Viettel's Innovative Cloud-Native Charging System Impressively Migrates 100 Million Subscribers with Zero Downtime

Viettel Achieves Major Milestone in Subscriber Migration

In a remarkable leap for telecommunications, Viettel High Technology Industries Corporation, part of the Viettel Group, has successfully transitioned over 100 million subscribers and around 5,000 tariff plans to its proprietary cloud-native charging system, vOCS 4.0. This monumental achievement took just three months and was accomplished without experiencing any service interruptions, a feat that distinguishes Viettel as a leader in the Asian telecom sector.

The process of replacing a charging system is often regarded as one of the riskiest endeavors for telecom operators due to the potential for extensive service outages. However, Viettel High Tech took significant measures to mitigate these risks. Utilizing real-time data synchronization, parallel operations, and a phased migration approach, the team ensured a seamless transition. Furthermore, they implemented an instant rollback feature at each stage, reinforcing reliability throughout the migration.

Their innovative approach garnered recognition at the 2026 Telecom Review Excellence Awards, where Viettel was honored with the award for Best Technology Deployment in Asia. This accolade marks a significant milestone, being the first time a Vietnamese company has received such an honor in the telecom industry.

The Impact on Operators

Viettel’s new charging system, vOCS 4.0, enables operators to process over 300,000 transactions every second with a latency of less than 5 milliseconds. This is applicable to their 2G, 3G, 4G, and 5G services, as well as fixed line offerings, all from a single, unified platform. Importantly, the new system allows for a reduction of hardware investment by up to 50% compared to previous generations, allowing for shared infrastructure across the network.

In addition to cost savings, the platform brings agility into the operational process; new tariff plans can be created in hours rather than days, and the rollout of new features occurs three times faster than in prior systems. Projects that would have taken weeks can now be expedited, significantly increasing the company's efficiency.

A resilient architecture supports this next-generation solution, featuring data centers that are approximately 2000 kilometers apart and the ability to automatically recover in under two minutes from any disruptions. This level of performance ensures that Viettel can keep its commitment to providing uninterrupted service to customers, a promise that is critical in today's fast-paced digital environment.

Building Local Expertise

The development of vOCS 4.0 is a noteworthy achievement as it shifts the telecom industry landscape. Rather than relying on international vendors, Viettel developed every core element of the platform in-house, from the telecom-grade cloud-native environments to network function virtualization and real-time charging management. This strategic move aims not only to enhance digital sovereignty but also to improve operational flexibility for the company.

Luu Manh Ha, CEO of Viettel Networks, emphasized the significance of maintaining independence from foreign suppliers by owning their charging system. He remarked, “Owning the charging system means an operator is not dependent on foreign vendors—it safeguards digital sovereignty and preserves business flexibility.”

Nguyen Minh Quang, CEO of Viettel High Tech, articulated the ambition of the new platform stating, “The charging system is where an operator's business strategy manifests into real-time revenue. We believe vOCS 4.0 is positioned to help operators globally capitalize on the opportunities presented by 5G and digital services.”

Since its inception in 2017, when vOCS 4.0’s predecessor, vOCS 3.0, replaced a foreign platform for 90 million Viettel subscribers, the technology has already served over 220 million subscribers across 11 countries. Now, as Viettel High Tech extends vOCS 4.0 to operators across the globe, the expectation is set high for what this game-changing technology can achieve in the future.