Policy Enforcement Overview
The Services Control Gateway enforces Policy and Charging Control (PCC) rules and enhanced PCC (ePCC) rules, which identify how a subscriber’s packets should be treated. A PCC rule or ePCC rule identifies the conditions that the packet must match and the actions that should be taken on the packet.
A PCC rule identifies a service data flow (SDF) filter that the packet must match. An SDF filter can specify:
Source or destination addresses, subnets, and ports
An ePCC rule identifies an application or group of applications that the packet must match. The Services Control Gateway uses ePCC rules rather than 3GPP application and detection control (ADC) rules because ADC rules are not supported by PCRFs with a pre-11 release. The ePCC rules are supported on the Gx interface, which also supports PCC rules.
A PCC or ePCC rule specifies the action to take on packets that match the SDF filter or application. These rule actions can include:
HTTP redirection to a URL or to an IP address (ePCC rules only)
Steering HTTP traffic to an IPv4 or IPv6 address (ePCC rules only)
Steering packets to a routing instance (PCC rules only)
Setting the forwarding class
Setting the maximum bit rate
Performing HTTP header enrichment (ePCC rules only)
Setting the gating status to blocked or allowed
PCC rules and ePCC rules for a subscriber are under either dynamic or static control, depending on the subscriber’s attributes and the configuration you have created.
With dynamic control, PCC rules and ePCC rules are controlled by the PCRF. The PCRF either provisions the rules and sends them to the Services Control Gateway in a Diameter message or sends a message to activate a rule that has been configured on the Services Control Gateway. The PCRF uses the Gx interface to send Diameter messages to the Services Control Gateway.
With static control, there is no input from the PCRF. All static rules must be configured on the Services Control Gateway.