About H.323; Using The Vcs As An H.323 Gatekeeper; H.323 Endpoint Registration; H.323 Configuration - Cisco TelePresence Administrator's Manual

About H.323

The VCS supports the H.323 protocol: it is an H.323 gatekeeper.
It will also provide interworking
endpoints that only support one of these protocols to call each other. In order to support H.323, the H.323
mode must be enabled.

Using the VCS as an H.323 gatekeeper

As an H.323 gatekeeper, the VCS accepts registrations from H.323 endpoints and provides call control
functions such as address translation and admission control.
To enable the VCS as an H.323 Gatekeeper, you must ensure that H.323 mode is set to On
configuration > Protocols >
Note that this is the default setting, so the VCS will work as an H.323 gatekeeper "out of the box", without
any other special configuration.

H.323 endpoint registration

H.323 endpoints in your network must register with the VCS in order to use it as their gatekeeper.
There are two ways an H.323 endpoint can locate a VCS with which to register: manually or automatically.
The option is configured on the endpoint itself under the Gatekeeper Discovery setting (consult your endpoint
manual for how to access this setting).
If the mode is set to automatic, the endpoint will try to register with any VCS it can find. It does this by
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sending out a Gatekeeper Discovery Request, to which eligible VCSs will respond.
If the mode is set to manual, you must specify the IP address of the VCS with which you want your
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endpoint to register, and the endpoint will attempt to register with that VCS only.
Preventing automatic H.323 registrations
You can prevent H.323 endpoints being able to register automatically with the VCS by disabling Auto
Discovery on the VCS (VCS configuration > Protocols >

H.323 configuration

The H.323 page (VCS configuration > Protocols >
VCS, including:
whether H.323 is enabled or not
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H.323 gatekeeper settings
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whether to insert the prefix of the ISDN gateway into the caller's E.164 number presented on the
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destination endpoint
The configurable options are:
Cisco VCS Administrator Guide (X7.2)
between H.323 and SIP, translating between the two protocols to enable
H.323).
H.323) is used to configure the
H.323).
H.323
Protocols
(VCS
settings on the
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