There are two types of quota (credit), volume and time. In volume usage monitoring, the system accumulates byte counters per category-sla-instance and compares it with the assigned quota. After the credit is exhausted (or threshold for renewal is met) the system attempts to renew it with corresponding management system.
In time-based credit, the distinction between active-usage and active-connection is made by defining an activity-threshold, where an object defines an average data rate under which the subscriber-host is considered silent.
If the effective rate of the application usage does not exceed the rate defined by the activity-threshold, the specified subscriber host is considered silent and its corresponding credit is not used. If the application usage exceeds the rate, the application-credit is consumed (in terms of time).