Terabit networks move from vision to live deployment at TNC26

What began as a vision and a series of enthusiastic discussions is now becoming a reality: a terabit network designed, built, tested and deployed in practice. This is no small feat, considering that many of the technologies involved are only just emerging and are not yet widely adopted.

The network jointly designed by CSC, GÉANT, NORDUnet, SUNET and SURF, and enabled by HPE Networking, connects infrastructure across Amsterdam, Copenhagen, Stockholm and Helsinki. Spanning distances of up to 1,150 kilometers between sites and delivering up to 1.6 terabits per second of capacity, it represents a cross-continental network operating at an unprecedented scale. The network is demonstrated in a high-demand, real-world event environment at TNC26, taking place June 9–11, 2026, at Musiikkitalo in Helsinki, Finland.

From test environments to real-world implementation

Building a functional terabit network outside controlled test environments is inherently complex. Many of the technologies used are only now entering the market, and several components remain in early stages of maturity or are not yet fully ready for large-scale deployment. Because of this, the project team had to work around limitations while integrating equipment that is effectively ahead of the current commercial curve.

“Running a cross-continental, terabit-scale network in a live environment is a significant step for the research and education community. It demonstrates that next-generation networking capabilities are now ready to support real-world scientific and data-intensive workloads. We’re proud to contribute to this collaborative effort, working alongside leading research networks to help turn emerging technologies into practical infrastructure that can support the next wave of innovation.” says Dobias Van Ingen, VP & CTO of HPE Networking EMEA.

The project is part of a broader transition already underway: preparing research and education networks for the terabit era. Rather than treating the initiative as a standalone experiment, the partners designed it as a practical example of a next-generation networking infrastructure capable of supporting the rapidly growing demands of artificial intelligence, modeling, and large-scale simulations.

“The sheer scale of the network has made the project unique and exciting. Making sure all the connections work and getting the technology needed has required close coordination and continuous problem-solving across all parties.” tells Jani Myyry, Senior Network Architect at CSC. “Hosting TNC26 has provided a unique opportunity to demonstrate how collaboration across organizations can turn emerging technologies into real-world capability.”

The deployment reflects a broader evolution in network architecture, from the shift toward coherent pluggable technologies in routers to faster innovation cycles and the growing adoption of capabilities originally developed for AI-scale hyperscaler networks across the backbone.

A shift in how networks are built

At the same time, the project highlights how much work still remains. While many next-generation capabilities appear production-ready on paper, real-world deployment tells a more nuanced story. The network operates at distances and performance levels close to the physical limits of current optical and routing technologies. Reaching the terabit era is proving to be as much about overcoming physical constraints as it is about advancing technology.

Despite these challenges, the network built for TNC26 is operational and is demonstrated under production conditions. This means that terabit-era networking can be deployed, tested and validated in real-world environments, even as the broader ecosystem continues to mature.

Such a deployment is only possible when all participating organizations already operate modern, high-performance networks. It requires advanced optical backbone infrastructure, high levels of operational readiness, and long-term investment in network development. And a lot of hard-core expertise to make this reality.

In several regions, this foundation is already well established. Rather than building entirely new systems, the approach relies on interconnecting existing, high-capacity networks, creating a larger, more powerful whole.

“At GÉANT, we are thrilled to be working with NORDUnet, SUNET, SURF and CSC on something this ambitious. Seeing terabit connectivity proven end-to-end is a powerful demonstration of what our community can achieve together. GÉANT’s backbone, upgraded with Nokia, has given us the foundation to support trials like this one.” said Bram Peeters, Chief Network Services Officer from GÉANT. “And this is only the beginning: with AI-driven programmes, like the EuroHPC HyperConnectivity project, placing higher demands on our infrastructure, research and education networks must be terabit-ready. Together, we are making sure this happens.”

“Terabit networking has become a requirement for demanding customers”, says Lars Lange Bjørn, head of Network and Services Technology at NORDUnet. “We are active preparing the deployment for HyperConnectivity for EuroHPC across the Nordic countries. TNC26 is a great opportunity to showcase these new capabilities not just in our network, but across Europe in cooperation with our colleagues”.

“SUNET’s focus on designing Sweden’s national research and education network for the highest possible signal quality has served our research goals well, and is now proving capable of carrying terabit speeds farther than expected without regeneration. What makes this equally significant is that we didn't need to build anything new to get there: the network devices were provisioned using our standard SUNET and NORDUnet automation tooling, integrated directly into the existing research network.”, tells SUNET’s Senior Network Architect Magnus Bergroth.

"At SURF we are always interested in testing the full potential of networking technology together with our Nordic partners. With this trial we are excited to learn about the limits of the 800G OpenZR+ technology since OpenZR+ is the basis for the next generation of our national SURF network that we are currently rolling out." tells Arno Bakker, Senior Network Specialist at SURF.

More information: Juha Oinonen, Director, Funet services, juha.oinonen(at)csc.fi, p. +358 50 381 9513