Dialogic Global Call IP Benutzerhandbuch

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Dialogic Corporation

The H.323 specification defines the entity types in an H.323 network including:

Terminal

An endpoint on an IP network that supports the real-time, two-way communication with 
another H.323 entity. A terminal supports multimedia coders/decoders (codecs) and setup and 
control signaling.

Gateway

Provides the interface between a packet-based network (for example, an IP network) and a 
circuit-switched network (for example, the PSTN). A gateway translates communication 
procedures and formats between networks. It handles call setup and teardown and the 
compression and packetization of voice information.

Gatekeeper

Manages a collection of H.323 entities in an H.323 zone controlling access to the network for 
H.323 terminals, Gateways, and MCUs and providing address translation. A zone can span a 
wide geographical area and include multiple networks connected by routers and switches. 
Typically there is only one gatekeeper per zone, but there may be an alternate gatekeeper for 
backup and load balancing. Typically, endpoints such as terminals, gateways, and other 
gatekeepers register with the gatekeeper.

Multipoint Control Unit (MCU)

An endpoint that supports conferences between three or more endpoints. An MCU can be a 
stand-alone unit or integrated into a terminal, gateway, or gatekeeper. An MCU consists of:

Multipoint Controller (MC) – handles control and signaling for conferencing support

Multipoint Processor (MP) – receives streams from endpoints, processes them, and 
returns them to the endpoints in the conference

Figure 1 shows the entities in a typical H.323 network.

PSTN

Internet or

Intranet

Gateway

Router

Gatekeeper

MCU

Terminal

Terminal

Terminal

LAN