you
in the management of bandwidth and resources for your sites and overall infrastructure.
The Cisco CallManager uses the gatekeeper to perform admission control,
especially in infrastructures that use hub and spoke architecture for network
centralization.
www.syngress.com
316 Chapter 9 • AVVID Dial Plans
The gatekeeper will also assist with address resolution.The Cisco
CallManager will know what ranges of extensions are within its control and is
able to route the calls to the proper destination. If the extension is not local to
the Cisco CallManager, it goes to the gatekeeper for the address of another Cisco
CallManager that can direct the call to its destination (hopefully).
The reason this occurs is because each Cisco CallManager registers itself with
the gatekeeper, which is configured with the address range of each Cisco
CallManager (or cluster).This helps hold the dial plans each Cisco CallManager
will need to set up.There are three types of dial plan deployment models for destination
resolution of calls from within the cluster.They are:
The Cisco CallManager Model
The Gatekeeper Model
The Hybrid Model