Initial Quota Determination

The initial quota determination (IQD) includes an estimated quota and validity time (QVT) for each request for a quota, based on the service configuration and on the velocity of quota consumed between earlier requests.

Adaptive Quota Management (AQM) makes an initial quota determination using the historical quota consumption velocity and quota management attributes in the service type definition. IQD does not consider impacts to balances or meters, or any other sessions, services, contexts, groups, subscribers, or devices.

Figure 1 shows the IQD process flow.
Figure 1. IQD Process
IQD Process Diagram
  • Quota Consumption Velocity

    For data, this is the rate at which data is used. In general, when authorizing quota, a flow that requires a larger allocation (for example, 2MB per minute) is authorized to have more quota than a flow that requires a smaller allocation (for example, 1MB per minute).

  • Service Type Attributes
    • AQM Enabled.
    • Minimum and Maximum Quota Amount.
    • Minimum, Default, and Maximum Quota Validity Time (QVT).

AQM uses a minimum quota value when:

  • The quota velocity is unknown.
  • The balance velocity is unknown.
  • The balance velocity indicates it is near a balance threshold.

In these situations, the minimum quota value can be the configured min_auth or the calculated minimum, which is the product of the quota velocity and the min_quota_validity_time. The adaptive_threshold_always_use_min_auth parameter indicates which minimum value to use. When this parameter is set to true or when the quota velocity is unknown, the min_auth value is used. When the parameter is set to false (the default) and the quota velocity is known, the greater of the two values is used.

When authorizing across a time change into a new balance or meter for which the quota velocity is unknown, the adaptive_threshold_use_min_auth_after_time_change parameter determines the AQM behavior. If adaptive_threshold_use_min_auth_after_time_change is true (default), AQM uses the min_auth value and TTC is not set. If false, the quota can drop below any configured minimums to meet the threshold and TTC is set.
Note: For a shared balance where the overall velocity is significantly larger than the individual velocity, the threshold can appear more distant than it is. In this situation, it is important to set the threshold scale factor to account for the larger velocity. For more information about setting the threshold scale factor, see the discussion about balance threshold feedback in MATRIXX Diameter Integration.

For a complete description of the service type attributes, see the discussion about AQM configuration in MATRIXX Diameter Integration.