Table Of Contents
Overview
Information About the Quota Manager
Functionality
System Overview
Network Topology
Quota Indications
Quota Provisioning
Overview
This module provides an overview of the Quota Manager.
Information About the Quota Manager
In versions of the SCMS Subscriber Manager prior to version 3.0.x, there existed functionality to maintain subscriber quota levels across subscriber sessions. This functionality was removed in version 3.0, but has now been enhanced and reinstated.
The Quota Manager (QM) is now available as a component of the Subscriber Manager, which enables Service Control solution providers to manage, with a high degree of flexibility, subscriber quota.
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Functionality
• System Overview
• Network Topology
• Quota Indications
• Quota Provisioning
Functionality
The Quota Manager controls SCA BB quota functionality, and acts as an entry-level quota policy repository. The Quota Manager is an event driven solution leveraging the functionality of the SCE Subscriber API. The Quota Manager provides the following functionality:
•Subscriber quota is preserved across subscriber sessions
•Subscribers can be assigned time-based quota that is replenished in fixed intervals, called aggregation periods
•Subscribers can be moved between packages at any time, whether they are logged in or not
•Subscribers can purchase additional quota within an aggregation period
•Periodic subscriber quota does not accumulate across aggregation periods
•Aggregation periods and amounts can be set on a per package basis
•Quota allocation at the beginning of an aggregation period can be spread over time for different subscribers to avoid the buildup of traffic bursts at the start of the aggregation period
•Subscriber quota is preserved across Quota Manager upgrade
•Supports all SCE topologies (1+1 and MGSCP)
•Supports high availability of the Quota Manager server (utilizing a Veritas Cluster Server)
System Overview
The Quota Manager module runs as a component on the SM. All of the logic to manage and maintain quotas runs on the SM server; therefore, you should configure the Quota Manager on the SM or load the configuration onto the SM. In a cluster setup, you must load the configuration onto each SM in the cluster. Subscriber quotas are stored in the SM DB.
The Quota Manager uses the SCE Subscriber API to provision quota to subscribers upon request using the existing external quota functionality of the SCE.
Note Per package quota configuration must be carried out on the SM adding complexity to the integration or operation. Quota management also requires more management messages on the network.
Network Topology
The following figure shows the network topology of a system employing quota management. The Quota Manager can serve more than one SCE. At any point in time, a single subscriber must be handled by a single SCE.
Figure 1-1 Quota Manager Network Topology
Quota Indications
The Quota Manager is an event-driven component. All quota logic is performed as a response to quota indications that the SCE initiates. Therefore, the quota state is up-to-date in accordance with the last quota indication received.
The Quota Manager handles the following quota indications:
•Quota Breach—The SCE generates this indication when a subscriber uses the entire available quota in the SCE. The quota manager responds to this indication by providing more quota for the subscriber if the subscriber quota allocation is not depleted for the current aggregation period.
•Remaining Quota—The SCE periodically generates this indication to keep the Quota Manager updated with the quota remaining in the SCE. The SCE also generates this indication upon subscriber logout and package switch. In most cases, the Quota Manager does not respond to this indication, but does write the quota value to the database to be stored until the subscriber next logs in. If the reported quota is below zero, the Quota Manager responds by providing more quota for the subscriber if the subscriber quota allocation is not depleted for the current aggregation period.
•Quota Below Threshold—The SCE generates this indication when the subscriber quota in the SCE drops below a predefined level. The Quota Manager responds to this indication by providing more quota for the subscriber if the subscriber quota allocation is not depleted for the current aggregation period.
•Quota State Restore—The SCE generates this indication in response to a subscriber login event. The Quota Manager responds to this indication by updating the subscriber quota in the SCE.
Note Quota calculation uses the system date and time of the Quota Manager machine to calculate aggregation periods. If during Quota Manager operation the system date and time is changed, it is recommended to delete all quota information from the SM database to recalculate all aggregation periods according to the new date and time. This operation will also cause a quota replenish for all subscribers.
Note To remove quota information from the SM database, run the following CLU:
p3subsdb --clear-all-states
Note To support accurate calculation of quota consumption, the Quota Manager stores the last SCE IP that consumed subscriber quota. If the IP address of the SCE changes during the Quota Manager operation, a new dosage will be applied to all subscribers in that SCE. Any quota consumed by the subscriber since the last quota indication before the change of IP address will not be accounted for the subscriber.
Quota Provisioning
The Quota Manager provisions quota to the SCE as a response to the following quota indications: Quota State Restore, Quota Below Threshold, and Quota Breach. Quota provisioning occurs only if quota is still available for the subscriber.
The Quota Manager performs the provisioning by adding quota to the SCE so that after the provisioning operation, the available quota in the SCE will equal a configurable dosage size.
For example, suppose that the following configuration exists for bucket 1:
•Bucket size is 100 MB
•Dosage size is 10 MB
•Threshold size is 1 MB
The following quota provisioning will take place
•When the subscriber logs in for the first time, the SCE initiates a Quota State Restore indication for this subscriber. This indication triggers the following actions:
–100 MB of quota will be added to the Quota Manager database for the first aggregation period
–The Quota Manager provisions only 10 MB of quota to the SCE, as configured by the quota dosage value
•After the subscriber consumes 9 MB of quota, the quota threshold (1 MB) is reached and the SCE initiates a Quota Below Threshold indication for this subscriber. This indication triggers the following actions:
–The Quota Manager provisions a further 9 MB of quota to the SCE. After the provisioning operation, the remaining quota in the SCE equals the dosage size (10 MB).
–At the same time, the Quota Manager will update its database to indicate that 9 MB of quota was consumed by the subscriber. After the provisioning operation, the remaining quota in the Quota Manager is 91 MB (i.e. 100 MB - 9 MB).
Quota provisioning is split into dosages to ensure that quota consumption is accounted accordingly in the Quota Manager database. This ensures that in cases of failures the amount of quota used, but not accounted for, by a subscriber is limited by the quota dosage size.
