About TOSSI

TOSSI - the Telecom Open Source System Integrator - is a neutral, vendor-independent foundation. Our objective is singular: make the open telecom stack work as one validated, production-grade system.

Our objective

The open telecom ecosystem is unusually rich. Excellent open-source projects already exist for every layer - 5G Core, RAN and O-RAN, the RIC, SMO, applications, post-quantum security, and the cloud-native substrate beneath them. What it has lacked is a neutral party that makes these pieces work together as a coherent whole. TOSSI is that party.

Mission: to integrate, validate, and steward the open telecom stack - from 5G Core and O-RAN through the RIC, SMO, applications, post-quantum security, and the cloud-native substrate - into a coherent, tested, production-grade system, under neutral and transparent governance.

We think of it as a distribution for open telecom: we don’t reinvent the network functions, we select, version, integrate, and validate them so they boot and run as one system.

What a system integrator does

We are an integrator, not an implementer. We rarely ship a new core, RAN, or controller of our own - our deliverables are the glue, the tests, and the trust.

Integrate

Reference architectures and integration blueprints that wire the layers together across the standardized interfaces (SBI, N2/N3/N4, F1/E1, E2, A1, O1/O2).

Validate

Conformance and interoperability test suites against 3GPP and O-RAN ALLIANCE specifications - published vendor-agnostically as facts, not endorsements.

Secure

Post-quantum, crypto-agile hardening woven through every interface, aligned to the NIST FIPS 203 / 204 / 205 standards.

Steward

Neutral, transparent governance so no single vendor can capture the stack, and so the work stays open to everyone who depends on it.

What our emblem means

Swan - discernment in architecture & standards
Network wing - O-RAN, post-quantum security & open-source systems
Waves & signal arcs - telecom
Lotus - knowledge & purity of intent

What TOSSI is - and is not

TOSSI’s neutrality is the product. To stay trustworthy, we are deliberate about what we do and don’t do.

What TOSSI is

A neutral, vendor-independent integrator
Upstream-first - fixes land in the source projects
A producer of reference architectures, blueprints, and conformance
Secure and post-quantum by default

What TOSSI is not

A vendor or a product company
A hard fork of the projects it integrates
A single project - it is the integration of many
A standards body - standards belong to 3GPP, the O-RAN ALLIANCE, the IETF, and ETSI

Explore

Reference Architecture The end-to-end blueprint: how the pillars compose and the interfaces between them.

Documentation The full open telecom stack, pillar by pillar.