Volume quota can be provided per UE using the RADIUS attribute Alc-Credit-Control-Quota. For DSM, the time quota of the attribute is not supported and must be zero. The quota categories are non-configurable and must be either soft or hard. Upon exhaustion of hard quota the UE is immediately disconnected.
The following non-configurable quota categories are supported:
hard quota
When a hard quota is exhausted, the UE is immediately disconnected.
soft quota
When a soft quota is exhausted, the WLAN-GW can apply several actions:
Send a triggered RADIUS Accounting Interim Update with the reason WLAN-Quota-Exhausted, if enabled under the configure aaa isa-radius-policy name acct-update-triggers soft-quota-exhausted context.
Apply a filter configured under the vlan-tag-ranges range range distribute-sub-mgmt soft-quota-exhausted-filter context. The filter replaces any previous filter applied to the UE. If the soft quota is extended by a CoA message, the filter is reverted to the previously applied filter for that UE.
Both soft and hard quotas can be independently extended by means of CoA messages, using the same attribute. Quotas received in a CoA message are only enforced from that moment onward and none of the UE traffic before the CoA message counts toward the new quota. This supports flexible combinations of hard and soft quotas, for example:
Apply soft quota close to hard quota to offer some grace period before the session is terminated. During this grace period, the UE is notified when nearing quota exhaustion using an HTTP redirect installed by the soft-quota-exhausted-filter command and can buy new credit. After the UE buys new credit, a CoA message updates both hard and soft quota.
Apply hard quota as the real limit but use soft quota to automatically trigger accounting updates instead of rely on periodic interim updates; for example, for each 5% of volume consumed. Upon each interim update, a CoA message is sent that resets only the soft quota and generates a new report.
Apply hard quota as the real limit but use the soft-quota-exhausted-filter command (configure service ies/vprn subscriber-interface group-interface wlan-gw vlan-tag-ranges range distributed-sub-mgmt) to redirect to an advertisement page, for each amount of volume consumed. After the advertisement has been shown, a CoA message extends the soft volume to remove the filter again.
By default, quota is enforced on the combination of upstream and downstream traffic. This can be changed to only upstream or only downstream using the volume-quota-direction command in the vlan-tag-ranges range range distribute-sub-mgmt volume-quota-direction context.