CHF (Charging Function)

CHF in context

The mobile core is where subscriber sessions, mobility and policy live. In 4G it is the EPC (MME, HSS, S/PGW); in 5G it is the Service-Based Architecture with AMF, SMF, UPF, AUSF, UDM and the NRF. Core exposure is the difference between a single-subscriber leak and a fleet-wide breach.

OSS/BSS platforms (provisioning, charging, mediation, order management) hold the highest-value subscriber and revenue data on the operator side. They are heavily targeted for fraud and insider abuse and are increasingly in scope for regulatory obligations like NIS2 and the UK Telecoms Security Act.

To place CHF in the wider telecom-security picture, review Charging System, QoS, BSF, PCF, Rx Interface and PCRF.

Related terms

• Charging System
• QoS
• BSF
• PCF
• Rx Interface
• PCRF
• DRP
• MNO

Equipment

Policy and charging (PCRF, PCF, CHF, OCS, OFCS)

• Charging System
• OCS
• OFCS
• PCF
• PCRF

Articles in the P1 mobile network security guide

Related topic hubs

• 5G Security 5G SBA, SEPP, SUCI, 5G-AKA, N32 and service-based interface security.
• 5G NEF Security Network Exposure Function security in the 5G core.
• 5G Penetration Testing Pentesting the 5G core, SBA, SEPP, and gNB interfaces.
• 5G Security Training Training on 5G core, SBA, N32, SUCI and radio security.

More from the TelcoSec Glossary

Browse the full TelcoSec Glossary, the Ultimate Guide to Mobile Network Security, or the P1 Arsenal of telecom-security tools.