Panasonic KX-TDA0480 Installation Manual page 14

Planning
• Multipoint Control Unit (MCU)
Gatekeepers
The Gatekeeper is the vital link in an H.323 enabled network. It acts as the central point of
management for all calls within its zone and it provides call control services to all registered
endpoints.
These devices perform several vital functions:
• Gatekeepers are the central points at which LAN identifiers for terminals and gateways
(e.g., telephone numbers) are translated into IP and IPX addresses.
• Gatekeepers can perform bandwidth management tasks that help minimise the impact of
high network loads produced by bandwidth intensive communications.
• Gatekeepers are also capable of providing additional services. For example, they can be
used to balance call loads and to keep billing records for calls placed within their zone.
Gateways
In an H.323 network, the KX-TDA0480 is classified as a Gateway device.
Gateways can provide many different kinds of service but almost all provide translation
services that enable end-point terminals of different types to communicate with one another
seamlessly. TCP/IP network Interfaces are provided for analogue telephone and fax, a digital/
analogue proprietary telephones, PBX, and PSTN networks.
When the KX-TDA0480 is installed in an H.323 network, the unit is in continuous
communication with the H.323 Gatekeeper and uses the call addressing and management
services provided by the Gatekeeper.
In addition, the KX-TDA0480 provides the interface between the worlds of voice and data
communications, performing for example, voice compression/decompression and voice and
fax data packetisation and de-packetisation.
Terminals
At a minimum, H.323 terminals support voice communications, but may also support video
and data. Three other required components are Q.931 for call signalling and call setup,
Registration/Admissions/Status (RAS), which is used for Gatekeeper and Gateway
communications, and support for RTP/RTCP sequencing of audio and video packet data. These
requirements apply to all H.323 devices.
Although the KX-TDA0480 is capable of communicating with other H.323 compliant devices,
the current implementation is intended to communicate with PSTN terminal devices such as;
analogue telephones, PBXs, Key Telephone Systems, and other telephone networking devices.
Multipoint Control Unit (MCU)
MCUs manage the process by which calls involving three or more terminals are setup and
managed. The capabilities may be implemented in stand-alone equipment or may be integrated
into Gateway and/or terminal devices.
Gatekeeper "additional services" vary based upon device manufacturer.
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Installation Manual