How Mainz University Achieved Scalable BigBlueButton with HD Audio

Challenge

In 2020, during the COVID-19 crisis, Mainz University needed to expand its BigBlueButton infrastructure to support tens of thousands of simultaneous users while ensuring crystal-clear audio quality for effective teaching.

The challenge required expertise in scaling, load testing, and specialized Freeswitch optimization to achieve reliable performance and high-fidelity communication across thousands of concurrent classrooms.

Our Approach

From June 2020 to January 2024, RIADVICE partnered with Mainz University’s Zentrum für Datenverarbeitung (ZDV), the university’s IT and computing center, to consult and support their BigBlueButton environment.

Our contributions included:

• Scaling & resource tuning — advising on cluster optimization and infrastructure adjustments to sustain massive concurrent usage.
• Load testing with bots — simulating large-scale sessions to validate performance across audio, video, and chat before production rollout.
• High-quality audio engineering — conducting extensive research into Freeswitch internals and testing Variable Bitrate (VBR) configurations to achieve 48 kHz stereo audio for significantly improved clarity.
• Dedicated support — providing continuous consulting, including direct phone assistance, to ensure stability and quick resolution of issues.

Once the HD audio optimization was validated at Mainz, the configuration was presented within the Zentren für Kommunikation und Informationsverarbeitung in Lehre und Forschung (ZKI) — the German national consortium of university IT centers. Through ZKI, the improvements were distributed across 70+ German universities, extending the impact far beyond Mainz.

Results

• Supported a peak of 52,848 concurrent users across more than 5,000 simultaneous conferences.
• Delivered 48 kHz stereo audio via Freeswitch, ensuring superior sound quality across lectures and seminars.
• Established one of Europe’s most scalable and resilient BigBlueButton infrastructures.
• Contributed to national adoption of HD audio optimization across the German higher education sector through ZKI.
• Maintained a nearly four-year partnership with Mainz, providing continuous consulting and support.

Why RIADVICE

As a BigBlueButton Certified Service Provider, RIADVICE combined deep technical expertise with long-term commitment, enabling Mainz University not only to scale for crisis teaching but also to shape best practices adopted nationwide.