Configuring H.323 Gatekeepers
In this section, you will apprentice how to configure basal attendant functionality. You will
learn how to configure gatekeepers and Cisco Unified Communications Manager to operate
together. You will additionally apprentice how to configure gateways to annals with a gatekeeper.
Gatekeeper Agreement Steps
Following are the basal accomplish all-important to configure a Cisco IOS attendant and gateway:
Step 1. Configure bounded and alien zones on the gatekeeper.
Step 2. Configure area prefixes for all zones area calls should be routed.
Step 3. Configure technology prefixes to accommodate added adaptability in alarm routing.
Step 4. Configure gateways to use H.323 gatekeepers.
Step 5. Configure punch peers.
Figure 8-32 shows a accepted cartography area a distinct accessory (which in this book is a
gatekeeper) manages assorted zones. Only one attendant can ascendancy a area at any time.
The San Jose aperture is registered with the attendant in the San Jose zone, and the
Houston aperture is registered in the Houston area with the Houston gatekeeper. The
gatekeeper is amenable for alarm resolution, Alarm Admission Ascendancy (CAC), and other
features ahead declared in this chapter. After the alarm setup, the IP phones (which in
this case are Phone1-1 and Phone2-2) are anon connected.
Chapter 8: Configuring H.323 Gatekeepers 489
San Jose
Gatekeeper
Houston
(H.323)
SanJose
(H.323)
Houston
Phone2-1
3001
Phone2-2
3002
Phone1-1
2001
Phone1-2
2002
WAN
Figure 8-32 Distinct Gatekeeper—Multizone Agreement Scenario
Gateway Alternative Process
The attendant maintains a abstracted aperture list, ordered by priority, for anniversary of its zone
prefixes. If a aperture does not accept an assigned antecedence for a area prefix, it defaults to
priority 5, which is the median. To absolutely bar the use of a aperture for a area prefix,
the aperture charge be authentic as accepting a antecedence 0 for that area prefix.
When selecting gateways, the attendant identifies a ambition basin of gateways by performing
a longest area prefix match. Then it selects from the ambition basin according to priorities
and ability availability. If all acute gateways are busy, a low-priority gateway
might be selected.
Cisco H.323 adaptation 2 software improves the aperture alternative action as follows:
■ Back added than one aperture is registered in a zone, the adapted area prefix command
allows alternative priorities to be assigned to these gateways on the base of the
dialed prefix.
■ Aperture ability advertisement allows the aperture to acquaint the attendant back H.323
resources are accepting low. The attendant uses this advice to actuate which
gateway to use to complete a call.
Configuration Considerations
When configuring a gatekeeper, accumulate the afterward in mind:
■ Assorted bounded zones can be defined. The attendant manages all configured local
zones. Intrazone behavior is amid the attendant and the endpoints and gateways
within a specific zone. A attendant can abutment added than one zone. Even though
there is a distinct attendant per bounded zone, the communications amid zones are
considered to be interzone. So, the aforementioned attendant can abutment both intrazone and
interzone communications.
■ Only one RAS IP altercation can be authentic for all bounded zones. You cannot configure
each area to use a altered RAS IP address. If you ascertain this IP abode in the first
zone definition, you can omit it for all consecutive zones that automatically aces up
this address. If you set it in a consecutive area bounded command, it additionally changes the
RAS IP abode of all ahead configured bounded zones. After the IP abode is
defined, you can change it by reissuing any area bounded command with a different
RAS IP address.
■ You cannot abolish a bounded area if there are endpoints or gateways registered in it. To
remove the bounded zone, aboriginal shut bottomward the gatekeeper, which armament the endpoints,
gateways, and the bounded area to unregister.
■ Assorted analytic gatekeepers ascendancy the assorted zones on the aforementioned Cisco IOS
platform.
■ The best cardinal of bounded zones authentic in a attendant should not beat 100.
Basic Attendant Agreement Commands
Table 8-2 shows basal attendant agreement commands.
Table 8-2 Basal Attendant Agreement Commands
Command Purpose
Gatekeeper Enters attendant agreement mode.
zone bounded gatekeeper-name Specifies a area controlled by a gatekeeper.
domain-name [ras-ip-address] ■ gatekeeper-name: Specifies the area name. This is usually
[invia inbound_gatekeeper | the absolutely able area name of the gatekeeper.
outvia outbound_gatekeeper ■ domain-name: Specifies the area name served by this
[enable-intrazone]] gatekeeper.
■ ras-ip-address: (Optional) Specifies the IP abode of one
of the interfaces on the gatekeeper. Back the gatekeeper
responds to attendant analysis messages, it signals the
endpoint or aperture to use this abode in future
communications.
■ invia inbound_gatekeeper: Specifies the attendant used
for calls entering this zone.
■ outvia outbound_gatekeeper: Specifies the gatekeeper
used for calls abrogation this zone.
■ enable-intrazone: Armament all intrazone calls to use the via
gatekeeper.
zone alien other- Statically specifies a alien area if area name service
gatekeeper-name other- (DNS) is bare or undesirable.
domain-name other- ■ other-gatekeeper-name: Name of the alien gatekeeper.
gatekeeper-ip-address ■ other-domain-name: Area name of the remote
[port-number] [cost cost-value gatekeeper.
[priority priority-value]] ■ other-gatekeeper-ip-address: IP abode of the remote
[foreign-domain] [invia gatekeeper.
inbound_gatekeeper] | [outvia ■ port-number: (Optional) RAS signaling anchorage cardinal for
outbound_gatekeeper] the alien zone. The ambit is 1–65535. If the amount is not
set, the absence is the acclaimed RAS anchorage cardinal of 1719.
■ amount cost-value: (Optional) Amount of the zone. The ambit is
1–100. The absence is 50.
■ antecedence priority-value: (Optional) Antecedence of the zone.
The ambit is 1–100. The absence is 50.
■ foreign-domain: (Optional) The array is in a different
administrative domain.
■ invia inbound_gatekeeper: Specifies the attendant for
calls entering this zone.
■ outvia outbound_gatekeeper: Specifies the attendant for
calls abrogation this zone.
continues
Chapter 8: Configuring H.323 Gatekeepers 491
Table 8-2 Basal Attendant Agreement Commands (continued)
Command Purpose
zone prefix gatekeeper- Adds a prefix to the attendant area list. The alternative blast
name e164-prefix [blast | seq] and seq ambit are for accountability advanced attendant networks.
[gw-priority antecedence gw- ■ gatekeeper-name: Name of a bounded or alien gatekeeper,
alias [gw-alias, ...]] which charge accept been authentic by application the area bounded or
zone alien command.
■ e164-prefix: E.164 prefix in accepted anatomy followed by
dots (.). Anniversary dot represents a cardinal in the E.164 address.
■ blast: (Optional) If you account assorted hop-offs, this indicates
that the LRQs should be beatific accompanying to the
gatekeepers based on the adjustment in which they were listed.
The absence is seq.
■ seq: (Optional) If you account assorted hop-offs, this indicates
that the LRQs should be beatific sequentially to the
gatekeepers based on the adjustment in which they were listed.
■ gw-priority antecedence gw-alias: (Optional) Defines how the
gatekeeper selects gateways in its bounded area for calls to
numbers alpha with the defined e164-prefix. The
range is 0–10, area 0 prevents the attendant from using
the gateway’s gw-alias for that prefix, and 10 places the
highest antecedence on gateway’s gw-alias. The absence is 5.
gw-type-prefix type-prefix Configures a technology prefix in the gatekeeper. Technology
[[hopoff gkid1] [hopoff prefixes can be configured either on a attendant or directly
gkid2] [hopoff gkidn] [seq | on a gateway.
blast]] [default-technology] Back application appropriate flags (hop off or default-technology),
[[gw ipaddr ipaddr [port]]] configure the prefix on the attendant and on the gateway.
■ type-prefix: A technology prefix is accustomed and is
stripped afore blockage for the area prefix.
■ hopoff gkid: (Optional) Use this advantage to specify the
gatekeeper area the alarm is to hop off, behindhand of the
zone prefix in the destination address. The gkid argument
refers to a attendant ahead configured application the zone
local and/or area alien commands.
■ seq | blast: (Optional) If you account assorted hop offs, this indicates
that the LRQs should be beatific sequentially or simultaneously
(blast) to the gatekeepers according to the adjustment in
which they were listed.
■ default-technology: (Optional) Gateways registering with
this prefix advantage are acclimated as the absence for acquisition any
addresses that are contrarily unresolved.
492 Authorized Self-Study Guide: Cisco Voice over IP (CVOICE)
Command Purpose
■ gw ipaddr ipaddr [port]: (Optional) Use this advantage to indicate
the aperture is butterfingers of registering technology prefixes.
When it registers, it adds the aperture to the group
for this blazon prefix, aloof as if it had beatific the technology prefix
in its registration.
no abeyance Brings a attendant online.