Metering represents the core of time and volume-based accounting. Service usage is typically measured by performing an accounting of the traffic passing through corresponding subscriber-host queues (volume usage) or by keeping lease-state while the specified subscriber host is connected to the network (time usage).
Statefullness
The accounting information is compared with pre-defined credit expressed in terms of time or volume to monitor service usage.
Sensitivity
Defining so called activity-threshold allows distinction between subscriber-host being connected and subscriber-host effectively using the service. This is particularly of interest in cases of time-based charging.
Accounting information can be reported on per-queue per-sla instance of the specified subscriber. In many situations, a specific level of aggregation (such as a per-subscriber or HSI ingress and egress traffic) is required to perform meaningful mechanism for pre-paid services.