Manual

Cisco Packet Data Serving Node (PDSN) Release 2.0

Resource Management

12.3(11)T

Step 12 When the user disconnects, the MS initiates release of the call and the traffic channel is released. The

PDSN clears the session and sends an Accounting Request Stop record. The record includes the prepaid

VSAs to report final usage.

Step 13 The RADIUS Server updates its own records and sends final usage report to PBS. The PBS updates the

user’s account and replies to the AR. And the AR sends the Accounting Response to PDSN.

Prepaid Mobile IP Call Flow

In the following scenario, the prepaid user makes a Mobile IP data call. The user runs out of quota during

the mobile IP data session and the PDSN disconnects the call. The call flow shows a single Mobile IP

flow; however, additional flows are established and handled in a similar manner when the MS sends

additional Mobile IP Registration Requests.

Step 1 The MS originates a call by sending an Origination message. A traffic channel is assigned, but the MS

skips CHAP.

Step 2 The PDSN completes the PPP connection. Since the MS skips IP address assignment during IPCP the

PDSN assumes Mobile IP.

Step 3 The PDSN sends an Agent Advertisement with a FA-CHAP challenge, and the MS initiates a Mobile IP

Registration Request with FA-CHAP response.

Step 4 The PDSN sends the Access Request with FA-CHAP to the AR. The AR looks up the user’s profile and

determines that the user has prepaid service. It the sends an authentication request to the billing server.

Step 5 The billing server checks that the user has sufficient quota to make a call and returns an ok. The RADIUS

Server sends an Access Accept message to the PDSN that indicates a prepaid user.

Step 6 The PDSN forwards the mobile IP Registration Request to the Home Agent and receives a Registration

Reply. The PDSN forwards the reply to the MS.

Step 7 The PDSN sends an Access Request for initial quota authorization. The request contains Service Id VSA

that indicates this is a Mobile IP call. The AR, knowing that this is a prepaid user, sends the initial quota

authorization request to the PBS. The billing server returns the quota information to the AR, who

includes the quota information in the Access Accept message and sends it to the PDSN.

Step 8 The PDSN saves the received quota information and monitors the user data against this. When the quota

is used up, the PDSN sends an Access Request to AR indicating the usage and reason “Quota Depleted.”

Step 9 The AR sends re-authorization request to the PBS, who updates the user’s account, allocates additional

quota, and returns the new quota information to the AR.

Step 10 The AR includes the new quota information in the Access Accept message and sends it to the PDSN.

The PDSN updates the new quota information in its tables, and adjusts usage to allow for quota used

since the Access Request was sent. The PDSN then continues to monitor the user data. Steps 8-10 are

repeated as long as the user has sufficient funds.

Step 11 If the PDSN requests an additional quota but the user has run out, the PBS rejects the request with reason

“Exceeded Balance,” and the AR sends an Access Reject to PDSN.

Step 12 The PDSN deletes the Mobile IP flow, determines that this is the last flow, and requests release of the

A10 connection by sending A11-Registration Update to the PCF. The PCF sends an ack message and

initiates release of the traffic channel.

Step 13 The PDSN clears the session and sends an Accounting Request Stop record. The record includes the

prepaid VSAs to report final usage.