A generic use case for flow-based dynamic policy is related to customized network level treatment of on-demand services. Such services can represent a wide range of applications, such as video-on-demand or access to a specific application in the network. The service can be identified by traffic destination parameters or DSCP bits. After the service is identified, a set of actions can be applied to the service (rate change, forwarding-class change, Usage-Monitoring, and so on).
Typical flow of events for service activation is shown in Figure: Generic use case for IP criterion-based policy change via Gx:
1) An established user subscribes to a service in the network via a Web portal at any time.
2) After the authentication/payment is accepted, the back end (for example, the Web portal integrated in OSS) identifies the service and submits the parameters defining the network delivery of the offered service to the PCRF.
3) The PCRF converts those parameters into rules and submits those rules to the subscriber-host on the BNG via the Gx. The rules identify the service on the network level (destination IP@ and port) along with the needed action.
4, 5, and 6) Before the service can be started, the action of individual policy management elements must be acknowledged to ensure that the resources for the service delivery are available and instantiated before the service is delivered to the subscriber.
7) The service traffic can be started from the subscriber side. Network requirements for the successful service delivery are enforced on a per flow or DSCP basis as defined by the PCC rule.