SoftSwitch Billing platform for 20,000+ subscribers — Vietnamese public-sector tender (2025)
End-to-end charging, rating, invoicing and self-care platform for an internal SoftSwitch serving 20,000+ subscribers at a major Vietnamese public-sector body; built to public-sector security and audit requirements, integrated with existing SoftSwitch CDR and finance systems. Client identity withheld under NDA.

Challenge → Solution → Outcome
Step-by-step view of how we moved from the brief to the outcome.
A major Vietnamese public-sector body needed a domestically-built Billing platform for an internal SoftSwitch serving 20,000+ subscribers across nationwide units. Hard requirements: on-premise deployment, full CDR reconciliation against the SoftSwitch, configurable tariffs for internal vs external traffic, official e-invoicing and a hardened audit trail meeting public-sector standards.
Problem. Solution. Result.
A major Vietnamese public-sector body needed a domestically-built Billing platform for an internal SoftSwitch serving 20,000+ subscribers across nationwide units. Hard requirements: on-premise deployment, full CDR reconciliation against the SoftSwitch, configurable tariffs for internal vs external traffic, official e-invoicing and a hardened audit trail meeting public-sector standards.
- 01Designed a modular Billing architecture: Mediation → Rating → Charging → Invoicing → Self-care.
- 02Mediation layer parses SoftSwitch CDRs in near real-time and persists to a tamper-evident store.
- 03Rule-based rating engine supports per-unit, peak/off-peak, internal vs external destination, and time-bound campaigns.
- Won the public-sector tender in 2025 against incumbent vendors.
- 100% CDR-to-invoice reconciliation in pilot — zero dispute on the first billing cycle.
- Self-care portal lets each unit self-check usage and invoices, removing manual finance back-and-forth.
Solution
- 01Designed a modular Billing architecture: Mediation → Rating → Charging → Invoicing → Self-care.
- 02Mediation layer parses SoftSwitch CDRs in near real-time and persists to a tamper-evident store.
- 03Rule-based rating engine supports per-unit, peak/off-peak, internal vs external destination, and time-bound campaigns.
- 04Postpaid + prepaid hybrid charging with credit control; daily, monthly and ad-hoc billing cycles.
- 05Compliant e-invoicing integrated with the General Department of Taxation gateway.
- 06Hardened deployment: on-premise, network-segregated, signed audit log, role-based access for finance/operators/auditors.
Outcome
- Won the public-sector tender in 2025 against incumbent vendors.
- 100% CDR-to-invoice reconciliation in pilot — zero dispute on the first billing cycle.
- Self-care portal lets each unit self-check usage and invoices, removing manual finance back-and-forth.
- Architecture extensible to add new SoftSwitch nodes and new charging models without code change.
Measurable shift
Inside the engagement

The team understood both telecom signalling and public-sector procurement reality. The design held up through every clarification round of the tender.


