AS Session QoS Modification

When the REST QoS plugin receives a traffic plane notification (for example, transmission resource lost), or if it gets informed that the Rx session is terminated (for example, due to a release of PDN connection), then it sends an HTTP POST message including the notified event (for example, session terminated) and the accumulated usage (if received from the PCRF) to the callback URI notificationUri provided by the SCS/AS during the creation of the individual AS Session with the Required QoS Subscription. The SCS/AS responds with an HTTP response to confirm the received notification.

Figure 2-33 illustrates the event notification generated when a PCRF terminates the Rx session. In this case, PCRF sends a Rx-ASR command to the REST QoS service plugin. The QoS service plugin then triggers a notification toward the QoS action, which verifies if the session exists in the database. Once the session data is fetched from the database, a notification is sent to the SCS/AS with details of the event. After a response is received from the SCS/AS, an unregister notification request is sent to the REST QoS plugin to stop sending notifications for this UE. The session data in the database is then cleared.

Figure 2-33 AS Session QoS Modification