Ro online charging Web service call
flows describe how the application transmits and receives accounting packets
(credit control request (CCR), credit control answer (CCA)) and
reauthorization packets (Reauthorization Request (RAR), Reauthorization Answer
(RAA)). It also describes how the Diameter Enabler base interacts
with the Application client and the Online Charging System (OCS).
Diameter Enabler base supports
multiple realms. The internal routing table controls which realm a packet
is sent to.
The Ro online charging Web service application
validates the parameters received from the Web service interface; then, builds
a Diameter packet (CCR) using the RoChargingInfo parameter. The Ro Web service
application passes the Diameter packet to the Diameter Enabler base.
Ro online charging Web service uses
two key flows (request/reply and subscribe/notify) to handle charging transactions:
- Request/Reply flow:
- An IMS™ Application Server,
the SIP application, invokes one of the Ro online charging Web service methods,
such as sendCCInitial.
- The Ro online charging Web service application
validates the parameters received from the Web service interface; then, builds
a Diameter packet (CCR) using the RoChargingInfo parameter that is sent to
the Diameter Enabler base.
- The Diameter Enabler base sends
the Diameter request message to the OCS.
- The OCS receives the request message, updates the number of "used units"
from the subscriber's account, reserves quota for the subscriber, and returns
the result (CCA) to the Diameter Enabler base.
- The Diameter Enabler base passes
the response to Ro online charging Web service application.
- The Ro online charging Web service application
validates this reply and checks for any violations; then, once verified, extracts
the information from the CCA and builds a result using the RoChargingResults
object that is returned to the SIP application that invoked the Web service
request.
- The SIP application interprets the result and processes the charging information.
- Subscribe/Notify flow:
- An IMS Application service invokes the subscribeCCReAuth Web service method,
specifying a sessionId and realm, for which it wants to receive reauthorization
notifications. In addition, the caller specifies the callbackURL of the application
that implements the DiameterRoNotify Web service interface.
- The Ro online charging Web service application
validates the request and adds a subscription record to the data store, which
will remain active for the expiration duration specified in the subscription
request.
- The OCS sends a RAR to the Diameter Enabler to
request that a user is reauthorized for the charging session. The RAR is validated
for correctness and a ReAuthInfo object is created. The Diameter Enabler responds to the OCS with a RAA message.
- The Ro online charging Web service application
searches the subscription database for the Session-Id and Origin-Realm found
in the RAR.
- If the subscription is active, the callbackURL is retrieved and the Diameter Enabler invokes
the notifyCCReAuth Web service request, sending the ReAuthInfo object to the
remote DiameterRoNotify Web service.