SAE Accounting

The router and the SAE generate RADIUS accounting records when subscribers access the Internet and use value-added services. The records are sent to RADIUS accounting servers and are logged in accounting log files, or they are sent to accounting flat files. External systems collect the accounting log files and feed them to a rating and billing system.

The SRC module allows a variety of accounting deployments. This topic shows the standard deployment that we supply, a second option that does not depend on a RADIUS server, and a third option in which customers develop their own deployment by choosing a CORBA plug-in.

In the standard SRC deployment (see Figure 1), the router and the SAE are clients of the RADIUS accounting server. They pass subscriber accounting information to a designated RADIUS accounting server in an accounting request. The RADIUS accounting server receives the accounting request and creates accounting log files.

The SRC module works with other AAA RADIUS servers; however, we validate the SRC module only with Merit, Interlink RAD-Series AAA RADIUS Server, or Juniper Networks Steel-Belted Radius/SPE server.

Figure 1: Sending Accounting Data to a RADIUS Server

A second option, shown in Figure 2, uses an accounting flat file generated directly by the SAE, without a RADIUS server.

Figure 2: Sending Accounting Data to an Accounting File

Figure 3 illustrates a third possibility, one in which the customers use a CORBA plug-in of their own choice.

Figure 3: Customer Choice for SRC Accounting Deployment

Accounting Policy

The SAE defines the policies that control the network traffic for the subscriber based on the subscriber’s subscriptions. It also determines the accounting statistics collected for the subscribed service.

While defining the policies for a service, the SAE can choose the policy rules to be used for accounting per interface direction (ingress and egress). Statistics are collected for the chosen policy rules for the service and are sent to the RADIUS accounting server. The SAE can also decide not to collect any policy rule-specific statistics for the service. In this case, only session times are sent to the accounting system when the service is deactivated. When choosing multiple policy rules on traffic direction for statistics collection, the SAE summarizes the statistics by adding the individual values.

The SRC software allows you to enable or disable the accounting-per-attachment feature to calculate accounting for each individual policy list on the basis of the accounting flag status of each policy rule in the policy list. This capability optimizes the creation of statistics for the policy list. When the accounting-per-attachment feature is enabled for a policy list, accounting statistics are calculated per policy list only if the accounting flag is enabled on any one of the policy rules in that policy list. If the accounting flag of all policy rules in the policy list is disabled, the accounting statistics are not calculated for all policy lists even though the accounting-per-attachment feature is enabled. When the accounting-per-attachment feature is disabled for a policy list, accounting statistics are not calculated per policy list irrespective of the accounting flag status of all policy rules in that policy list. By default, the accounting-per-attachment feature is not set. If the accounting-per-attachment feature is not configured, the accounting statistics are calculated for all policy lists irrespective of the accounting flag status of all policy rules in that policy list.

Any change in the enabling or disabling of the accounting-per-attachment feature takes effect only after the sscc connection is restarted. After you restart the sscc connection, accounting statistics are calculated for the updated policy list on the basis of the configuration of the accounting-per-attachment feature. Accounting statistics are calculated when the policy list is attached to an interface or subscriber.

When the attached policy list is changed, the SRC software sends a new policy attachment message containing the recalculated accounting-per-attachment statistics flag to the subscriber who uses the policy list. If the policy list is shared by subscribers, then the SRC software sends a new policy attachment message containing the recalculated accounting-per-attachment statistics flag to all subscribers who use the policy list. The policy list attached to the interface or subscriber can be changed for the following reasons:

• Policy structure change made by the administrator

• Activation or deactivation of manual services

Table 1 lists cases for the collection of various accounting information based on the accounting-per-attachment feature for previous policy lists attached to the interface or subscriber.

Table 2 lists cases for the collection of various accounting information based on the accounting-per-attachment feature.

Subscription Process

After an outsourced service has been set up, subscribers can order primary access or value-added services from retailers, who in turn notify the wholesaler of the new end subscription. Conversely, accounting data is collected by the wholesaler and communicated to the retailer to provide enough data for the retailer to bill the subscriber.

The overall subscription process is simplified:

• The subscriber has no need to interact with another party or a device other than the router.

• When the subscriber goes to the Web portal and selects the service, the subscription activation is triggered.

• The subscriber’s portal page adjusts to display the new service.

• Accounting data is generated, identifying the service being tracked for the subscriber.

Tracking Subscriber Sessions

The intelligent service accounting function of the SRC module tracks the subscription activity for each subscriber and each service session. It collects usage information and passes the information to the appropriate rating and billing system.

Multiple service sessions can be activated simultaneously for a subscriber and can be tracked separately from an accounting standpoint.

Events are generated when service sessions are activated and deactivated, and during interim accounting updates.

Accounting Plug-Ins

Plug-ins allow service providers to easily extend the capabilities of their systems through the use of plug-in software. See SAE Plug-Ins.

Interim Accounting

The router and SAE generate interim accounting records for broadband primary services (through PPP) and value-added services, respectively. RADIUS servers log the interim records in their accounting log files when interim accounting is enabled.

The external rating system calculates the charges by using interim records instead of stop records for timeout sessions. The calculation occurs when the last record is interim and for open sessions whose last record at the end of a billing cycle is interim.

An accounting interim interval is defined for each service and applied to all subscriptions to that service. The router and SAE generate accounting requests with a status of interim for every period of time specified with the interim value.

The router receives an accounting interim value for a session through a RADIUS server when the router makes an authentication request. If the RADIUS server does not provide a value, then the router does not generate interim accounting records.

The SAE obtains an accounting interim value from the directory. When the accounting interim value is not stored, the SAE uses global values. When a value equals zero, the SAE does not generate interim accounting records.