RAI in Attendant Networks
To accredit gatekeepers to accomplish able call-routing decisions, the aperture can be configured
to abode the cachet of its ability availability to its gatekeeper. Assets that
are monitored are agenda account akin 0 (DS0) and agenda arresting processor (DSP) channel
resources.
The aperture letters its ability cachet to the attendant with the use of RAI RAS messages.
When a monitored ability avalanche beneath a configurable threshold, the gateway
sends an RAI RAS bulletin to the attendant that indicates the aperture is about out of
resources. When the accessible assets again beat addition configurable threshold, the
gateway sends an RAI that indicates the ability burning action no best exists.
Resource advertisement thresholds, as depicted in Figure 8-41, are configured by application the
resource beginning command beneath the aperture command-line interface (CLI). The
upper and lower thresholds are alone configurable to anticipate the aperture from operating
sporadically because of the availability or abridgement of resources.
100%
0%
High GW Sends RAI
“Unavailable”
GW Sends RAI
“Available” GW
RAI
RAQ
Gatekeeper
Low GK
Figure 8-41 Ability Availability Indicator Thresholds
RAI Configuration
Following is the syntax of the ability beginning command, which is accessible in Cisco
IOS to accredit RAI on endpoints.
resource beginning [all] [high percentage-value] [low percentage-value]
Use the ability beginning command in aperture agreement approach to configure a
gateway to abode H.323 ability availability to its gatekeeper. You can specify all or
specific aerial and low values. The absence for aerial and low ethics is 90. Use the no form
of this command to attenuate aperture resource-level reporting.
This command additionally includes an alternative report-policy constant to specify how resource
utilization is calculated. Accessible ability types to be appear can be either of the
following:
■ Idle-only: Includes chargeless and in-use channels only. This is the absence calculation.
■ Addressable: Includes free, in-use, and disabled channels.
RAI has to be configured on anniversary endpoint that should accelerate RAI advice in your
network. Figure 8-42 shows two gateways that accelerate RAI advice to a gatekeeper.
The attendant will analysis the RAI advice to verify the amount on anniversary aperture in
order to avenue the call.
Chapter 8: Configuring H.323 Gatekeepers 511
PSTN
UCME
(Call Agent)
Gateway1
Gateway2
Which gateway
should be acclimated for
the call?
Phone1-1
2001
PSTN Phone
Phone1-2
2002
RAI is configured on
each aperture you
want to monitor.
RAI is configured on
each aperture you
Wants to alarm PSTN phone. appetite to monitor.
Gatekeeper V
V
Figure 8-42 RAI Configuration
The RAI Feature
In Figure 8-43 and Examples 8-26 and 8-27, a aerial beginning of 70 is configured, which
represents the high-resource appliance percentage. The absence for the aerial beginning is
90 percent. After the aperture sends a high-utilization message, it waits to accelerate the
resource accretion bulletin until the ability use drops beneath the amount authentic by the
low constant (which in this case is 50). The absence for the low constant is 90 percent.
512 Authorized Self-Study Guide: Cisco Articulation over IP (CVOICE)
PSTN
Gateway1
Gateway2
Phone1-1
2001
PSTN Phone
Phone1-2
2002
Wants to alarm PSTN phone.
Gatekeeper V
V
Figure 8-43 RAI Beginning Agreement Technology
Example 8-26 RAI Beginning Agreement on Gateway1
Gateway1(config)#gateway
Gateway1(config-gateway)#resource beginning aerial 70 low 50
Example 8-27 RAI Beginning Agreement on Gateway2
Gateway2(config)#gateway
Gateway2(config-gateway)#resource beginning aerial 70 low 50
Verifying RAI Operation
Various appearance commands are accessible to verify RAI operation. The afterward examples
provide sample achievement from several of these commands.
First, the appearance alarm ability articulation beginning command can be acclimated from privileged
EXEC approach to analysis the beginning accompaniment on a gateway, as illustrated in Example 8-28.
Example 8-28 appearance alarm ability articulation beginning Command
Chapter 8: Configuring H.323 Gatekeepers 513
Router#show alarm ability articulation threshold
Resource Adviser - Dial-up Ability Beginning Information:
DS0 Threshold:
Client Type: h323
High Water Mark: 70
Low Water Mark: 50
Threshold State: low_threshold_hit
DSP Threshold:
Client Type: h323
High Water Mark: 70
Low Water Mark: 50
Threshold State: low_threshold_hit
Use the appearance alarm ability articulation statistics command to appearance the statistics of all the
resources (DSPs and DS0s).
In achievement apparent in Example 8-29, the DSP appliance is 54/112 = 48%; the DS0 utilization
is 67/96 = 70%; and the aerial beginning amount configured in both cases (DSP and DS0
utilization) is not exceeded.
Example 8-29 appearance alarm ability articulation statistics Command
Router#show alarm ability articulation statistics
Resource Adviser - Dial-up Ability Statistics Information:
DSP Statistics:
Utilization: 48 percent
Total channels: 112
Inuse channels: 54
Disabled channels: 0
Pending channels: 0
Free channels: 58
DS0 Statistics:
Utilization: 70 percent
Total channels: 96
Addressable channels: 96
Inuse channels: 67
Disabled channels: 0
Free channels: 29
The appearance aperture command, as approved in Example 8-30, can be acclimated to check
the cachet of the H.323 ability beginning if it is enabled and active. This additionally gives you
the configured low and aerial beginning values. In this output, you can see that the
“resource threshold” is enabled and active. Enabled agency configured, and Alive means
the H.323 RAS processes in the IOS are registered with the Ability Monitor.
Example 8-30 appearance aperture Command
514 Authorized Self-Study Guide: Cisco Articulation over IP (CVOICE)
Router#show gateway
Gateway Router is registered to Attendant cisco_2
Alias account (CLI configured)
H323-ID CUCME
Alias account (last RCF)
H323-ID CUCME
H323 ability thresholding is Enabled and Active
H323 ability beginning values:
DSP: Low beginning 60, Aerial beginning 70
DS0: Low beginning 60, Aerial beginning 70
You can use the appearance attendant gw-type-prefix and appearance attendant endpoint commands
to analysis the RAI cachet for anniversary aperture on the gatekeeper. Example 8-31 shows
sample achievement from the appearance attendant gw-type-prefix command.
Example 8-31 appearance attendant gw-type-prefix Command
GK#show attendant gw-type-prefix
GATEWAY TYPE PREFIX TABLE
=========================
Prefix: 1#* (Default gateway-technology)
Zone SanJose adept aperture list:
192.168.1.1:1720 ICT_CM_1
192.168.1.2:1720 ICT_CM_2
192.168.1.3:1720 CUCME (out-of-resources)
Zone SanJose prefix 2* antecedence aperture list(s):
Priority 10:
192.168.1.3:1720 CUCME (out-of-resources)
Priority 9:
192.168.1.1:1720 ICT_CM_1
Priority 8:
192.168.1.2:1720 ICT_CM_2
Also, apprehension the achievement of the appearance attendant endpoint command in Example 8-32.
Example 8-32 appearance attendant endpoint Command
Chapter 8: Configuring H.323 Gatekeepers 515
GK#show attendant endpoint
GATEKEEPER ENDPOINT REGISTRATION
================================
CallSignalAddr Port RASSignalAddr Port Breadth Name Type F
----------------- ----- -------------- ------ ---------- ------- --
192.168.1.1 1720 192.168.1.1 4085 SanJose VOIP-GW
H323-ID: ICT_CM_1
192.168.1.2 1720 192.168.1.2 4085 SanJose VOIP-GW
H323-ID: ICT_CM_2
192.168.1.3 1720 192.168.1.3 53530 Chicago VOIP-GW 0
H323-ID: CUCME
Total cardinal of alive registrations = 3
In this output, the 0 banderole in the achievement indicates that the aperture is out of resources.
Summary
The capital capacity covered in this affiliate are the following:
■ Gatekeepers are alternative accessories that are amenable for acceptance control, zone
management, and E.164 abode translation.
■ The attendant accouterments and software requirements depend on the Cisco IOS version
and affection set.
■ Signaling amid a aperture and a attendant is done through H.225 RAS.
■ Breadth prefixes announce the destination breadth for a call.
■ Technology prefixes are acclimated by gatekeepers to be added adjustable in alarm routing.
Default technology prefixes are acclimated as a aperture of aftermost resort.
■ A attendant has a analytic action for alarm acquisition that depends on technology prefix
and breadth prefix matching.
■ Agenda gatekeepers can intelligently advanced LRQs to adapted gatekeepers.
These agenda gatekeepers are acclimated for eliminating the claim for fully
meshed attendant networks.
■ Attendant Transaction Bulletin Protocol (GKTMP) provides an interface for call
control of a gatekeeper.
■ A distinct attendant can administer assorted bounded and alien zones.
■ Attendant agreement accomplish are done in attendant agreement approach on Cisco
IOS routers.
■ A breadth prefix is the allotment of a alleged cardinal that identifies the breadth to which a call
hops off. Breadth prefixes are generally acclimated to accessory an breadth cipher to a configured
zone.
■ A technology prefix is an alternative H.323 standards-based feature, accurate by
Cisco gateways and gatekeepers, that enables added adaptability in alarm acquisition within
an H.323 VoIP network.
■ Cisco IOS routers can be registered as gateways with gatekeepers.
■ A VoIP punch associate determines how to absolute calls that arise from a bounded articulation port
into a VoIP billow to a RAS affair target.
■ Breadth bandwidth administration is acclimated in an H.323 arrangement to ascendancy bandwidth in
or amid zones.
■ Cisco Unified Communications Manager can use a attendant for CAC.
■ Bandwidth adding for a attendant can be performed with an accessible formula:
(Number of Calls) * (Codec Payload Bandwidth) * 2 = Breadth Bandwidth.
■ Bandwidth commands are configured anon on the attendant in the gatekeeper
configuration mode.
■ The bandwidth command is acclimated to configure a specific bandwidth for interzone,
total, session, or absence zones.
■ RAI is acclimated in attendant networks to acquaint the attendant about the absolute status
of an end device.
■ RAI is configured on the endpoint, not on the gatekeeper.
■ RAI commands can be configured with anchored ethics or with absence values.