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Table Of Contents
GKTMP Messages
This chapter describes GKTMP messages and contains the following sections:
•
Trigger Registration Messages
The GKTMP messages are used for communication between the Cisco IOS Gatekeeper and the external application. There are two types of GKTMP messages:
•
GKTMP RAS Messages—Used to exchange the contents RAS messages between the Cisco IOS Gatekeeper and the external application.
•
Trigger Registration Messages—Used by the external application to indicate to the Cisco IOS Gatekeeper which RAS message should be forwarded.
GKTMP RAS Messages
The general format of all GKTMP RAS messages is as follows:
•
Single message line
•
One or more message header lines
•
Blank line, which separates the message header from the message body
•
Zero or more message body lines
Message Line
Each GKTMP RAS message is either a request or a response. Requests are generated by the Cisco IOS Gatekeeper and responses are generated by the external application.
The first line of each GKTMP RAS message sent by the Cisco IOS Gatekeeper uses the format:
REQUEST RAS_message_type
The first line of each GKTMP RAS message sent by the external application uses the format:
RESPONSE RAS_message_type
Possible RAS message types are as follows:
•
RRQ—Registration request
•
RCF—Registration confirm
•
RRJ—Registration reject
•
URQ—Unregistration request
•
ARQ—Admission request
•
ACF—Admission confirm
•
ARJ—Admission reject
•
LRQ—Location request
•
LCF—Location confirm
•
LRJ—Location reject
•
RIP—Request in progress
•
DRQ—Disengage request
•
RAI—Resource availability information
•
BRQ—Bandwidth request
•
BCF—Bandwidth confirm
•
BRJ—Bandwidth reject
•
IRR—Information request
Note
The Cisco IOS Gatekeeper does not generate GKTMP Request RRQ messages for lightweight RRQ messages, which are used by H.323 endpoints as a keep-alive mechanism to refresh existing registrations.
Message Header
The message line is immediately followed by the message header. Each message header contains a field name and a value, separated by a colon (field:value). Table 4-1 shows the possible fields:
The message header is followed immediately by a blank line.
Message Body
The message body follows the blank line. Each line in the message body contains a tag and a value, separated by an equal sign (tag=value). The tags are case-sensitive and denote an RAS message field. The possible tags depend on the GKTMP RAS message.
Note
If the message body is null, the message must terminate with a CRFL after the message header.
In some cases, depending on the field type, the value is preceded a value-type identifier followed by a colon (tag=type:value).
Possible field types are as follows:
•
Alias-Address—This type of field can contain a series of addresses separated by spaces. Each is preceded by a value-type identifier that indicates the type of address. H indicates that the address is an H.323 ID; E indicates that the address is an E.164 address; M indicates that the address is an e-mail ID.
•
Transport-Address—This type of field contains an address. Currently, only one value-type identifier is possible for this field type. That is I, which indicates that the address is an IP version 4 address. The address is specified in dotted-decimal notation and can be followed by a colon and a port number.
•
Endpoint-Type—This type of field indicates the type of endpoint. Possible values are: gatekeeper, terminal, mcu, proxy, voice-gateway, h320-gateway, and other-gateway.
•
Supported-Prefix—This type of field indicates a supported technology prefix. Possible values are the digits 0 through 9 and the pound sign (#).
•
Globally-Unique-Identifier (GUID)—This type of field contains the 16-octet conference ID or call ID that uniquely identifies the call or conference. The IDs are specified in hexadecimal format.
•
Bandwidth—This type of field contains an unsigned integer from 0 through 4294967295 that indicates the bandwidth in 100 bits per second.
•
Boolean—This type of field contains a single character. T or t for true; F or f for false.
•
IA5 String—This type of field contains characters from the International Alphabet 5 (IA5), which is a character set defined by the ITU X.400 Message Handling System specification.
•
cryptoToken—This type of field contains one of the cryptoToken types defined for the CryptoH323Token field specified in H.225. Currently, the only type of cryptoToken supported is the cryptoEPPwdHash.
•
HASHED-EncodedPwdCertToken—This type of field contains a 16 octet IA5String. It represents the RAS Message Digest 5 (MD5) hashed encoded PwdCertToken.
•
TimeStamp—This type of field contains a 32-bit integer that represents Universal Time Coordinated (UTC) time.
•
OBJECT-IDENTIFIER—This type of field contains a sequence of non-negative integer values separated by dots, which is used to uniquely identify an object.
•
UseSpecifiedTransport—This type of field contains a string that indicates the transport layer that is used for the signaling: Annex E/UDP or TCP.
•
AlternateGK—This type of field contains a set of fields enclosed in braces ({ }). Each field is identified by a tag and separated from the other fields by SP (ASCII space, 0x20) characters. This field can contain more than one set of fields, each enclosed by braces.
•
AlternateEndpoint—This type of field contains a set of fields enclosed in braces. Each field is identified by a tag and separated from the other fields by SP (ASCII space, 0x20) characters. A message body line containing an AlternateEndpoint field must pertain to a single endpoint. Multiple call signal addresses and tokens that pertain to the same endpoint can be provided in a single message body line. If there are multiple AlternateEndpoints, each pertaining to a different H.323 endpoint, the information about the alternate endpoints must be provided in separate message body lines.
•
AlternateTransportAddress—This type of field contains a single sub-field enclosed in braces. The fields within the braces pertain to a single instance of a RAS AlternateTransportAddress structure. They are defined as a Transport-Address and are encoded as defined for the Transport-Address field.
•
clearToken—This type of field contains a set of fields enclosed in braces. Each field is identified by a tag and separated from the other fields by SP (ASCII space, 0x20) characters. The fields within the braces pertain to a single instance of a RAS ClearToken structure. However, the message line of a clearToken field can contain multiple instances, each enclosed in braces and separated by a space character. The clearToken field can be embedded within an AlternateEndpoint field.
•
remoteZone—This type of field contains a set of fields enclosed in braces. Each field is identified by a tag and separated from the other fields by SP (ASCII space, 0x20) characters. The fields within the braces pertain to a single instance of a remoteZone structure. However, the message line of a remoteZone field can contain multiple instances, each enclosed in braces and separated by a space character.
This section describes the possible fields for each message. When the external application sends a response, it includes only the fields that it has altered. Unaltered fields must not be included.
Registration Messages
Registration messages are used to control which H.323 endpoints are in the gatekeeper's zone.
This section describes the following:
Request RRQ
This message is sent from the Cisco IOS Gatekeeper to the external application when an H.323 endpoint wants to join the zone. This message can be used to populate the external application's registration database. In this case, the request is sent as a notification only and no response is expected from the external application.
Table 4-2 shows the possible Request RRQ tags:
Table 4-2 Request RRQ Tags
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldc
Transport-Address
Mandatory
RRQ:callSignalAddress. See Transport-Address.
r
Transport-Address
Mandatory
RRQ:rasAddress. See Transport-Address.
a
Alias-Address
Optional
RRQ:terminalAlias
t
Endpoint-Type
Mandatory
RRQ:terminalType
p
Supported-Prefix
Optional
RRQ:terminalType:gateway:protocol:*:supportedPrefixes
$
cryptoToken
Optional
RRQ:cryptoTokens. See CryptoToken.
T
clearToken
Optional
RRQ:tokens. See ClearToken.
C
Boolean
Optional
RRQ:callCapacityReportingCapability
K
CallCapacity
Optional
RRQ:capacity. See CallCapacity.
U
UsageReportingCapability
Optional
RRQ:UsageReportingCapability. See UsageReporting Capability.
Y
RobustnessData
Optional
RRQ:RobustnessData1 . See RobustnessData.
1 RobustnessData type is added to support Annex R implementation. The gatekeeper encodes the RobustnessData (Rrq_RDNXR *) into the REQ-RRQ message body. For example, to encode a RRQ message with Robustness Data, hasRepository bit mask set, featureSet is Needed, and a backup CSA (IP):
Y=s:t f:1 b:I:172.18.192.10:1719
Response RRQ
This message is sent from the external application to the Cisco IOS Gatekeeper in response to a Request RRQ message. If the external application has no interest in the Request RRQ message, it returns a Response RRQ with a null body. Otherwise, the external application modifies the fields as appropriate and sends the response with the updated information to the Cisco IOS Gatekeeper for further processing.
For Response RRQ, the possible tags are shown in Table 4-3:
Response RCF
This message is sent from the external application to the Cisco IOS Gatekeeper in response to a Request RRQ. This message indicates that the external application has completed the processing of the request.
For Response RCF, the possible tags are shown in Table 4-4:
Table 4-4 Response RCF Tags
Tag Field Type Mandatory or Optional Corresponding RAS Message Fielda
Alias-Address
Optional
RRQ:terminalAlias
p
Supported-Prefix
Optional
RRQ:terminalType:gateway:protocol:
*:supportedPrefixesG
AlternateGK
Optional
RCF:alternateGatekeeper. See AlternateGK.
Response RRJ
This message is sent from the external application to the Cisco IOS Gatekeeper in response to a Request RRQ. It indicates that the Cisco IOS Gatekeeper should reject the request for the specified reason.
For Response RRJ, the possible tag is shown in Table 4-5:
Table 4-5 Response RRJ Tag
Tag Field Type Mandatory or Optional Corresponding RAS Message FieldR
RRJ-Reason
Mandatory
RRJ:rejectReason
Possible values for the rejectReason are:
•
undefinedReason
•
securityDenial
•
resourceUnavailable
•
discoveryRequired
•
invalidRevision
•
invalidCallSignalAddress
•
invalidRASAddress
•
duplicateAlias
•
invalidTerminalType
•
transportNotSupported
•
transportQOSNotSupported
•
invalidAlias
•
fullRegistrationRequired
•
additiveRegistrationNotSupported
•
invalidTerminalAlias
•
genericDataReason
Unregistration Message
Unregistration messages are used to remove an H.323 endpoint from a gatekeeper zone.
This section describes the following:
Request URQ
This message is sent from the Cisco IOS Gatekeeper to the external application when the H.323 endpoint wants to leave the zone or when its registration expires. This request is sent as a notification only. No response is generated by the external application.
For Request URQ, the possible tag is shown in Table 4-6:
Table 4-6 Request URQ
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldc
Transport-Address
Mandatory
URQ:callSignalAddress. See Transport-Address.
Command URQ
The Command URQ message is sent from the application server to the gatekeeper at any time to unregister an endpoint. The gatekeeper sends a URQ message to the endpoint and removes it from its registration database. The endpoint is identified by its call signaling address (IP address and port). The server can also specify an optional reason and alternate gatekeeper information.
Table 4-7 shows the new Command URQ tags:
Table 4-7 New Command URQ Tags
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldc
Transport-Address
Mandatory
URQ:callSignalAddress. See Transport-Address.
R
URQ-Reason
Optional
URQ:reason
G
AlternateGK
Optional
URQ:alternateGatekeeper. See AlternateGK.
Possible values for the reason are:
•
reregistrationRequired
•
ttlExpired
•
securityDenial
•
undefinedReason
Result URQ
The Result URQ message is sent from the gatekeeper to the application server to report the result of a Command URQ transaction as long as the command did not specify Notification-Only: in the message header. The endpoint is identified by its call signaling address (IP address and port).
If the endpoint was found and unregistered, the message header indicates Status: success. Otherwise it indicates Status: invalidGKID or Status: invalidEndpoint.
Note
Success just means that a URQ message was sent to the endpoint and that it was removed from the gatekeeper registration database without error. It does not mean that a UCF message was received from the endpoint. The gatekeeper does not wait to receive a UCF message before sending the Result URQ message to the server.
Table 4-8 shows the new Result URQ tags:
Table 4-8 New Result URQ Tags
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldc
Transport-Address
Mandatory
URQ:callSignalAddress. See Transport-Address.
Admission Messages
Admission messages are used to control which H.323 endpoints can participate in calls.
This section describes the following:
Request ARQ
This message is sent from the Cisco IOS Gatekeeper to the external application when an H.323 endpoint wants to initiate a call.
For Request ARQ, the possible tags are shown in Table 4-9:
Table 4-9 Request ARQ
Tag Field Type Mandatory or Optional Corresponding RAS Message Fields
Alias-Address
Mandatory
ARQ:srcInfo
S
Transport-Address
Optional
ARQ:srcCallSignalAddress. See Transport-Address.
d
Alias-Address
Optional
ARQ:destinationInfo
D
Transport-Address
Optional
ARQ:destCallSignalAddress. See Transport-Address.
x
Alias-Address
Optional
ARQ:destExtraCallInfo
b
Bandwidth
Mandatory
ARQ:bandWidth
A
Boolean
Mandatory
ARQ:answerCall
c
GUID
Optional
ARQ:callIdentifier
C
GUID
Mandatory
ARQ:conferenceID
m
Boolean
Optional
ARQ:canMapAlias
e
IA5String
Optional
ARQ:nonStandardData:redirectNumber
E
integer
Optional
ARQ:nonStandardData:redirectReason1
p
integer
Optional
ARQ:nonStandardData:callingPartyNumOctet3a2
w
IA5string
Optional
ARQ:nonStandardData:displayIE
i
TransportAddress
Mandatory
arqing-endpoint identifier3
$
cryptoToken
Optional
ARQ:cryptoTokens. See CryptoToken.
T
clearToken
Optional
ARQ:tokens. See ClearToken.
B
IA5string
Optional
ARQ:nonStandardData:interfaceSpecific:BillingInfo
g
GTD
Optional
ARQ:nonStandardData:gtd. See GTD.
I
IA5String
Optional
ARQ:nonStandardData:interfaceDescriptor
J
IA5String
Optional
ARQ:circuitInfo:destinationCircuitID:group 1
K
callCapacity
Optional
ARQ:capacity. See CallCapacity.
L
IA5String
Optional
ARQ:circuitInfo:sourceCircuitID:group1
P
IA5String
Optional
ARQ:circuitInfo:sourceCircuitID:group 1
Q
IA5String
Optional
ARQ:circuitInfo:destinationCircuitID:group 1
U
IA5String
Optional
ARQ:tokens:cisco_IZCT_OID:IZCToken:izctSrcZone2
W
IA5String
Optional
ARQ:tokens:cisco_IZCT_OID:IZCToken:izctDstZone
V
Integer
Optional
ARQ:nonStandardInfo:reRouteCount 2. See ReRouteCount.
v
IA5 String
Optional
ARQ:nonStandardInfo:terminationCause:
releaseCompleteCauseIE. See ReleaseCompleteCauseIE.r
Integer
Optional
ARQ:nonStandardInfo:terminationCause:releaseCompleteReason
f
FeatureSet
Optional
ARQ:featureSet. See FeatureSet.
1 Tags `P' and `L' map to the same RAS message field (sourceCircuitID:group) while tags `J' and `Q' map to the same RAS message field (destinationCircuitID:group). This is because the ITU H.225.0v4 specification does not have separate trunk group and carrier ID RAS message fields defined. Tags `P' and `Q' in GKTMP represent the trunk group usage and tags `L' and `J' in GKTMP represent the carrier ID usage. This release of GKTMP treats carrier IDs and trunk-groups identically, leaving the proper reporting of incoming circuits and selection of outgoing circuits up to the endpoints.
2 Tags `U' and `V' are used to pass IZCT source and destination zone information to a GKTMP application server.
Possible values for the redirectReason are:
•
0—Unknown
•
1—Call forwarding busy or called DTE busy
•
2—Call forwarded, no reply
•
4—Call deflection
•
9—Called DTE out of order
•
10—Call forwarding by the called DTE
•
15—Call forwarding unconditional or systematic call redirection
CallingPartyNumOctet3a is from the Q.931 Setup octet 3a of calling party number.
When an H.323 endpoint sends an ARQ to the Cisco IOS Gatekeeper, it includes its endpointIdentifier. Because this value is local and has meaning to the Cisco IOS Gatekeeper only and not to the external application, the Cisco IOS Gatekeeper substitutes a more meaningful value of CallSignalAddress in its Request ARQ messages.
Response ARQ
This message is sent from the external application to the Cisco IOS Gatekeeper in response to a Request ARQ message. If the external application has no interest in the Request ARQ message, it returns a Response ARQ with a null body. Otherwise, it modifies the fields as appropriate and sends the response with the updated information to the Cisco IOS Gatekeeper for further processing.
For Response ARQ, the possible tags are shown in Table 4-10:
Table 4-10 Response ARQ
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldd
Alias-Address
Optional
ARQ:destinationInfo
D
Transport-Address
Optional
ARQ:destCallSignalAddress. See Transport-Address.
x
Alias-Address
Optional
ARQ:destExtraCallInfo
b
Bandwidth
Optional
ARQ:bandWidth
e
IA5String
Optional
ARQ:nonStandardData:redirectNumber
E
integer
Optional
ARQ:nonStandardData:redirectReason
w
IA5string
Optional
ARQ:nonStandardData:displayIE
z
remoteZone
Optional
None. See RemoteZone.
T
clearToken
Optional
ARQ:tokens. See ClearToken.
c
integer
Optional
None1
p
integer
Optional
None2
A
alternateEndpoint
Optional
ARQ:alternateEndpoints. See alternateEndpoint.
g
GTD
Optional
ARQ:nonStandardData:gtd. See GTD.
I
IA5String
Optional
ARQ:circuitInfo:sourceCircuitID:group
J
carrierInfo
Optional
See CarrierInfo.
F
Boolean
Optional
Do not propagate this message onward.
s
Alias-Address
Optional
ARQ:srcInfo. See Alias-Address.
P
IA5String
Optional
ARQ:circuitInfo:sourceCircuitID:group
Q
trunkGroupInfo
Optional
See TrunkGroupInfo.
y
ServiceControlSession
Optional
ACF:ServiceControlSession. See ServiceControlSession.
f
FeatureSet
Optional
ARQ:featureSet. See FeatureSet.
1 Reflects the cost value of the primary endpoint, if any, whose address is returned in the `D' field of this message. It should only be sent if the endpoint is filled in.
2 Reflects the priority value of the primary endpoint, if any whose address is returned in the `D' field of this message. It should only be sent if the endpoint is filled in.
The external application has the option of reducing the bandwidth.
If this field is included, the Cisco IOS Gatekeeper sends LRQs to all the listed zones. The zone with the least cost and highest priority that returns and LCF is chosen for inclusion in the ACF that is sent to the endpoint.
Response ACF
This message is sent from the external application to the Cisco IOS Gatekeeper in response to a Request ARQ. The message indicates that the external application has completed the processing of the request.
For Response ACF, the possible tags are shown in Table 4-11:
Table 4-11 Response ACF
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldd
Alias-Address
Optional
ACF:destinationInfo
D
Transport-Address
Mandatory
ACF:destCallSignalAddress. See Transport-Address.
x
Alias-Address
Optional
ACF:destExtraCallInfo
X
Alias-Address
Optional
ACF:remoteExtensionAddress
b
Bandwidth
Optional
ARQ:bandWidth
t
Endpoint-type
Optional
ACF:destinationType
T
ClearToken
Optional
ACF:tokens. See ClearToken.
A
AlternateEndpoint
Optional
ACF:alternateEndpoints. See alternateEndpoint.
N
AlternateTransportAddr
Optional
ACF:alternateTransportAddress
u
useSpecifiedTransport
Optional
ACF:useSpecifiedAddress. See Message Body.
g
GTD
Optional
ACF:nonStandardData:gtd:gtdData. See GTD.
s
Service-Descriptor
Optional
ACF:nonStandardData:serviceDescriptor
y
ServiceControlSession
Optional
ACF:ServiceControlSession. See ServiceControlSession.
J
carrierInfo
Optional
See CarrierInfo.
Q
trunkGroupInfo
Optional
See TrunkGroupInfo.
f
FeatureSet
Optional
ARQ:featureSet. See FeatureSet.
If the message contains an AlternateTransportAddr field, the additional field shown in Table 4-12 is included:
Table 4-12 Additional Field
Tag Field Type Mandatory or Optional Corresponding RAS Message FieldI
Transport-Address
Mandatory
IP address and port for Annex E. See Transport-Address.
Response ARJ
This message is sent from the external application to the Cisco IOS Gatekeeper in response to a Request ARQ. The message indicates that the Cisco IOS Gatekeeper should reject the request for the specified reason.
For Response ARJ, the possible tag is shown in Table 4-13:
Table 4-13 Response ARJ
Tag Field Type Mandatory or Optional Corresponding RAS Message FieldR
ARJ-Reason
Mandatory
ARJ:rejectReason
y
ServiceControlSession
Optional
ACF:ServiceControlSession. See ServiceControlSession.
v
IA5String
Optional
ARJ:terminationCause:releaseCompleteCauseIE.1 See ReleaseCompleteCauseIE.
1 This field is included if the GKTMP server wishes to provide a Q.850 cause code that it wants to be used to release the call.
Possible values for rejectReason are:
•
calledPartyNotRegistered
•
invalidPermission
•
requestDenied
•
undefinedReason
•
resourceUnavailable
•
securityDenial
•
carrierIdUnspecified (maps to undefinedReason)
•
carrierIdUnknown (maps to undefinedReason)
•
ingressCarrierInactive (maps to undefinedReason)
•
carrierOrigPcntExceeded (maps to undefinedReason)
•
carrierMaxUnitsExceeded (maps to undefinedReason)
•
destinationUnknown (maps to undefinedReason)
•
noRouteAvailable (maps to undefinedReason)
•
callerNotRegistered
•
routeCallToGatekeeper
•
invalidEndpointID
•
qosControlNotSupported
•
incompleteAddress
•
aliasesInconsistent
•
routeCallToSCN
•
exceedsCallCapacity
•
collectDestination
•
collectPin
•
genericDataReason
•
neededFeatureNotSupported
Location Messages
Location messages are used by gatekeepers to communicate with each other to process interzone calls.
This section describes the following:
Request LRQ
This message is sent from the Cisco IOS Gatekeeper to the external application when the Cisco IOS Gatekeeper has received an interzone location request.
For Request LRQ, the possible tags are shown in Table 4-14:
Table 4-14 Request LRQ
Tag Field Type Mandatory or Optional Corresponding RAS Message Fields
Alias-Address
Optional
LRQ:srcInfo
d
Alias-Address
Mandatory
LRQ:destinationInfo
e
IA5String
Optional
LRQ:nonStandardData:redirectNumber
E
integer
Optional
LRQ:nonStandardData:redirectReason1
p
integer
Optional
LRQ:nonStandardData:callingPartyNumOctet3a2
w
IA5String
Optional
LRQ:nonStandardData:displayIE
c
IA5String
Optional
LRQ:nonStandardData:callingPartyNum
T
clearToken
Optional
LRQ:tokens. See ClearToken.
g
GTD
Optional
LRQ:nonStandardData:gtd. See GTD.
I
IA5String
Optional
LRQ:nonStandardData:interfaceDescriptor
J
IA5String
Optional
LRQ:circuitInfo:destinationCircuitID:group
L
IA5String
Optional
LRQ:circuitInfo:sourceCarrierID:group
b
Integer
Optional
LRQ:nonStandardData:bandwidth
C
IA5String
Optional
LRQ:nonStandardData:callIdentifier
P
IA5String
Optional
LRQ:circuitInfo:sourceCircuitID:group
Q
IA5String
Optional
LRQ:circuitInfo:destinationCircuitID:group
S
IA5String
Optional
LRQ:tokens:cisco_IZCT_OID:IZCTToken:izctSrctZone
D
IA5String
Optional
LRQ:tokens:cisco_IZCT_OID:IZCTToken:izctDstZone
i
FromReplyAddress
Optional
See FromReplyAddress.
V
Integer
Optional
ARQ:nonStandardInfo:reRouteCount. See ReRouteCount.
v
IA5 String
Optional
ARQ:nonStandardInfo:terminationCause:
releaseCompleteCauseIEr
Integer
Optional
ARQ:nonStandardInfo:terminationCause:
releaseCompleteReasonf
FeatureSet
Optional
LRQ:featureSet. See FeatureSet.
Possible values for the redirectReason are:
•
0—Unknown
•
1—Call forwarding busy or called DTE busy
•
2—Call forwarded, no reply
•
4—Call deflection
•
9—Called DTE out of order
•
10—Call forwarding by the called DTE
•
15—Call forwarding unconditional or systematic call redirection
CallingPartyNumOctet3a is from the Q.931 Setup octet 3a of calling party number.
Response LRQ
This message is sent from the external application to the Cisco IOS Gatekeeper in response to a Request LRQ message. If the external application has no interest in the Request LRQ message, it returns a Response LRQ with a null body. Otherwise, it modifies the fields as appropriate and sends the response with the updated information to the Cisco IOS Gatekeeper for further processing.
Provisional LCF in Response LRQ
The Provisional LCF in Response LRQ feature is invoked when the `D' and `r' tags are present in the Response LRQ message. These tags carry the call signaling and RAS addresses of the provisional (primary) endpoint in the Provisional LCF. The provisional endpoint is defined as the endpoint whose transport address is carried in the `D' tag, and is sent in a LCF message if no other endpoint is found locally, or at any of the remote Cisco IOS gatekeepers.
The `D' and `r' tags are used only if a primary endpoint is not found locally or at any of the remote Cisco IOS gatekeepers. If a primary endpoint is not found, the provisional endpoint becomes the primary endpoint. However, if a primary endpoint is found, the provisional endpoint is designated as an alternate endpoint that is ranked above an alternate endpoint in an `A' tag.
The provisional endpoint is sent in a LCF message if the Provisional LCF in a Response LRQ feature is invoked, and all remote Cisco IOS gatekeepers with LRQs forwarded to them, either fail to respond or respond with LRJs.
The provisional endpoint is also sent in a LCF message if a remote Cisco IOS gatekeeper is unavailable, or has not been configured, and a search of the local database by the gatekeeper does not result in any endpoints satisfying the LRQ.
The DNIS information for the provisional endpoint can be replaced with the `d' tag. The destination carrier name of the provisional endpoint can be replaced with the first `J' tag that is not attached to a remote gatekeeper.
The `c' and `p' tags specify, respectively, the cost and priority values of the provisional endpoint. The default value for both tags is 50. The designated values for these must not rank the provisional endpoint lower than any alternate endpoint in the `A' tag in the Response LRQ. A violation of this condition results in the Cisco IOS gatekeeper overriding the designated values and replacing them with values of the highest ranked alternate endpoint in the `A' tag.
If an endpoint other than the provisional endpoint satisfies a LRQ, the message is processed with a list of alternate endpoints, arranged by their costs and priorites provided by the GKTMP server. The provisional endpoint is at the top of the list.
For Response LRQ, the possible tags are shown in Table 4-15:
Table 4-15 Response LRQ
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldd
Alias-Address
Optional
LRQ:destinationInfo
z
remoteZone
Optional
None. See RemoteZone.
T
clearToken
Optional
ARQ:tokens. See ClearToken.
c
integer
Optional
None1
p
integer
Optional
None2
A
alternateEndpoint
Optional
ARQ:alternateEndpoints. See alternateEndpoint.
g
GTD
Optional
LRQ:nonStandardData:gtd. See GTD.
I
IA5String
Optional
LRQ:circuitInfo:sourceCircuitID:group3
J
carrierInfo
Optional
See CarrierInfo. 3
F
Boolean
Optional
Do not propagate this message onward.
s
Alias-Address
Optional
LRQ:srcInfo. See Alias-Address.
Q
trunkGroupInfo
Optional
See TrunkGroupInfo. 3
P
IA5String
Optional
LRQ:circuitInfo:sourceCircuitID:group 3
f
FeatureSet
Optional
LRQ:featureSet. See FeatureSet.
D
Transport-Address
Optional
LCF:callSignalAddress4
r
Transport-Address
Optional
LCF:rasAddress 4
1 Reflects the cost value of the primary endpoint, if any, whose address is returned in the `D' field of this message. It should only be sent if the endpoint is filled in.
2 Reflects the priority value of the primary endpoint, if any whose address is returned in the `D' field of this message. It should only be sent if the endpoint is filled in.
3 Tags `P' and `I' map to the same RAS message field (sourceCircuitID:group). This is because the ITU H.225.0v4 specification does not have separate trunk group and carrier ID RAS message fields defined. Tags `P' and `Q' in GKTMP represent the trunk group usage and tags `I' and `J' in GKTMP represent the carrier ID usage.
4 The `r' tag is mandatory if the `D' tag is present.
If an endpoint is identified with a LCF received by the Cisco IOS gatekeeper, that gatekeeper consolidates and arranges all the alternate endpoints in an outgoing LCF, and may also replace the primary endpoint of its received LCF with the highest ranked alternate endpoint.
Request LCF
This message is sent from the Cisco IOS Gatekeeper to the external application when the Cisco IOS Gatekeeper has received an LCF from the remote Cisco IOS Gatekeeper. This gives the external application an opportunity to accept (Response LCF), modify (Response LCF), or reject (Response LRJ) the information contained in the LCF.
For Request LCF, the possible tags are shown in Table 4-16:
Table 4-16 Request LCF
Tag Field Type Mandatory or Optional Corresponding RAS Message Fields
Alias-Address
Optional
LRQ:srcInfo
e
IA5String
Optional
LRQ:nonStandardData:redirectNumber
E
integer
Optional
LRQ:nonStandardData:redirectReason
p
integer
Optional
LRQ:nonStandardData:callingPartyNumOctet3a
w
IA5String
Optional
LRQ:nonStandardData:displayIE
c
IA5String
Optional
LRQ:nonStandardData:callingPartyNum
d
Alias-Address
Mandatory
LRQ/LCF:destinationInfo
D
Transport-Address
Mandatory
LCF:callSignalAddress. See Transport-Address.
r
Transport-Address
Mandatory
LCF:rasAddress. See Transport-Address.
x
Alias-Address
Optional
LCF:destExtraCallInfo
X
Alias-Address
Optional
LCF:remoteExtensionAddress
t
Endpoint-Type
Optional
LCF:destinationType
N
AlternateTransportAddr
Optional
LCF:AlternateTransportAddress
u
useSpecifiedTransport
Optional
ACF:useSpecifiedAddress
T
clearToken
Optional
LCF:tokens. See ClearToken.
g
GTD
Optional
LCF:nonStandardData:gtd:gtdData. See GTD.
y
ServiceControlSession
Optional
LCF:ServiceControlSession. See ServiceControlSession.
C
IA5String
Optional
ARQ:callIdentifier
f
FeatureSet
Optional
LCF:featureSet. See FeatureSet.
The destinationInfo from the LCF is used if one is available. Otherwise, the destinationInfo from the LRQ is used.
If the message contains an AlternateTransportAddr field, the following additional field shown in Table 4-17 is included:
Table 4-17 Additional Field
Tag Field Type Mandatory or Optional Corresponding RAS Message FieldI
Transport-Address
Mandatory
IP address and port for Annex E. See Transport-Address.
Response LCF
This message is sent from the external application to the Cisco IOS Gatekeeper in response to a Request LRQ. The message indicates that the external application has completed the processing of the request.
This message can also be sent to the Cisco IOS Gatekeeper from the external application in response to a Request LCF or a Request LRJ. In the case of a Request LCF, the response can contain:
•
A null message body, which indicates that the external application accepts the information in the Request LCF.
•
Modified fields, which indicates that the external application wants to use different values than those included in the Request LCF.
In the case of a Request LRJ, the response contains an alternate destination.
For Response LCF, the possible tags are shown in Table 4-18:
Table 4-18 Response LCF
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldd
Alias-Address
Optional
LCF:destinationInfo
D
Transport-Address
Mandatory
LCF:destCallSignalAddress. See Transport-Address.
r
Transport-Address
Mandatory
LCF:rasAddress. See Transport-Address.
x
Alias-Address
Optional
LCF:destExtraCallInfo
X
Alias-Address
Optional
LCF:remoteExtensionAddress
t
Endpoint-Type
Optional
LCF:destinationType
A
AlternateEndpoint
Optional
ACF:alternateEndpoints. See alternateEndpoint.
N
AlternateTransportAddr
Optional
LCF:AlternateTransportAddress
u
useSpecifiedTransport
Optional
ACF:useSpecifiedAddress
T
clearToken
Optional
LCF:tokens. See ClearToken.
g
GTD
Optional
LCF:nonStandardData:gtd:gtdData. See GTD.
s
Service-Descriptor
Optional
LCF:nonStandardData:serviceDescriptor
y
ServiceControlSession
Optional
ACF:ServiceControlSession. See ServiceControlSession.
J
carrierInfo
Optional
See CarrierInfo.
Q
trunkGroupInfo
Optional
See TrunkGroupInfo.
f
FeatureSet
Optional
LCF:featureSet. See FeatureSet.
S
Suppress Alternate Endpoints
Optional
ACF:alternateEndpoints
The route server (RS) can send a suppress (S) tag to suppress the alternate endpoints that are sent in the outgoing ACF to the originating gateway (OGW). An example follows:
RESPONSE LCF
Version-id: 403
From: ani
To: zone1
Transaction-Id: 629EEDCC0000000A
Content-Length: 9
S=A:{ }
S -> Suppress Flag.
A -> Suppress sending of alternate endpoints in the outgoing ACF.
The suppress flag should be sent only in Response LCF if the RS receives a Request LC. The suppress flag should not be sent if the RS receives a Request LRQ.
The D and r are not required if the Response LCF is being sent in reply to a Request LCF. If the message contains an AlternateTransportAddr field, the additional field shown in Table 4-19 included:
Table 4-19 Additional Field
Tag Field Type Mandatory or Optional Corresponding RAS Message FieldI
Transport-Address
Mandatory
IP address and port for Annex E. See Transport-Address.
Request LRJ
This message is sent from the Cisco IOS Gatekeeper to the external application when the Cisco IOS Gatekeeper has received an LRJ from a remote Cisco IOS Gatekeeper. This gives the Cisco IOS Gatekeeper the opportunity to accept the rejection (Response LRJ) or propose an alternative destination (Response LCF).
For Request LRJ, the possible tags are shown in Table 4-20:
Table 4-20 Request LRJ
Tag Field Type Mandatory or Optional Corresponding RAS Message Fields
Alias-Address
Optional
LRQ:srcInfo
d
Alias-Address
Mandatory
LRQ:destinationInfo
e
IA5String
Optional
LRQ:nonStandardData:redirectNumber
E
integer
Optional
LRQ:nonStandardData:redirectReason
p
integer
Optional
LRQ:nonStandardData:callingPartyNumOctet3a
w
IA5String
Optional
LRQ:nonStandardData:displayIE
c
IA5String
Optional
LRQ:nonStandardData:callingPartyNum
R
LRJ-reason
Mandatory
LRJ:rejectReason
y
ServiceControl
SessionOptional
C
IA5String
Optional
ARQ:callIdentifier
v
IA5String
Optional
LRJ:terminationCause:releaseCompleteCauseIE1 . See ReleaseCompleteCauseIE.
1 This field is included if the GKTMP server wishes to provide a Q.850 cause code that it wants to be used to release the call.
Response LRJ
This message is sent from the external application to the Cisco IOS Gatekeeper in response to a Request LRQ. The message indicates that the Cisco IOS Gatekeeper should reject the request for the specified reason.
This message can also be sent to the Cisco IOS Gatekeeper from the external application in response to a Request LCF or a Request LRJ. In the case of a Request LCF, this response rejects the information provided in the LCF for the specified reason. In the case of a Request LRJ, this response acknowledges the rejection. The reason is optional when the Response LRJ is sent due to a Request LRJ.
For Response LRJ, the possible tag is shown in Table 4-21:
Table 4-21 Response LRJ
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldn
Boolean
Optional
LRJ:nomoreRetry
R
LRJ-Reason
Mandatory (LRQ, LCF)
Optional (LRJ)
LRJ:rejectReason
y
ServiceControlSession
Optional
ACF:ServiceControlSession
v
IA5String
Optional
LRJ:terminationCause:releaseCompleteCauseIE1 . See ReleaseCompleteCauseIE.
1 This field is included if the GKTMP server wishes to provide a Q.850 cause code that it wants to be used to release the call.
Possible values for rejectReason are:
•
notRegistered
•
invalidPermission
•
requestDenied
•
undefinedReason
•
securityDenial
•
carrierIdUnspecified (maps to undefinedReason)
•
carrierIdUnknown (maps to undefinedReason)
•
ingressCarrierInactive (maps to undefinedReason)
•
carrierOrigPcntExceeded (maps to undefinedReason)
•
carrierMaxUnitsExceeded (maps to undefinedReason)
•
destinationUnknown (maps to undefinedReason)
•
noRouteAvailable (maps to undefinedReason)
•
aliasesInconsistent
•
routeCallToSCN
•
resourcesUnavailable
•
genericDataReason
•
neededFeatureNotSupported
•
hopcountExceeded
•
incompleteAddress
The n tag is an optional boolean field. It is sent in the Response LRJ message that is generated in response to a Request LRQ message. It has a default value of false if it is not present in the Response LRJ message.
Disengage Messages
Disengage messages are used to indicate that a party wants to end the call.
Request DRQ
This message is sent from the Cisco IOS Gatekeeper to the external application to indicate that an endpoint wants to end the call.
For Request DRQ, the possible tags are shown in Table 4-22:
Table 4-22 Request DRQ
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldc
GUID
Optional
DRQ:callIdentifier
C
GUID
Mandatory
DRQ:conferenceID
R
DRQ-reason
Mandatory
DRQ:disengageReason
A
Boolean
Mandatory
DRQ:answeredCall
S
Transport-Address
Mandatory
ARQ:srcCallSignalAddress. See Transport-Address.
T
clearToken
Optional
DRQ:tokens. See ClearToken.
g
GTD
Optional
DRQ:gtd. See GTD.
K
callCapacity
Optional
DRQ:capacity. See CallCapacity.
v
IA5String
Optional
DRQ:terminationCause:releaseCompleteCauseIE. See ReleaseCompleteCauseIE.
r
IA5String
Optional
DRQ:terminationCause:releaseCompleteReason
I
UsageInformation
Optional
DRQ:usageInformation. See Usage Information.
Possible values for the DRQ-reason are:
•
forcedDrop
•
normalDrop
•
undefinedReason
Note
All Request DRQ messages must contain Notification-only in the header. No response to this message is sent.
Resource Messages
Resource messages are used to indicate the current call capacity of the gateway.
Request RAI
This message is sent from the Cisco IOS Gatekeeper to the external application to indicate the call capacity and data rate of the gateway for H.323 calls.
For Request RAI, the possible tags are shown in Table 4-23:
Table 4-23 Request RAI
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldc
Transport-Address
Mandatory
RRQ:callSignalAddress. See Transport-Address.
r
Boolean
Mandatory
RAI:almostOutOfResources
K
callCapacity
Optional
RAI:capacity. See CallCapacity.
Note
All Request RAI messages must contain Notification-only in the header. No response to this message is sent.
Bandwidth Messages
Bandwidth messages are used to request a change in bandwidth.
This section describes the following:
Request BRQ
This message is sent from the Cisco IOS Gatekeeper to the external application to request that an endpoint be allowed to change (increase or decrease) its bandwidth.
For Request BRQ, the possible tags are shown in Table 4-24:
Table 4-24 Request BRQ
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldi
Transport-Address
Mandatory
See Note. See Transport-Address.
b
Bandwidth
Mandatory
BRQ:bandWidth
C
GUID
Mandatory
BRQ:conferenceID
c
GUID
Mandatory
BRQ:callIdentifier
A
Boolean
Mandatory
BRQ:answeredCall
Note
When sending a BRQ message, an endpoint identifies itself to the gatekeeper using the endpointIdentifier that it received from the gatekeeper in the RCF. Because this endpointIdentifier has only local significance to the gatekeeper and no significance to the server, the endpoint's CallSignalAddress is used here as an identifier.
Response BRQ
The server may modify the fields shown in Table 4-25 in the BRQ.
Table 4-25 Response BRQ
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldb
Bandwidth
Optional
BRQ:bandWidth
F
Boolean
Optional
None
Response BCF
This message is sent from the external application to the Cisco IOS Gatekeeper to confirm the request to allow an endpoint to change (increase or decrease) its bandwidth. This response gives the external application the opportunity to modify the Bandwidth field of a received LCF, but because the Cisco IOS Gatekeeper is not prepared to make changes in its bandwidth, any change in the BCF will automatically generate a BRJ back to the endpoint.
For Response BCF, the possible tag is shown in Table 4-26:
Table 4-26 Response BCF
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldb
Bandwidth
Mandatory
BCF:bandWidth
Response BRJ
This message is sent from the external application the Cisco IOS Gatekeeper to deny the request to allow an endpoint to change (increase or decrease) its bandwidth.
For Response BRJ, the possible tag is shown in Table 4-27:
Table 4-27 Response BRJ
Tag Field Type Mandatory or Optional Corresponding RAS Message FieldR
BRJ-Reason
Mandatory
BRJ:rejectReason
Possible values for rejectReason are:
•
notBound
•
invalidConferenceID
•
invalidPermission
•
insufficientResource
•
invalidRevision
•
undefinedReason
•
securityDenial
Progress Messages
Progress messages provide information about the progress of a request. Progress messages include:
Response RIP
This message is sent from the external application to the Cisco IOS Gatekeeper when the external application cannot immediately process the request. This message indicates that the request is in progress (RIP) and that additional time is needed. When the Cisco IOS Gatekeeper receives this message, it forwards a request to the H.323 endpoint indicating that an extension of the timeout is required. The external application can send more that one Response RIP as is needed to process the request.
For Response RIP, the possible tag is shown in Table 4-28:
Table 4-28 Response RIP
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldd
Integer
Mandatory
RIP:delay
Possible values of the delay are 1 through 65535 milliseconds.
Request IRR
This message is sent to the GK and contains details for the call after a successful connect. A Request IRR message is sent at both the originating and terminating side of the call. If both legs reference the same GK, only one Request IRR is sent. The GK sends information for only one call in each Request IRR message.
Table 4-29 shows the new Request IRR tags:
Table 4-29 New Request IRR Tags
Tag Field Type Mandatory or Optional Corresponding RAS Message FieldS
Transport-Address
Mandatory
IRR:srcCallSignalAddress. See Transport-Address.
P
PerCallInfo
Optional
IRR:perCallInfo. See PerCallInfo.
K
callCapacity
Optional
IRR:capacity. See CallCapacity.
Request ALV
The REQUEST ALV is sent from the Gatekeeper to a GKTMP server on the detection of slower response or server failure.
This message does not contain any parameters in its body.
Response ALV
This message is returned in response to a REQUEST ALV message and does not contain any parameters in its body.
Trigger Registration Messages
Trigger registration messages are used by external applications to inform the Cisco IOS Gatekeeper which RAS messages are interesting to the external application. Interesting RAS messages trip a trigger in the Cisco IOS Gatekeeper and cause the Cisco IOS Gatekeeper to send a GKTMP RAS message to the external application.
As with the GKTMP RAS messages, trigger registration messages have the following format:
•
Single message line
•
One or more message header lines
•
Blank line, which separates the message header from the message body
•
Zero or more message body lines
Message Line
There are two types of trigger registration messages: register and unregister.
The first line of each trigger registration request/response message uses the format:
REGISTER RAS_message_type
The first line of each trigger unregistration request/response message uses the format:
UNREGISTER RAS_message_type
Possible RAS message types are as follows:
•
RRQ—Registration request
•
URQ—Unregistration request
•
ARQ—Admission request
•
LRQ—Location request
•
LCF—Location confirm
•
LRJ—Location reject
•
DRQ—Disengage request
•
RAI—Resource availability information
•
BRQ—Bandwidth request
Message Header
The message line is immediately followed by the message header. Each message header contains a field name and a value, separated by a colon (field:value). Possible fields are shown in Table 4-30:
The message header is followed immediately by a blank line.
Message Body
The message body follows the blank line. Only trigger registration requests contain a message body. Trigger registration responses, unregistration requests, and unregistration responses end after the blank line.
The message body in a trigger registration request can be used to narrow the circumstances under which the Cisco IOS Gatekeeper sends a REQUEST xxx to the external application. In this case, the external application includes tags and values in the message body that if matched will trigger the Cisco IOS Gatekeeper to generate a REQUEST xxx.
The tags that can be included vary depending on the RAS message type, and are a subset of the types that can be included in GKTMP RAS messages.
For the field type of Alias-Address, trailing wildcards can be used with E.164 addresses. An asterisk can be used to indicate a string of characters (for example, 1800*). A period can be used to indicate a single character (for example, 1800.......).
Note
Wildcards cannot be used at the beginning or in the midst of a value, only at the end. If you include a wildcard at the beginning or in the midst of a value, it will be interpreted as a literal character.
Register RRQ and RAI
For Register RRQ and RAI, the tags shown in Table 4-31 can be used to filter messages:
Register URQ
For Register URQ, the tags shown in Table 4-32 can be used to filter messages:
Register ARQ, DRQ, IRR, and BRQ
For Register ARQ, DRQ, IRR, and BRQ the tags shown in Table 4-33 can be used to filter messages:
Register LRQ
For Register LRQ, the tags shown in Table 4-34 can be used to filter messages:
Table 4-34 Register LRQ
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldd
Alias-Address
Optional
LRQ:destinationInfo
E
integer
Optional
LRQ:nonStandardData:redirectReason
Note
A gatekeeper might not be the final destination of the LRQ messages that it receives. If the queried address in an LRQ is in another Gatekeeper's zone, the LRQ is forwarded to that gatekeeper and is not resolved locally. This means that there might not be a local zone that can be associated with the LRQ. To address this situation, the gatekeeper arbitrarily uses the server registrations for the first configured local zone. Because the order in which configured zones appear can change with deletions and additions, servers should send identical LRQ registrations to all zones (all logical gatekeepers) on the same router.
Register LCF
For Register LCF, the tags shown in Table 4-35 can be used to filter messages:
Table 4-35 Register LCF
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldd
Alias-Address
Optional
LRQ/LCF:destinationInfo
X
Alias-Address
Optional
LCF:remoteExtensionAddress
Register LRJ
For Register LRJ, the tag shown in Table 4-36 can be used to filter messages:
Table 4-36 Register LRJ
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldd
Alias-Address
Optional
LRQ:destinationInfo
Additional Messages
alternateEndpoint
The alternateEndpoint field contains the tags shown in Table 4-37.
Table 4-37 alternateEndpoint Tags
Tag Field Type Mandatory or Optional DescriptionC
Integer
Optional
Cost value associated with the zone
p
Integer
Optional
Priority value associated with the zone
c
Transport-Address
Mandatory
alternateEndpoints:callSignalAddress. See Transport-Address.
J
IA5string
Optional
CarrierId
Q
IA5string
Optional
TrunkGroupLabel
T
clear-Token
Optional
alternateEndpoints:tokens
d
Alias-Address
Optional
alternateEndpoints:destination
s
Alias-Address
Optional
alternateEndpoints:sourceAlias
Usage Notes
•
The `C' and `p' parameters define the associated cost and priority of using this endpoint. The Gatekeeper merges the endpoints in the order of cost/ priority and presents an ordered list. If there are any remote endpoints, obtained by sending LRQs, they are assigned the cost value of the zone and merged accordingly.
For instance, in an ACF, the application may indicate two alternate endpoints with the following information:
A=c:{I:172.18.29.10:1780 I:172.18.29.15:1780} T:{O:1.2.3.4 p:567432 t:2345632 o:1.2.6.7 d:3452323} {O:1.2.12.23 p:129087 t:8976657 o:1.2.6.7 d:12345989} C:10 J:CARRIER_X Q:TGL_Y
A=c:{I:172.18.29.4:1780} d:{E:552601} T:{O:1.2.3.4 p:987668 t:1219889 o:1.2.6.7 d:98766343} C:5 C:10 J:CARRIER_X Q:TGL_Y
•
The first alternateEndpoint line contains multiple call signal addresses and information for multiple RAS ClearToken structures.
In this case, the multiple call signal addresses are associated with a single endpoint. Based on their cost values, the second endpoint is placed before the first in the list to be transmitted to the originating endpoint.
•
The s tag allows ANI manipulation of alternate endpoints. The route server (RS) provides the originating gatekeeper (OGK) with multiple alternate endpoints. If the OGK cannot set up a call with the primary endpoint, it tries to set up a call with the ANI and DNIS of one of the alternate endpoints provided by the RS.
If the call is not successful, the OGK tries another alternate endpoint. This process continues until the OGK is successful in setting up a call with one of the multiple alternate endpoints. If it cannot set up the call with the alternate endpoints, the call fails.
Note
The route server can send modified ANI through the GTD and the "s" tag of the alternate endpoint. When the route server is used with a call application, it should be programmed to send modified ANI in either the GTD or the "s" tag and not in both of them.
FeatureSet
Table 4-38 shows the new featureSet tags:
Example
f=n:1, f=d:3, f=s:1
Where 1 or 3 is the feature identifier for a particular feature.
GTD
The Generic Transparency Descriptor (GTD) field type is a structure comprising of two sub-fields: length and data. This field type is required for values that contain <cr><lf> pairs in its body. The length (B) sub-field indicates the size of the data sub-field and indicates to the parser that any occurrence of <cr><lf> within the data sub-field is not a <tag>=<value> delimiter.
Table 4-39 shows the new GTD tags:
Usage Notes
The GTD field type is different from other GKTMP fields in that <cr><lf> does not indicate the end of the GTD line. The following rules must be followed in processing the GTD field type:•
Use `g' as a GTD tag across all REQUEST and RESPONSE messages.
•
The length of the GTD data sub-field is specified by `B' and is represented by five ASCII digits.
•
A `B' sub-field is delimited by `:'.
•
<cr><lf> or <lf> within the GTD body should not be interpreted as a tag or value delimiter. The <cr><lf> after the GTD sub-field—specified by length sub-field—is the delimiter.
•
The GTD field should not be included in any tag other than `g'.
•
Gatekeeper to Server:
–
`g=B:<Five ASCII digits>:<data>' should be used to send the GTD.
–
`g=' is illegal.
–
The absence of a `g' tag indicates there is no GTD data.
–
All other `g' tag formats are illegal
•
Server to Gatekeeper:
–
The `g' tag can only be sent in a RESPONSE message corresponding to a REQUEST message from the gatekeeper in which a GTD is present. The server cannot generate and send a GTD if it has not received a GTD from the gatekeeper.
–
`g=B:<Five ASCII digits>:<data>' indicates the server is returning the GTD it received in a request from the gatekeeper. (This GTD could be a modified version of gatekeeper GTD.) The gatekeeper should replace its cached copy of the GTD with the received copy of the GTD.
–
`g=' indicates that server wants the gatekeeper to retain its copy of the GTD.
–
The absence of a `g' tag indicates that the gatekeeper should delete its copy of GTD.
•
The gatekeeper should not send a `g' tag or value if the server GKTMP version is less than version 4.1. Versions below version 4.1 cannot interpret the GTD and <cr><lf> may not delimit the GTD tagor value, so these lower versions cannot to skip the `g' tag line.
Format
g=B:<Length in 5 ASCII digits>:<Data>
Example
g=B:00003:1AB
ReRouteCount
The reRouteCount can be used by the originating gateway to send additional ARQs to the gatekeeper and then to a route server after all the alternative endpoints returned in the first ARQ have failed. The subsequent ARQs use the same global call ID and will also have a reroute count that is set to one for the first reroute request (second ARQ) and is incremented for each subsequent reroute request.
Table 4-40 shows the tags for the reRouteCount field:
Table 4-40 ReRouteCount Tags
Tag Field Type Required or Optional DescriptionV
Integer
Optional
Number of reroute requests.
RobustnessData
The RobustnessData can be sent from gateway to gatekeeper to indicate that the endpoint (GW) is supporting Annex R. The GKTMP messages, REQ-RRQ/RSP-RRQ/RSP-RCF, REQ-ARQ/RSP-ARQ/RSP-ACF, REQ-LRQ/REQ-LCF/RSP-LRQ/RSP-LCF can contain RobustnessData. The GKTMP can change the values of the RobustnessData in the response messages.
Table 4-41 shows the tag being added to the RobustnessData field:
Table 4-41 RobustnessData Tags
Tag Field Type Required or Optional Descriptions
Boolean
Optional
hasSharedRepository1
b
Transport-Address
Optional
List of backup endpoint CSAs2
1 Information hasSharedRepository indicates the Method B Robustness.
2 Backup CallSignalAddress can have a list of backup endpoint addresses.
b:{I:172.18.192.10:1780 I:172.18.196.1:1719}
Braces should always be put around the contents, even if it is only a single CSA. For example:
Y=b:{I:1.1.1.1:2}
Y=s:t b:{I:1.2.3.4:5 I:6.7.8.9:10}
AlternateGK
A message body line containing a field of type AlternateGK contains a set of fields enclosed within curly braces "{ }". Each of the fields within the curly braces are identified by a tag, with each field separated by SP (ascii space, 0x20) characters.Table 4-42 shows the AlternateGK tags:
Table 4-42 AlternateGK Tags
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldr
Transport-Address
Mandatory
AlternateGK:rasAddress. See Transport-Address.
g
Alias-Address
Optional
AlternateGK:gatekeeperIdentifier. See Alias-Address.
n
Boolean
Mandatory
AlternateGK:needToRegister
p
integer
Mandatory
AlternateGK:priority
FromReplyAddress
The from IP address is the address from which an LRQ message was received. The reply-to address is the mandatory IP address specified in the RAS LRQ message replyAddress field. A GKTMP application can use these fields to authenticate the source of LRQ message.
Table 4-43 shows the FromReplyAddress tags:
ServiceControlSession
Table 4-44 shows the new Service Control Session tags:
A message body line carries one or more remote zone definitions. The following example depicts a message body line comprising two zone definitions. Allowable values for cost and priority are between 1 and 100.
z={r:I:172.18.29.10:1719 d:E:552601 c:10 p:10} {r:I:172.18.29.15:1719 c:15 p:10}
Usage Notes
Any clear tokens returned with the remote zone definition are sent in the LRQ to that zone.
Usage Information
The Usage Information field can be sent from the gateway to gatekeeper to report the billing information about the call. It can be included within DRQ at the end of the call. It can contain the alert time, connect time, end time, and release source for the call. Table 4-45 shows the Usage Information tags:
UsageReporting Capability
The UsageReporting Capability is sent by the gateway to the gatekeeper to report its ability to collect and report usage information. It specifies if the endpoint has the capability to report the start, endtime, and termination cause of the call to the gatekeeper. It is sent within RRQ upon registration. Table 4-44 shows the UsageReporting Capability tags:
CallCapacity
The CallCapacity message indicates the ability of the gateway to accept each type of call the gateway supports, such as voice calls.
Table 4-47 shows the CallCapacity tags:
CarrierInfo
The gatekeeper sends incoming carrier information received in a RAS ARQ message from the gateway to an external GKTMP application. This information allows the application to select an outbound carrier and remote zones that the carrier may exist in. The gatekeeper uses this outbound carrier and zone information to query for the egress gateway.
Table 4-48 shows the new Carrier Information tags:
Table 4-48 CarrierInfo Tags
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldi
IA5String
Mandatory
destination carrierID
p
Integer
Optional
Priority of this carrier
z
remoteZone
Optional
Remote zone information. See RemoteZone.
TrunkGroupInfo
Table 4-49 shows the new Trunk Group Information tags:
Table 4-49 TrunkGroupInfo Tags
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldi
IA5String
Mandatory
Destination trunk group
p
Integer
Optional
Priority of this trunk group
z
remoteZone
Optional
Remote zone information. See RemoteZone.
Alias-Address
A field of type Alias-Address contains a sequence of aliases separated by SP (ascii space, 0x20) characters. Each alias is prefixed by one of the following type characters, followed by a colon:
•
H: an H.323-ID
•
E: an E.164 address
•
M: an email ID
For example, in an RRQ message, a terminal alias containing the sequence of an H.323-ID of "John Smith", an E164 address of 4085551212, and an email-id of "jsmith@somewhere.com" is indicated by the line: a=H:"John Smith" E:4085551212 M:jsmith@somewhere.com
PerCallInfo
If the message contains a PerCallInfo field, the following fields shown in Table 4-50 are included:
ReleaseCompleteCauseIE
ReleaseCompleteCauseIE, also known as terminationCause, is sent to the GKTMP application to inform the GKTMP server that a release complete cause IE was sent to the Gatekeeper.
Table 4-51 shows the ReleaseCompleteCauseIE tags:
RemoteZone
A remoteZone is a structure type comprised of multiple sub-fields. Each sub-field type within the remoteZone is identified with a tag and the associated data is enclosed with curly braces "{ }". The fields within the curly braces pertain to a single instance of a remoteZone structure. The message line with a remoteZone field can contain multiple instances, each enclosed within curly braces and separated by a space character. Each of the sub-fields themselves are separated by a space character.
Table 4-52 shows the remoteZone field tags:
Table 4-52 RemoteZone Tags
Tag Field Type Mandatory or Optional Descriptionr
Transport-Address
Mandatory
RAS address of the zone. See Transport-Address.
c
Integer
Optional
Cost value associated with the zone
p
Integer
Optional
Priority value associated with the zone
T
clearToken
Optional
ARQ:tokens. See ClearToken.
s
Alias-Address
Optional
ANI manipulation of alternate endpoints.
The "s" tag allows ANI manipulation for a remote zone. The route server (RS) provides the directory or originating gatekeeper with multiple remote zones to contact for resolving the E.164 number. With the s tag, it provides a unique ANI for each of the remote zones, where the ANI for a remote zone is sent in the non-standard field of the LRQ that is forwarded to that remote zone.
Example
This is an example of modified ANI with a z tag:
z={r:I:172.18.29.10:1719 d:E:552601 c:10 p:10} {r:I:172.18.29.15:1719 c:15 p:10}
Usage Notes
Any Cleartokens returned with the remote zone definition are sent in the LRQ message to that zone.
Transport-Address
The only type of transport address currently supported by the gatekeeper is IP version 4. However, a type prefix is defined for future extensibility. For example, I: IP version 4 address.
The address is specified in the usual dotted string form, followed by a colon and port number. For example, the callSignalAddress in an RRQ message may be specified as: c=I:172.21.137.4:1720.
ClearToken
If the message contains a clearToken field, the fields shown in Table 4-53 are included:
CryptoToken
If the message contains a cryptoToken field, the additional fields shown in Table 4-54 are included:
CallMode
The CallMode field type contains multiple info-type fields. The info-type field denotes the type of media that is present in a call and is represented by an integer, such as 1 for voice, 2 for fax, or 3 for modem. There can be one or more info-type fields in a CallMode entry. Table 4-55 shows the CallMode field type.
Table 4-55 CallMode Field
Tag Field Type Mandatory or Optional Corresponding RAS Message Fieldi
Integer
Mandatory
CallMode:infotype
Posted: Mon Apr 10 00:16:48 PDT 2006
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