The gatekeeper is the core management entity in an H.323 environment. It is, among other things, responsible for access control, address resolution and H.323 network (load) management and provides the central hook to implement any kind of utilisation / access policies.An H.323 environment is subdivided into zones (which may, but need not be congruent with the underlying network topology); each zone is controlled by one primary gatekeeper (with
optional backup gatekeepers). Gatekeepers may also provide added value, e.g., act as a conferencing bridge or offer supplementary call services.An H.323 Gatekeeper can also be equipped with the proxy feature. Such a feature enables the routing through the gatekeeper of the RTP traffic (audio and video) and the T.120 traffic (data), so no traffic is directly exchanged between endpoints. (It could be considered a kind of IP-to-IP gateway that can be used for
security and QoS purposes); |