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Configuring ISG Support for Prepaid Billing
Information About ISG Prepaid Billing Support
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reauthorization. During reauthorization, the prepaid billing server may provide ISG with an additional
quota if there is available credit. If no further quota is provided, ISG will log the user off from the service
or perform some other specified action.
When a service is deactivated, the cumulative usage is provided to the prepaid billing server in an
Accounting-Stop message.
ISG Prepaid Volume Monitor Polling Timer and QV Values
The Cisco IOS prepaid volume monitor polling timer determines when ISG will initiate a prepaid
reauthorization. The polling timer value is (15 seconds < polling-monitor-time < 300 seconds). This
value is calculated dynamically based on the QV value (which defines the volume-based quota), the
actual rate, and the configured volume threshold. The prepaid volume monitor polling timer is not
directly configurable.
To avoid allocating more volume quota than the subscriber is entitled to during the first authorization
(when usage rate is unknown), the QV value should be a minimum of (15 x access rate). In cases in which
the usage rate is known, the QV value should be at least (15 x usage rate).
In cases in which the input access rate is much higher than the QV value, it is recommended that the
correct QV value be calculated using the following formula: access rate x 15 > QV < access rate x 300.
For example, an ADSL2 or VDSL user access-rate can be up to 20 Mbps. That is approximately
2.5 megabytes (MB) of data in one second. Calculate the QV value by using the following formula:
2.5 MB x 15 seconds > QV < 2.5 MB x 300 seconds. This calculation results in a QV value between
37.5 MB and 750 MB, however we recommend you do not choose either the highest or lowest value in
this range. For example, you might pick a value of QV = 100 MB.
ISG Prepaid Threshold
By default, ISG sends reauthorization requests to the billing server when a subscriber’s quota is
exhausted. ISG prepaid thresholds allow ISG to send reauthorization requests before a quota is used up.
When a prepaid threshold is configured, ISG sends a reauthorization request to the billing server when
the amount of remaining quota is equal to the value of the threshold. Prepaid thresholds can be
configured for both time and volume.
For example, if the prepaid threshold is configured for 10 seconds, and the prepaid billing server sends
ISG a quota of 30 seconds, ISG will send a reauthorization request to the prepaid billing server when the
subscriber has used up 20 seconds of the quota and has 10 seconds remaining.
ISG Prepaid Idle Timeout
The ISG prepaid idle timeout can be used to suspend a prepaid service session if no traffic is received
for a specified period of time. ISG keeps the session up during the suspension but releases all quota
previously received for the prepaid session. Subsequent traffic on the session will cause ISG to send a
reauthorization request and download a new quota for the session.
Summary of Contents for IOS XE
Page 14: ...About Cisco IOS XE Software Documentation Additional Resources and Documentation Feedback xii ...
Page 28: ...Using the Command Line Interface in Cisco IOS XE Software Additional Information xiv ...
Page 36: ...Intelligent Services Gateway Features Roadmap 8 ...
Page 46: ...Overview of ISG Feature Information for the Overview of ISG 10 ...
Page 70: ...Configuring ISG Control Policies Feature Information for ISG Control Policies 24 ...
Page 136: ...Configuring MQC Support for IP Sessions Feature Information for MQC Support for IP Sessions 8 ...
Page 224: ...Configuring ISG Subscriber Services Feature Information for ISG Subscriber Services 20 ...
Page 344: ...Service Gateway Interface Feature Information for Service Gateway Interface 8 ...