Manual

Cisco Packet Data Serving Node (PDSN) Release 2.0
Resource Management
21
12.3(11)T
Step 6 The Billing Server does not allocate a new quota when the user indicates “Quota reached” for the prepaid
flow. The Billing Server terminates the prepaid flow and indicates the same to the HAAA. HAAA sends
an Access-Accept message to the PDSN acknowledging the termination of the Prepaid packet data
session by encapsulating Update Reason Sub-type as “Quota is reached” inside PPAQ VSA.
When the PDSN receives the Access Accept message, it clears the user flow for the Prepaid session. As
part of the usual off-line accounting procedures, the PDSN sends an off-line RADIUS Accounting-Stop
message upon successful release of the appropriate resources.
Volume-based Prepaid Data Service with Tariff Switching
The PDSN and Billing Server support tariff switch, volume- based, Prepaid packet data service. The
tariff switch trigger is controlled at the Billing Server. To support this capability, a new sub-Type
PrepaidTariffSwitch (PTS) VSA attribute is sent by HAAA to PDSN. This attribute contains following
key sub-types:
• QuotaId: Quota Id is same as present in PPAQ.
• VolumeUsedAfterTariffSwitch (VUATS): Volume switched after Tariff Switch
• TariffSwitchInterval (TSI): Interval in seconds between the time stamp (G4) of the corresponding
on-line RADIUS Access-Request message and the next tariff switch condition
The following sequence describes the functionality of Prepaid data service when Tariff Switching is
enabled.
Step 1 The Prepaid capable PDSN determines that Simple IP or Mobile IP setup requires a RADIUS
Access-Request message to be sent to the Home RADIUS Server. For SIP sessions, authentication of the
user with AAA has to be done instead of local authentication. In case of Mobile IP users, authentication
via FA-CHAP is required.
PDSN includes its own PPAC VSA to inform the HAAA/Billing Server that it supports Prepaid based
on Volume (value = 1 or 3). If resource revocation is enabled on the PDSN, then it will send a
SessionTerminationCapability (STC) attribute indicating that it can support resource revocation for
Mobile IP sessions.
The Home RADIUS server performs the regular Authentication and Authorization of the Access Request
sent by the user. If the user profile indicates the user is a Prepaid subscriber, HAAA interfaces with the
Billing Server and provides the Billing Server with the prepaid related info for the user as received in
the Access Request message.
Step 2 After the Billing Server receives the user’s prepaid info, it checks the capabilities of the PDSN that were
sent in the PPAC VSA. It also checks that the user has a valid balance and account status. The Billing
Server notifies the PDSN that it will support prepaid packet data service that is based on Volume. The
Billing Server also assigns the initial quota for the user, which is typically fraction of total available
quota for the user. The quota allocated for the user is identified by a quota id assigned by Billing Server
for the user. The Billing Server interfaces with the HAAA and provides this info to the HAAA.
The Billing Server that supports Tariff Switching indicates the time (in seconds) remaining for the next
tariff switch point, and passes the info to the HAAA server. Optionally, it can include the time after tariff
switch point that the PDSN will send Access Request to the HAAA if the threshold value for the assigned
quota is not reached.