RADVision L2W-323, User Manual

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Overview
2-16
Understanding the Internal Gatekeeper
The L2W-323 operates together with an H.323 gatekeeper. The gatekeeper provides the
required address translation, admission control and bandwidth control, it supplies optional
directory services and PBX functions and H.323 bandwidth management, and it allows the
system administrator to specify administration and security policies for the H.323 network.
The L2W-323 Gateway has an internal Gatekeeper that can be enabled or disabled. When
disabled, you have to define an alternative gatekeeper for the L2W-323 Gateway that can be
one of the following:
!"
An internal RADVision Gatekeeper in another RADVision unit.
!"
A RADVision Gatekeeper, the NGK-100.
!"
Another H.323 gatekeeper.
Although the L2W-323 Gateway functions with other H.323 gatekeepers, the RADVision
Gatekeepers work seamlessly with the Gateway and offer many value-added functions. The
following section describes the internal Gatekeeper in detail.
How the RADVision Gatekeeper Works
The RADVision Gatekeeper functions as an overall network administrator and provides the
necessary address translation enabling LAN endpoints to communicate with each other and
with the other H.323 components on the network. The Gatekeeper also enables outbound
communication with terminals and phones on the ISDN public network.
Note: All references made to the RADVision Gatekeeper relate to the internal gatekeeper.
If you are working with a RADVision NGK-100 Gatekeeper or a third-party
gatekeeper, refer to their documentation for information on how to operate these
products.
For the Gatekeeper to be able to manage H.323 endpoints, these endpoints have to register
with the Gatekeeper. This occurs when the Gatekeeper is defined as the default Gatekeeper
for an endpoint. All endpoints with a common default Gatekeeper comprise a Gatekeeper
zone. Several Gatekeepers can operate on the same network but only one Gatekeeper can be
active per zone. In other words, each endpoint must have one and only one default
Gatekeeper.
When an endpoint registers with the Gatekeeper, endpoint properties are stored in a
database. Endpoint properties include identification properties such as an IP address,
aliases
and supported services.