ITU-T’s (International Telecommunications Union) standard – vendors need to comply to supply VoIP.
Encompasses point to point communications & multipoint conferences.
Consists of four components:
- Terminals
- Endpoint host systems providing real time, two way comms.
- Can communicate with another H.323 terminal, H.323 gateway or MCU.
- Gateways
- Endpoint providing communication between terminal or another gateway.
- Translates transmission formats e.g audio an dvideo codes.
- Interface between network & Internet.
- Gatekeepers
- Central point
- Manages calls within it’s zone.
- Translates alias address to transport address, grants/denies access based on call authorisation, source or destination address or other criteria.
- Supports bandwidth and call management
- MCUs (Multipoint Control Units)
- Provides capability for three or more terminals & gateways to participate in multipoint conference by multiplexing audio, video and data.