Converged Charging Function
3GPP-compliant Converged Charging System supporting online and offline charging for 5G service-based architecture.
Nchf — HTTP/2 + JSON — Service-Based Architecture
One Function, All Charging Modes
CHF replaces separate online and offline charging systems with a single converged function
4G Era
Separate OCS for online and OFCS for offline. Dual integration, dual maintenance, dual complexity.
- Two systems to deploy
- Diameter Ro + Rf interfaces
- No native 5G support
5G Era — CHF
Single function handles online quota management and offline CDR generation in the same session.
- One platform, all modes
- Nchf SBI — HTTP/2 + JSON
- Cloud-native, NRF-discoverable
5G Service-Based Architecture
CHF at the center of the charging ecosystem — every 5G network function connects via Nchf
SMF — Session Mgmt
PDU session charging with QoS flow awareness
AMF — Access Mgmt
Registration, mobility, and N2 connection events
SMSF — SMS Function
SMS submit and deliver charging events
PCF — Policy Control
Spending limit control and policy counters
NRF — Repository
Service discovery and CHF instance selection
Real-Time Charging, Simplified
From service request to revenue capture — CHF processes every transaction with carrier-grade speed and precision
Real-Time Authorization
Every voice call, data session, or SMS is authorized instantly against the subscriber's balance — before the service begins. No overspend, no revenue leakage.
Continuous Quota Management
Usage is tracked in real time throughout the session. Quota is dynamically allocated as needed, with policy rules enforcing fair usage and spending limits.
Accurate Revenue Capture
The moment a session ends, CHF generates a complete charging record and immediately triggers billing. Every byte, every second, every event is accounted for.
Cloud-Native by Design
Built for containerized deployment — every CHF instance is stateless, discoverable, and independently scalable
Containerized
Docker images, Helm charts, Kubernetes operators — deploy anywhere from bare metal to public cloud
Stateless Design
Session state stored in distributed cache, not local memory. Any node can handle any request
NRF Service Discovery
CHF registers with 5G NRF at startup. NFs discover CHF dynamically — no hardcoded endpoints
Horizontal Scale
Add CHF instances during traffic peaks. NRF load-balances across instances. Scale down when idle
GitOps Ready
Declarative configuration in Git. CI/CD pipeline for zero-downtime rolling updates and canary deployments
From Diameter to Nchf — The 5G Transition
CHF supports both legacy and 5G interfaces, enabling a phased migration without service disruption
Diameter Gy/Ro interfaces for online charging in EPC and IMS networks
CHF exposes both Diameter (4G) and Nchf (5G) — one platform, two protocol stacks
Full Nchf SBI with HTTP/2 + JSON. Network slice-aware, NRF-discovered, converged online+offline
All subscribers migrated to converged CHF. Legacy OCS/OFCS decommissioned. Single charging platform
Frequently Asked Questions
How is CHF different from traditional OCS?
CHF is the 5G evolution of OCS. It converges online and offline charging into a single function, uses HTTP/2 + JSON (Nchf SBI) instead of Diameter, is cloud-native and stateless, and supports network slice-aware charging. OCS handles only online charging in 4G networks via Diameter Ro/Gy.
Can CHF work alongside existing 4G OCS?
Yes. CHF can operate in dual-stack mode, exposing both Diameter Gy/Ro for 4G EPC/IMS traffic and Nchf for 5G SA traffic. This enables a phased migration — operators can consolidate onto CHF gradually without disrupting existing services.
What makes CHF cloud-native compared to legacy charging?
CHF is designed as a stateless, containerized microservice. It registers with NRF for dynamic discovery, stores session state in distributed cache (not local memory), scales horizontally via Kubernetes, and supports GitOps-based CI/CD for zero-downtime deployments. Legacy OCS typically runs as a stateful monolithic application on dedicated hardware.
Full-Stack Technology for Your Telecom Business
ZBensoft integrates charging, core network, and AI capabilities to help operators run efficiently and grow sustainably.
Request a Demo