MGC Administrator’s Guide
E-7
When one endpoint calls another endpoint using only its alias, the gatekeeper
is queried for the IP address of the destination endpoint. In addition, the
destination endpoint requests the permission to use the required bandwidth.
When the call ends, both endpoints send a notification to the gatekeeper,
which in turn releases the bandwidth to other uses.
To perform these two main functions, the gatekeeper collects and maintains
information about the conferencing activity on the network. This information
is also used for other gatekeeper functions, such as, routing, monitoring,
billing, and more.
The gatekeeper can be incorporated in the MCU, or it can be an external,
separate device. The MGC unit works with an external gatekeeper. Each zone
on the LAN includes only one gatekeeper.
H.323 Endpoints
H.323 endpoints must support voice communications. Video and data are
optional. H.323 endpoints must also support:
•
RAS (Registration Admission Status), which is a signaling protocol used
to communicate between endpoints and the gatekeeper
•
Q.931 for call signaling and call setup
•
H.245 for session control to negotiate media capabilities and logical
channel usage
•
RTP/RTCP for delivery and control of audio and video streams
SIP Endpoints (User Agents)
SIP enabled end-devices, are usually application programs that send SIP
requests, such as a PC with headset attachment or SIP phone. User Agents
(UA) must be capable of establishing and terminating a media session with
another User Agent. UAs should be capable of supporting both UDP and TCP
H.323
SIP
Required
N/A
H.323
SIP
N/A
Required
Содержание MGC Administrator
Страница 1: ...MGC Administrator s Guide Version 7 5 ...
Страница 4: ......
Страница 50: ...Chapter 2 Software Installation 2 32 ...
Страница 408: ...Chapter 6 Defining Operators 6 12 ...
Страница 482: ...Chapter 7 Configuring the Gateway 7 74 ...
Страница 496: ...Chapter 8 Audio and Video Conversion Tools 8 14 ...
Страница 534: ...Appendix B PPP Setup B 24 ...