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Modern tools for TTCN-3

ntt gives you the tools you need to write tests efficiently.

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ntt is a free and open application stack for testing with TTCN-3. It’s the incarnation of its closed source predecessor k3. It builds upon 15 years of experience of running production workloads at Nokia. ntt is designed with low latency and high fidelity appliances in mind. Current releases include:

ntt is still a young project, so we do not provide a TTCN-3 compiler, runtime or any open ASN.1 tools, yet. If you need such, we recommend Titan! Titan offers a mature compiler and runtime with an extensive set of adapters and modules.

What’s TTCN-3?

TTCN-3 is a standardized domain-specific language for scripting tests. It supports various types of testing and is a good addition to unit tests. Despite being clearly from the last millennium, TTCN-3 offers some excellent features for testing protocols and services:

  • native support for concurrency and alternate code flows (similar to Go).
  • a powerful matching mechanism. Think supercharged regular expressions for arbitrary data types.
  • and it’s language agnostic: Adapters and codecs are implemented in any language you see fit. So you can leverage any ecosystem you need.

What’s the project status?

ntt is used in production by Nokia in 4G and 5G. But still, consider this software unstable. Like in every young project features need time to settle and not all parts have the same test coverage, yet. ntt is no exception. Also, consider ntt experimental as we are exploring new ways of working with TTCN-3.

ntt has full support for TTCN-3 version 4.10.1 and understands most parts of the standardized extensions for documentation comments, performance and real-time testing, advanced parameterization, behaviour types, as well as various extensions from Titan and k3.


Our major goal is to improve the TTCN-3 user experience by providing modern tools and by establishing best practices for working with TTCN-3 test suites. We will also continue updating ntt for the latest TTCN-3 standards and will be adding one or the other feature.
But our focus is on advanced IDE support first and your feedback can help us to achieve this goal.

We plan on finishing goto-definition first and then we’ll implement initial diagnostics.

Call for Contributors

As a new project, we have plenty of room to grow and many plans we want to execute. If you want to report a bug, or if you are a developer, tester, designer, DevOps, documentation enthusiast or think you can and want to join ntt, we want you with us! Read more about becoming a contributor in our contribution guide.

Contact us

If you have any questions you are very welcome to contact us at


ntt is distributed by an BSD 3-clause license.