HP 480-0005-00-15 - Manual (Page 23)

P/N 480-0005-00-15 1-12
Chapter 1: Overview
In addition, if you are using more than one CMS unit, you can configure one of the border elements for that
zone. The Tenor CMS unit provides two border elements: primary and secondary. These work together as one
entity to provide redundancy and fault tolerance; there are no hierarchical differences.
Call Services
Gatekeepers provide services such as addressing, authorization and authentication of terminals and gateways,
bandwidth management, accounting, billing, and charging. Gatekeepers also provide call-routing services.
Specifically, the Tenor CMS Gatekeeper provides the functions which follow:
Address Translation. The gatekeeper translates telephone numbers into IP addresses and vice versa. It per-
forms Alias Address (phone number) to Transport Address (IP address) translation when an endpoint requests
service. The Gatekeeper uses a translation table to translate an Alias Address (an address such as an H.323
identifier that a user may not understand) to a transport address. The translation table is updated using Regis-
tration messages.
Autodiscovery. The gatekeeper is discovered in one of the following ways: An endpoint sends an IP broad-
cast called a Gatekeeper Request message (GRQ) message (which includes that correct gatekeeper name) to
discover a Gatekeeper OR the endpoint will discover a gatekeeper by its IP address.
Routing. The gatekeeper identifies the IP address of endpoints in its administrative domain. The gatekeeper
builds a routing database from information obtained from the border element and also from gateways and
H.323 endpoints.
Admissions Control. All H.323 endpoints must register and request permission to enter the gatekeeper’s
zone; the gatekeeper will confirm or deny access to the network. The gatekeeper authorizes network access
and protects the integrity of the network using Admissions Request (ARQ), Admissions Confirmation (ACF)
and Admissions Reject (ARJ) messages.
Configuration
For the Gatekeeper/Border Element functionality, the following items are configurable via Command Line
Interface (CLI):
• Primary Border Element IP Address. The IP address for the administrative domain’s Border Element
(the Border Element is internal to the Tenor CMS unit; it is used to establish relationships with other
Border Element
Gatekeeper
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