Manual

Cisco Packet Data Serving Node (PDSN) Release 2.0

Resource Management

12.3(11)T

Once the flow for the user comes up (for example, an IP address assigned for Simple IP or MIP RRP

received from the HA and sent to the MS), the PDSN starts the timer corresponding to the duration

threshold value and duration quota value.

Step 3 Once the timer expires for the threshold value of the allocated quota for the prepaid flow, the PDSN

sends an Access-Request Message to AAA to refresh quota for the prepaid flow. This Access Request

message contains a PPAQ VSA, which includes following parameters:

• Update-Reason Sub-Type that is set to indicate 'Threshold reached' (= 3)

• Quota ID previously received

• Used duration in the DurationQuota Sub-Type

The HAAA authorizes the RADIUS packet and, if successful, forwards the prepaid-related information

in the packet to the Billing Server.

Step 4 The Billing Server updates its database with the amount of quota used by the user. Since the user

indicates quota renewal, the Billing Server apportions a fraction of prepaid account balance of the user.

It also assigns a new Quota ID for the current allocated quota and a corresponding threshold value for

the assigned quota. This information is passed on to the HAAA.

The HAAA sends the information received from the Billing Server into a RADIUS Access-Accept

message to be sent to the PDSN. The attributes that are encapsulated into a PPAQ VSA include:

• Quota ID

• Allocated quota into DurationQuota parameter

• Threshold corresponding to the assigned quota into DurationThreshold parameter.

After the PDSN receives the Access-Accept message from the AAA, it parses the RADIUS packet and

retrieves the attributes inside it. The PDSN stores the information in the packet, updates it with the quota

allocated for the flow and the current threshold value corresponding to the allocated flow. The PDSN

restarts the duration quota timer with the new value received in the Accept Accept message, and starts

the threshold timer with the new threshold value received corresponding to the current quota. It also

stores the new Quota-ID allocated for the current quota.

Step 5 The PDSN closes the prepaid flow based on following criteria:

• An Access-Request message was sent to renew the quota, and the corresponding Access-Accept

message was not received from AAA after a configurable time value. This time value is same as the

RADIUS message timeout configured on PDSN.

• An Access-Accept was sent to retrieve quota before the Access-Accept can be received, and the

remaining DurationQuota is consumed and the timer corresponding to it expires. This event is when

the DurationQuota value and the DurationThreshold values become the same.

If this event occurs, the PDSN sends an Access-Request message containing the PPAQ VSA that

includes:

–

Update-Reason Sub-Type to indicate ‘Quota reached’ (= 4)

–

Amount of quota used by the user in DurationQuota attribute.

The PDSN marks the prepaid flow for deletion, and does not switch any packets through it for the

prepaid flow. The PDSN does not delete the prepaid flow immediately, and waits for the response of the

Access-Request or timeout of the Access-Request message.