RAS Messages
Gatekeepers acquaint through the RAS approach application altered types of RAS messages.
Table 8-1 shows accepted RAS arresting messages, which are accomplished by a aperture or
gatekeeper.
Table 8-1 H.225 RAS Messages
Category of RAS Bulletin RAS Message
Gatekeeper Analysis Attendant Appeal (GRQ)
Gatekeeper Confirmation (GCF)
Gatekeeper Reject (GRJ)
Terminal and Aperture Allotment Allotment Appeal (RRQ)
Registration Confirmation (RCF)
Registration Reject (RRJ)
Terminal and Aperture Unregistration Unregistration Appeal (URQ)
Unregistration Confirmation (UCF)
Unregistration Reject (URJ)
Resource Availability Resource Availability Indicator (RAI)
Resource Availability Confirmation (RAC)
Bandwidth Bandwidth Appeal (BRQ)
Bandwidth Confirmation (BCF)
Bandwidth Reject (BRJ)
Location Location Appeal (LRQ)
Location Confirmation (LCF)
Location Reject (LRJ)
Call Admission Admission Appeal (ARQ)
Admission Confirmation (ACF)
Admission Reject (ARJ)
Disengage Disengage Appeal (DRQ)
Disengage Confirmation (DCF)
Disengage Rejection (DRJ)
Request in Progress Appeal in Progress (RIP)
Status Info Appeal (IRQ)
Info Appeal Acknowledgment (IRR)
Info_Request_Acknowledge (IACK)
(IRR) Advice Appeal Response
Info_Request_Neg_Acknowledge (INAK)
Information Confirm (ICF)
RAS bulletin types accommodate those listed here:
■ Attendant analysis messages: An endpoint unicasts or multicasts a gatekeeper
discovery request. The GRQ bulletin requests that any attendant accepting it
respond with a GCF bulletin acceding it permission to register. The GRJ bulletin is a
rejection of this request, advertence the requesting endpoint should seek another
gatekeeper.
■ GRQ: Bulletin beatific by an endpoint to a gatekeeper.
■ GCF: Reply from a attendant to an endpoint advertence the carriage abode of
the attendant RAS channel.
■ GRJ: Reply from a attendant to an endpoint abnegation the appeal from the endpoint
for registration. The GRJ bulletin usually occurs because of a aperture or
gatekeeper agreement error.
■ Terminal and Aperture allotment messages: The RRQ bulletin is a appeal to register
from a terminal to a gatekeeper. If the attendant responds with a RCF message,
the terminal will use the responding attendant for approaching calls. If the gatekeeper
responds with a RRJ message, the terminal charge seek addition attendant with which
to register.
■ RRQ: Beatific from an endpoint to a attendant RAS approach address. Included in
this bulletin is the technology prefix, if configured.
■ RCF: Reply from the attendant acknowledging endpoint registration.
■ RRJ: Reply from the attendant abnegation endpoint registration.
■ Terminal and Aperture unregistration messages: The URQ bulletin requests the
association amid a terminal and a attendant be broken. Note the URQ appeal is
bidirectional (that is, a attendant can appeal a terminal to accede itself unregistered,
and a terminal can acquaint a attendant it is abandoning a antecedent registration).
■ Unregistration Appeal (URQ): Beatific from an endpoint or a attendant to cancel
registration.
■ Unregistration Confirmation (UCF): Beatific from an endpoint or a attendant to
confirm an unregistration.
■ Unregistration Reject (URJ): Indicates that an endpoint was not preregistered
with a gatekeeper.
■ Alarm Admission messages: The ARQ bulletin requests an endpoint be allowed
access to a packet-based arrangement by a gatekeeper. The appeal identifies the terminating
endpoint and the bandwidth required. The attendant either grants the
request with an ACF bulletin or denies it with an ARJ message.
■ Admission Appeal (ARQ): An attack by an endpoint to admit a call.
■ Admission Confirmation (ACF): An allotment by the attendant to admit
the call. This bulletin contains the IP abode of the absolute aperture or gatekeeper
and enables the basic aperture to admit alarm ascendancy signaling
procedures.
■ Admission Reject (ARJ): Denies the appeal from the endpoint to accretion admission to
the arrangement for this accurate alarm if the endpoint is alien or inadequate
bandwidth is available.
■ Location messages: These are frequently acclimated amid interzone gatekeepers to get
the IP addresses of altered area endpoints.
■ Location Appeal (LRQ): Beatific by a attendant to the agenda attendant to
request the acquaintance advice for one or added E.164 addresses. An LRQ is sent
directly to a attendant if one is known, or it is multicast to the attendant discovery
multicast address.
■ Location Confirmation (LCF): Beatific by a responding gatekeeper, it contains the
call signaling approach or RAS approach abode (IP address) of itself or the
requested endpoint. It uses the requested endpoint abode back directed endpoint
call signaling is used.
■ Location Reject (LRJ): Beatific by gatekeepers that accustomed an LRQ for a requested
endpoint that is not registered or that has bare resources.
■ Cachet messages: These are acclimated to acquaint aperture cachet advice to the
gatekeeper.
■ Advice Appeal (IRQ): Beatific from a attendant to an endpoint requesting
status.
■ Advice Confirm (ICF): Beatific from an endpoint to a attendant to confirm
the status.
■ Advice Appeal Acknowledgment (IRR): Beatific from an endpoint to a attendant in
response to an IRQ. This bulletin is additionally beatific from an endpoint to a attendant if
the attendant requests alternate cachet updates. Gateways use the IRR to inform
the attendant about alive calls.
■ Info_Request_Acknowledge (IACK): Acclimated by the attendant to accede to IRR
messages.
■ Info_Request_Neg_Acknowledge (INAK): Acclimated by the attendant to accede to
IRR messages.
■ Bandwidth messages: An endpoint sends a bandwidth change appeal (BRQ) to its
gatekeeper to appeal an acclimation in alarm bandwidth. The attendant either grants
the appeal with a BCF bulletin or denies it with a BRJ message.
■ Bandwidth Appeal (BRQ): Beatific by an endpoint to a attendant requesting an
increase or abatement in alarm bandwidth.
Chapter 8: Configuring H.323 Gatekeepers 449
■ Bandwidth Confirmation (BCF): Beatific by a attendant acknowledging accepting of
a bandwidth request.
■ Bandwidth Reject (BRJ): Beatific by a attendant abnegation a bandwidth request.
■ Resource availability messages: RAI bulletin is a notification from a aperture to a
gatekeeper of its accepted alarm accommodation for anniversary H-series agreement and abstracts amount for
that protocol. Upon accepting an RAI message, a attendant responds with a RAC
message to accede its reception.
■ Resource Availability Indicator (RAI): Acclimated by gateways to acquaint the gatekeeper
whether assets are accessible in the aperture to booty on added calls.
■ Resource Availability Confirmation (RAC): Notification from the attendant to
the aperture acknowledging cancellation of an RAI message.
■ Appeal in Progress (RIP) message: The attendant sends out an RIP bulletin to
an endpoint or aperture to anticipate alarm failures because the RAS bulletin timeouts
during attendant alarm processing. A aperture accepting a RIP message
knows to abide to delay for a attendant response.
■ Disengage messages: Back a alarm is disconnected, a array of abstract messages
can be exchanged amid an endpoint or aperture and a gatekeeper.
■ Disengage Appeal (DRQ): Notification beatific from an endpoint or aperture to its
gatekeeper, or carnality versa.
■ Disengage Confirmation (DCF): A notification beatific from a attendant to a gateway
or endpoint acknowledging a abstract request, or carnality versa.
■ Disengage Rejection (DRJ): A notification beatific from a attendant abnegation a disconnect
request from an endpoint or gateway. Note that if a DRQ is beatific from a
gatekeeper to an endpoint, the DRQ bulletin armament a alarm to be dropped. Such a
request will not be refused.