Page 124 - Voice Over IP Basics | Appendix B: Concepts |
Gatekeeper
Terminals are the LAN client endpoints that provide real time two way communications. When an endpoint is switched on, it performs a multicast discovery for a gatekeeper and registers with it. Thus the gatekeeper knows how many users are connected and where they are located. The collection of a gatekeeper and its registered endpoints is called as a zone. A gatekeeper is required to perform the following functions:
•Address translation
Translation of an alias address to a Transport Address using a table updated via Registration messages.
•Admissions control
Authorization of LAN access, using Admissions Requests or Confirm and Reject (ARQ/ARC/ARJ) messages. Access is based on call authorization, bandwidth or some other criteria.
•Bandwidth management
Support for Bandwidth Request, Confirm and Reject messages, or a null function that accepts all requests for bandwidth changes.
•Zone management
The Gatekeeper provides the above functions for terminals, MCUs, and Gateways, which are registered in its Zone of control.
SoftPhone
The term SoftPhone refers to a IP extension, a dedicated LAN attached H323 compliant device, or a Software programme running on a
Page 124 - Appendix B: Concepts | INDeX IPNC Cassette Administration Manual |
Voice Over IP Basics | 38DHB0002UKDD – Issue 7 (22/11/02) |
