Question: In a Policy and Charging Control (PCC) architecture, how do a PCRF (Policy and Charging Rules Function) and a PCEF (Policy and Charging Enforcement Function) advertise support for the Gx interface after establishing a transport connection?
Option 1: By sending a dedicated Gx Initialization Message
Option 2: Through the inclusion of specific values in the Auth-Application-Id AVP and Vendor-Id AVP within HTTP headers
Option 3: By including the application identifier in the Auth-Application-Id AVP and the 3GPP Vendor-Id (10415) in the Vendor-Specific-Application-Id AVP of Diameter Capabilities-Exchange messages
Option 4: Via a separate TCP handshake specifically for Gx
Explanation: In the context of PCC, specifically for the Gx interface, the initialization and maintenance processes rely on standard Diameter protocols. The correct advertisement of Gx support between PCRF and PCEF is achieved through the exchange of Capabilities-Exchange messages, which are part of the Diameter Base Protocol. These messages must contain specific identifiers: the application identifier in the Auth-Application-Id AVP and the 3GPP Vendor-Id (10415) in the Vendor-Specific-Application-Id AVP. This process ensures that both nodes are aware of each other’s capabilities regarding the Gx interface, facilitating effective policy and charging control in telecom networks.