All Cisco-Network Study Notes: Directory Gatekeepers

Directory Gatekeepers

In a ample network, configuring the prefixes of anniversary area on all of the gatekeepers can be

time consuming. A agenda attendant can be acclimated to abate the agreement accomplish on

nondirectory gatekeepers in a network. LRQ forwarding allows a attendant to be

appointed as a agenda attendant or cool gatekeeper. With this feature, it is alone necessary

to configure anniversary attendant with its own bounded zones and area prefixes, and a single

match-all wildcard prefix for the area of the agenda gatekeeper. Alone the directory

gatekeeper has to be configured with the abounding set of all zones and area prefixes aural the

network.

A agenda attendant is basically a attendant that assiduously LRQ letters to other

gatekeepers, in chase of E.164 resolution, as depicted in Figure 8-27. These LRQ messages

are triggered by added gatekeepers that charge to apperceive how to locate an E.164

address to action a call.

When abacus a agenda attendant to a network, accede these points:

■ Application agenda gatekeepers is a arrangement architecture decision.

■ Bounded zones and LRQ forwarding zones can be mixed.

■ An LRQ from a non-Cisco attendant cannot be forwarded.

Directory Attendant Characteristics

Gatekeepers accumulate clue of added H.323 zones and advanced calls appropriately. When

many H.323 zones are present, attendant agreement can become accelerated in administrative

terms. In ample VoIP installations, you can use a centralized agenda gatekeeper

that contains a anthology of all the altered zones and coordinates LRQ-forwarding

processes. In the case of agenda gatekeepers, you no best charge a full-mesh configuration

between interzone gatekeepers.

Figure 8-27 Agenda Gatekeepers

A agenda attendant is about a cool attendant that assiduously LRQ messages.

LRQ letters are RAS letters triggered by an ARQ bulletin from endpoints that are

forwarded from attendant to gatekeeper. There is a absolute of bristles hops for an LRQ message,

which allows up to a four-tier attendant hierarchy.

By application a agenda gatekeeper, you no best charge a abounding cobweb amid gatekeepers,

which is a above advantage. Agenda gatekeepers accumulate a punch plan and additionally serve as

a abeyant interface to added centralized applications. In a all-embracing Voice over IP (VoIP)

network, a centralized interface point is required. This interface can collaborate with other

applications and agreement suites, such as the Advanced Able Arrangement (AIN) in

Signaling System 7 (SS7), GKTMP avenue servers, and AAA.

Historically, agenda gatekeepers were acclimated alone in ample account provider wholesale

deployments. Nowadays, agenda gatekeepers are additionally acclimated in all-embracing enterprises.

For example, banks with a ample cardinal of Cisco Unified Communications Manager

Express sites can use a agenda attendant to interconnect the Cisco Unified

Communications Manager Express sites with anniversary other.

480 Authorized Self-Study Guide: Cisco Voice over IP (CVOICE)

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