PCEF (Policy and Charging Enforcement Function): PCEF sits in the network, typically in the gateway, and enforces policy decisions and QoS rules determined by the PCRF based on subscriber profiles and network conditions. It directly manages data flow rates, blocks traffic, or applies other policy actions.
Analogy: Imagine PCEF as a traffic controller at an intersection, managing the flow of vehicles based on predefined rules and real-time traffic conditions.
Why It Matters: PCEF is vital for implementing dynamic QoS control, ensuring fair usage, and optimizing network performance based on policy rules.