HANOI – October 27, 2026 -- Viettel High Technology Industries Corporation has migrated more than 100 million subscribers and about 5,000 tariff plans at Viettel, Vietnam's largest mobile operator, to its in-house cloud-native charging system vOCS 4.0. The three-month cutover ran on a live national network with no service disruption.
Phased cutover with instant rollback limits the risk of replacing a charging system
Replacing a charging system is one of the riskiest projects an operator can undertake, and many operators therefore stay on legacy platforms. Viettel High Tech, part of Viettel Group, reduced the risk through real-time data synchronization, parallel running and a phased cutover, with instant rollback at every stage.
vOCS 4.0 processes more than 300,000 transactions per second at latency below 5 milliseconds
- Scale: 2G to 5G and fixed services run on one platform.
- Cost: Hardware investment falls by up to 50% against the previous generation, because infrastructure is shared with the network.
- Agility: New tariff plans take hours instead of days. New features arrive three times faster and deployments are about 30% faster.
- Resilience: Two active data centers sit about 2,000 km apart, with automatic recovery in under two minutes.
Project wins Best Technology Deployment in Asia, a first for a Vietnamese company
The deployment took the Telecom Review Excellence Awards 2026 prize in that category.
Viettel High Tech built every core layer in-house to cut dependence on foreign vendors
The company developed a telecom-grade cloud-native platform, NFV-MANO orchestration, real-time charging, and subscriber and balance management. Luu Manh Ha, CEO of Viettel Networks, which operates the system on Viettel's network in Vietnam, said owning the charging system means an operator is "not dependent on foreign vendors." He tied this to digital sovereignty and business flexibility.
Nguyen Minh Quang, CEO of Viettel High Tech, said vOCS 4.0 is ready to help operators worldwide capture the value of 5G and digital services.
The predecessor, vOCS 3.0, replaced a foreign vendor's platform for 90 million Viettel subscribers in 2017. Across both generations, vOCS serves more than 220 million subscribers in 11 countries. Viettel High Tech now offers vOCS 4.0 to operators worldwide.