Diameter protocol

CCR (Credit-Control-Request)

Y

Y

This message is sent to request credit authorization for a given service. A single CCR request is sent for event-based charging (e.g., for SMS), when it is sure that the requested service event will be successful.

In the case of session-based charging, multiple CCR messages are sent within the session.

Thus, CCR messages can be of these types:

• The initiation request (CCR-I) is sent when a subscriber logs in and AAA is requested to activate the subscriber’s session.

• The update request (CCR-U) is sent when a usage threshold is reached. The CCR-U reports the actual usage for all statistics.

• The termination request (CCR-T) is sent to terminate a credit-control session and contains credit-control information relevant to the existing session.

• The event request is sent in the case of a one-time scenario with direct debiting. It contains all the information relevant to the service.

CCA (Credit-Control-Answer)

Y

Y

This is the message to acknowledge the credit control request. Accordingly, CCA messages fall into:

• CCA-I – indicates the success or failure to activate a subscriber’s session depending on whether they have sufficient credit for the requested service.

• CCA-U – is the response to the CCR-U message, wherein new quotas of credit resources (e.g., validity time or usage quotas) are returned.

• CCA-T acknowledges the termination of the user session.

• CCA message with the Event request type is the response to the request and contains the estimated total cost for the requested service.

RAR (Re-Auth-Request)

Y

This message is sent to initiate the credit re-authorization for a whole (sub-)session, a single credit pool, a single service, or a single rating-group. The Auth-Application-Id in the RAR message is set to 4 to indicate Diameter Credit Control, and the Re-Auth-Request-Type is set to AUTHORIZE_ONLY.

RAA (Re-Auth-Answer)

Y

This message is sent to acknowledge the RAR message and is followed by a Credit-Control-Request message with the CC-Request-Type AVP set to the value UPDATE_REQUEST. The Result-Code 2002 (DIAMETER_LIMITED_SUCCESS) SHOULD be used in the RAA message to indicate that an additional message (i.e., CCR message with an UPDATE_REQUEST value) is required to complete the procedure.

Session-Id

Y

Y

This identifies the operation session.

Origin-Host

Y

Y

This identifies the endpoint that originated the Diameter message.

Origin-Realm

Y

Y

This contains the Realm of the originator of any Diameter message and must be present in all messages.

Destination-Realm

Y

This contains the realm of the host that the message is to be routed to. The realm is addressed with the domain address of the corresponding public URI.

Result-Code

Y

This indicates whether a particular request is successfully completed or whether an error occurred. The Result-Code data field contains an IANA-managed 32-bit address space that represents errors.

Auth-Application-Id

Y

Y

This corresponds to the application ID of the Diameter Credit Control Application and is defined with the value 4.

Service-Context-Id

Y

This AVP contains a unique identifier for the Diameter Credit Control service specific document that applies to the request. This identifier is allocated by the service provider, by the service element manufacturer or by a standardization body. The format for the Service-Context-Id is:

service-context @ domain, where:

• “service-context” is an arbitrary string of characters and digits.

• “domain” represents the entity that allocates the Service-Context-Id (e.g., ietf.org, 3gpp.org, etc.).

CC-Request-Type

Y

Y

This contains the reason for sending the credit-control request message.

Possible values:

• INITIAL_REQUEST

• UPDATE_REQUEST

• TERMINATION_REQUEST

• EVENT_REQUEST

CC-Request-Number

Y

Y

This AVP contains the sequence number of the messages sent.

Currency-Code

Y

This specifies in which currency (ISO 4217) the values for AVPs containing monetary units are given.

Proxy-Host

Y

Y

This field contains the identity of the host that added the Proxy-Info field.

Proxy-State

Y

Y

This field contains state local information.

Subscription-Id-Data

Y

This field contains user data content, e.g., the MSISDN.

Subscription-Id-Type

Y

This field determines the identifier type, e.g., 0 is used for the international E.164 format according to the ITU-T E.164 numbering plan.

Determination of base units used for resource allocations

h323-ivr-out=PortaBilling_Authorize:base

CC-Time, CC-Input-Octets, CC-Output-Octets, CC-Total-Octets, CC-Service-Specific-Units

Reporting of units used (incremental charging)

h323-ivr-out=PortaBilling_Authorize:delta-used

Used-Service-Unit

Requesting the next units to be granted

h323-ivr-out=PortaBilling_Authorize:max, h323-ivr-out=PortaBilling_Authorize:min

Requested-Service-Unit

Limiting the time for session granted resources

h323-ivr-in=PortaBilling_Authorize:expires

Validity-Timeout

Responding with available (granted) units

h323-ivr-in=PortaBilling_Authorize:avail

Granted-Service-Unit

Charging context

h323-ivr-out=PortaBilling_AccessCode, h323-ivr-out=PortaBilling_RatePattern, h323-ivr-in=PortaBilling_AccessCode, h323-ivr-in=PortaBilling_RatePattern

Rating-Group, Service-Identifier, Service-Context-ID