> Pre-paid Billing
> This chapter provides information on configuring an enhanced, or extended, service. The product administration guides provides examples and procedures for configuration of basic services on the system. It is recommended that you select the configuration example that best meets your service model and configure the required elements for that model before using the procedures in this chapter.
> This chapter includes the following topics:

> • | Overview

> • | Configuring Standard 3GPP2 Pre-paid Billing

> • | Configuring Pre-paid Billing With Custom Behavior

> • | 3GPP2 Pre-paid Attributes

> • | Pre-paid Attributes

> Overview
> The system supports pre-paid billing for subscriber accounts that use RADIUS Accounting. 3GPP2 pre-paid billing support is disabled by default and you must obtain and install a license key to enable it.
> The system supports two methods of implementing Pre-paid Billing Support; Standard 3GPP2 Pre-paid Billing and Custom Pre-paid Billing. The 3GPP2 standard is the recommended implementation.
> 3GPP2 Standard Pre-paid Billing Overview
> The prepaid packet data service allows a user to purchase access to the network in advance, based on either volume or duration. When a user connects to a service, the Prepaid Client (PPC) contacts the Prepaid Server (PPS) and verifies that the user has available credits for the service. When a user runs out of credits, service is terminated until the user purchases additional credits.
> The Prepaid Data Service implementation is compliant with 3GPP2 IS-835-C. This solution provides a standards based implementation that can effectively interoperate with additional vendors equipment when required. The system primarily uses the PPAC (PrePaid Accounting Capability) and PPAQ (PrePaid Accounting Quota) VSAs to implement PrePaid service. The PPAC VSA is used to determine the capabilities of the PPC. When the PPC sends the PPAC VSA it specifies if it supports duration, volume or both types of PrePaid service. When the PPS sends a PPAC VSA it specifies the type of PrePaid service to use for the particular session. The PPAQ VSA specifies the characteristics of the PrePaid accounting service. This includes quota & threshold values for both duration and volume PrePaid service. Through the use of these VSAs, the PPC and PPS communicate the status of the session and when the user has run out of quota, the service can be terminated.
> The PrePaid Client resides on the system and communicates with the PPS through the use of RADIUS messages exchanged with the RADIUS server.
> Custom Pre-paid Billing Overview
> In the Access-Accept from the RADIUS server the system receives attributes which indicate the number of byte credits available for the subscriber. Byte throughput can be pre-paid for traffic inbound to the system, outbound from the system, or an amount that combines both inbound and outbound traffic. Five attributes are used: one for traffic inbound to the system, one for traffic outbound from the system, one that combines traffic in both directions, one that only indicates that the user should be re-authenticated regardless of the byte counters, and one for the low watermark in percent.
> The low watermark value is multiplied by the number of byte credits granted in the Access-Accept to arrive at a threshold. Once the number of byte credits remaining is lower than this number, a new Access-Request is issued. If the Access-Request is issued because the Low Watermark has been reached, then a new Low Watermark is calculated from the number of byte credits granted in the Access-Accept, but only if the number of byte credits granted is a non-zero value. If the Access-Request is issued for any other reason, then the Low Watermark is not re-calculated.
> The system re-authorizes an active subscriber that has used up its byte credits by issuing a RADIUS Access-Request to the RADIUS server. A valid Access-Reject or a RADIUS timeout results in immediate disconnect of the subscriber session. An Access-Accept without attributes that authorize more byte credits allows the subscriber session to continue with the remaining credits. An Access-Accept with attributes containing byte credits results in the addition of these byte credits to the subscriber session, and the continuation of the session until the subscriber session byte credits have been reduced to the low watermark received in the access accept. If not received, it defaults to 10%.
> The system continues to service the subscriber session while the RADIUS request for re-authorization is in process. If the counter reaches zero before the response the subscriber session is terminated immediately.
> You can configure Pre-paid Billing support for standard 3GPP2 behavior or custom behavior where you can specify whether or to measure the bye-count on compressed or non-compressed data, set a low-watermark for accounting, and specify a credit renewal interval in the default subscriber configuration for a context or a domain alias.
> Configuring Standard 3GPP2 Pre-paid Billing
> This section describes how to enable standard 3GPP2 pre-paid billing support.
> Important: Commands used in the configuration samples in this section provide base functionality to the extent that the most common or likely commands and/or keyword options are presented. In many cases, other optional commands and/or keyword options are available. Refer to the Command Line Interface Reference for complete information regarding all commands.
> Enable pre-paid billing for the default subscriber by applying the following example configuration:
> configure
> context <context_name>
> subscriber default
> prepaid 3gpp2 accounting
> end
> Enable pre-paid billing for the default subscriber of a domain alias by applying the following example configuration:
> configure
> context <context_name>
> subscriber name <alias_def_sub>
> prepaid 3gpp2 accounting
> end
> Notes:

> • | You may add the optional keyword no-final-access-request to the prepaid 3gpp2 accounting command to stop sending the final online access-request on termination of 3GPP2 prepaid sessions.

> • | Optional commands: If both duration and volume attributes are received, default preference is given to the duration attribute. To set the preference to the volume attribute, enter the following command:

> prepaid 3gpp2 preference volume
> Note that this command alone does not enable pre-paid support. The prepaid 3gpp2 accounting command must be executed as shown to enable pre-paid support.
> If you are using duration-based quota usage accounting, use the following command to define what behavior specifies the end of the billing duration. The default behavior is the duration quota algorithm set to current-time.
> prepaid 3gpp2 duration-quota final-duration-algorithm [ current-time | last-airlink-activity-time | last-user-layer3-activity-time ]
> Note that this command alone does not enable pre-paid support. The prepaid 3gpp2 accounting command must be executed as shown to enable pre-paid support.
> Save the configuration as described in the Verifying and Saving Your Configuration chapter.
> Configuring Pre-paid Billing With Custom Behavior
> This section describes how to enable Pre-paid billing support with custom behavior.
> Important: If RADIUS attributes are present that conflict with the custom pre-paid settings, the values set by the RADIUS attributes take precedence.
> Important: Pre-paid billing support is not available for local subscribers. Even though you can set pre-paid parameters for a local subscriber from the CLI, these settings have no effect on a subscriber session.
> Important: Commands used in the configuration samples in this section provide base functionality to the extent that the most common or likely commands and/or keyword options are presented. In many cases, other optional commands and/or keyword options are available. Refer to the Command Line Interface Reference for complete information regarding all commands.
> Enable custom pre-paid billing for the default subscriber by applying the following example configuration:
> configure
> context <context_name>
> subscriber default
> prepaid custom
> end
> Enable custom pre-paid billing for the default subscriber of a domain alias by applying the following example configuration:
> configure
> context <context_name>
> subscriber name <alias_def_sub>
> prepaid custom
> end
> Notes:

> • | Optional: To have custom pre-paid byte credits based on the flow of compressed traffic, use the following command:

> prepaid custom byte-count compressed

> • | Optional: Set the low-watermark for remaining byte credits. This is a percentage of the subscriber session’s total credits. When the low-watermark is reached a new RADIUS access-request is sent to the RADIUS server to retrieve more credits. To set the low watermark percentage, enter the following command:

> prepaid custom low-watermark percent <percentage>

> • | Optional: Set the time in seconds to wait before sending a new RADIUS access-request to the RADIUS server to retrieve more credits by entering the following command:

> prepaid custom renewal interval <seconds>

> • | Save the configuration as described in the Verifying and Saving Your Configuration chapter.

> 3GPP2 Pre-paid Attributes
> Use the attributes listed in the following table to configure a subscriber for 3GPP2 pre-paid billing;

> Attribute | Sub-attribute | Description
> 3GPP2-Pre-Paid-Acct-Capability |  | This attribute is for setting the prepaid accounting capability.
> | Available-In-Client | The optional Available-In-Client Sub-Type, generated by the PrePaid client, indicates the PrePaid Accounting capabilities of the client in the PDSN or HA and shall be bitmap encoded.
> | Selected-For-Session | The optional Selected-For-Session Sub-Type, generated by the PrePaid server, indicates the PrePaid Accounting capability to be used for a given session.
> 3GPP2-Pre-Paid-Accounting-Quota |  | This attribute specifies the characteristics for PrePaid accounting of the volume and/or duration of a packet data session. It shall be present in all on-line RADIUS Access-Request and on-line RADIUS Access-Accept messages and may be included in other RADIUS Access-Accept messages. Non-used Sub-Types by the PPC and PPS shall be omitted.
> | Quota-Identifier | The Quota-Identifier Sub-Type is generated by the PrePaid server at allocation of a Volume and/or Duration Quota. The on-line quota update RADIUS Access-Request message sent from the PPC to the PPS shall include a previously received Quota-Identifier.
> | Volume-Quota | The optional Volume-Quota Sub-Type is only present if Volume Based charging is used. In RADIUS Access-Accept message (PPS to PPC direction), it indicates the Volume (in octets) allocated for the session by the PrePaid server. In on-line RADIUS Access-Request message (PPC to PPS direction), it indicates the total used volume (in octets) for both forward and reverse traffic applicable to PrePaid accounting13. If a Tariff Switch condition was reached during the session, this Sub-Type contains the complete (before and after) volume used, while the Volume-Used-After-Tariff-Switch attribute contains the volume used after the tariff switch condition.
> | Volume-Quota-Overflow | The optional Volume-Quota-Overflow Sub-Type is used to indicate how many times the Volume-Quota counter has wrapped around 2^32 over the course of the service being provided.
> | Volume-Threshold | The Volume-Threshold Sub-Type shall always be present if Volume-Quota is present in a RADIUS Access-Accept message (PPS to PPC direction). It is generated by the PrePaid server and indicates the volume (in octets) that shall be used before requesting quota update. This threshold should not be larger than the Volume-Quota.
> | Volume-Threshold-Overflow | The optional Volume-Threshold-Overflow Sub-Type is used to indicate how many times the Volume-Threshold counter has wrapped around 2^32 over the course of the service being provided.
> | Duration-Quota | The optional Duration-Quota Sub-Type is only present if Duration Based charging is used. In RADIUS Access-Accept message (PPS to PPC direction), it indicates the Duration (in seconds) allocated for the session by the PrePaid server. In on-line RADIUS Access-Accept message (PPC to PPS direction), it indicates the total Duration (in seconds) since the start of the accounting session related to the Quota-ID.
> | Duration-Threshold | The Duration-Threshold Sub-Type shall always be present if Duration-Quota is present in a RADIUS Access-Accept message (PPS to PPC direction). It represents the duration (in seconds) that shall be used by the session before requesting quota update. This threshold should not be larger than the Duration-Quota and shall always be sent with the Duration-Quota.
> | Update-Reason | The Update-Reason Sub-Type shall be present in the on-line RADIUS Access-Request message (PPC to PPS direction). It indicates the reason for initiating the on-line quota update operation. Update reasons 4, 5, 6, 7 and 8 indicate that the associated resources are released at the client side, and therefore the PPS shall not allocate a new quota in the RADIUS Access-Accept message.
> | Pre-Paid-Server | The optional, multi-value PrePaid-Server indicates the address of the serving PrePaid System. If present, the Home RADIUS server uses this address to route the message to the serving PrePaid Server. The attribute may be sent by the Home RADIUS server. If present in the incoming RADIUS Access-Accept message, the PDSN shall send this attribute back without modifying it in the subsequent RADIUS Access-Request message, except for the first one. If multiple values are present, the PDSN shall not change the order of the attributes.

> ‌
> These attributes can be found in the following dictionaries:

> • | 3gpp2

> • | 3gpp2-835

> • | starent

> • | starent-835

> • | starent-vsa1

> • | starent-vsa1-835

> For more information, refer to the AAA Interface Administration and Reference.
> Pre-paid Attributes
> Use the attributes listed in the following table to configure a subscriber for pre-paid billing;

> Attribute | Description
> SN-Prepaid-Inbound-Octets | If only SN-Prepaid-Inbound-Octets is in the Access-Accept, and the others are not, then the number of outbound credits is infinite.
> SN-Prepaid-Outbound-Octets | If only SN-Prepaid-Outbound-Octets is in the Access-Accept, and the others are not, then the number of inbound credits is infinite.
> SN-Prepaid-Total-Octets | If only SN-Prepaid-Total-Octets is in the Access-Accept, and the others are not, then pre-paid credits is only enforced on the total byte throughput.
> SN-Prepaid-Timeout | SN-Prepaid-Timeout can be used alone or in combination with the other attributes. This integer RADIUS attribute includes a time limit in seconds. Regardless of the values of the Octet counters, the session should send a new authorization request upon timer expiration.
> SN-Prepaid-Watermark | SN-Prepaid-Watermark is optional with any of the attributes. If it is not included it defaults to the CLI default subscriber configuration, which defaults to a value of 10%. This watermark applies to any of the pre-paid attributes being enforced.

> ‌
> These attributes can be found in the following dictionaries:

> • | Starent

> • | Starent-VSA1

> • | Starent-835

> • | Starent-VSA1-835

> • | custom1 through custom9

> Refer to the AAA Interface Administration and Reference for more details.

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