Policy Control Architecture¶

Overview¶

The Policy Control architecture in TelcoAPI follows the 3GPP standards for Policy and Charging Control (PCC). This document describes the key components and their interactions.

Components¶

PCRF (Policy and Charging Rules Function)¶

• Central policy decision point
• Manages QoS and charging rules
• Interfaces with other network elements via Diameter

PCEF (Policy and Charging Enforcement Function)¶

• Enforces policy decisions from PCRF
• Handles traffic detection and QoS enforcement
• Communicates via Gx interface

AF (Application Function)¶

• Provides application-level session information
• Requests specific QoS requirements
• Communicates via Rx interface

Interfaces¶

Gx Interface¶

• Between PCRF and PCEF
• Used for policy rule provisioning
• Supports dynamic QoS control

Rx Interface¶

• Between AF and PCRF
• Used for application-specific requirements
• Enables QoS negotiation

Implementation¶

interface PolicyRule {
  id: string;
  name: string;
  qosParameters: {
    maxBandwidthUL: number;
    maxBandwidthDL: number;
    guaranteedBandwidthUL: number;
    guaranteedBandwidthDL: number;
    qci: number;
  };
  flowInformation: {
    flowDescription: string;
    direction: 'UPLINK' | 'DOWNLINK' | 'BIDIRECTIONAL';
  }[];
  precedence: number;
  active: boolean;
}

Best Practices¶

1. Rule Management
2. Use meaningful rule names
3. Set appropriate precedence

4. Monitor rule usage

5. QoS Control

6. Define clear QoS classes
7. Monitor QoS enforcement

8. Handle QoS violations

9. Performance

10. Cache frequently used rules
11. Optimize rule evaluation
12. Monitor system load

Error Handling¶

enum PolicyError {
  RULE_NOT_FOUND = 'RULE_NOT_FOUND',
  QOS_NOT_AVAILABLE = 'QOS_NOT_AVAILABLE',
  INVALID_PARAMETERS = 'INVALID_PARAMETERS',
  SYSTEM_ERROR = 'SYSTEM_ERROR'
}

interface PolicyErrorResponse {
  error: PolicyError;
  message: string;
  ruleId?: string;
  timestamp: string;
}

Monitoring¶

Monitor these key metrics: - Rule installation success rate - QoS enforcement accuracy - Policy decision latency - System resource utilization

References¶

1. 3GPP TS 23.203: Policy and charging control architecture
2. 3GPP TS 29.212: Policy and Charging Control over Gx reference point
3. 3GPP TS 29.214: Policy and Charging Control over Rx reference point