GNPy v3.0 Released: A Major Step Forward for Optical Network Planning
The latest release of Telecom Infra Project's GNPy (v3.0) delivers one of the most significant updates in recent years. While primarily aimed at optical network engineers and planners, the release also improves the foundation for anyone building automated transport network design and optimization workflows.
What is GNPy?
GNPy is an open-source optical route planning and DWDM network optimization library widely used for modeling and engineering optical transport networks. It applies Gaussian Noise models to predict transmission performance and supports network planning, service feasibility analysis, and path computation.
Highlights from Version 3.0
Improved Accuracy of Receiver Modeling
One of the most impactful enhancements is the introduction of improved transceiver feasibility evaluation. The software now takes receiver power constraints into account, includes more detailed receiver modeling, and adds Q-margin calculations. These additions help planners better assess whether a proposed optical path will operate reliably in production environments.
For operators, this means simulation results are becoming increasingly aligned with real-world deployment considerations.
Improved Fiber and Spectrum Modeling
Version 3.0 introduces enhancements in fiber modeling and spectrum handling. Channel numbering and spectrum propagation have been aligned, eliminating historical inconsistencies between the design and propagation phases. Channels now begin at channel 0, and both lower and upper spectrum boundaries are handled consistently.
While this is technically a breaking change, it improves predictability and removes subtle edge cases that could previously affect channel assignments and spectrum-related calculations.
Better Standards Alignment
Another notable development is the continued move toward more consistent YANG-compatible output formats. As transport networks increasingly integrate with SDN controllers, orchestrators, and model-driven management frameworks, standards alignment becomes essential. GNPy's enhanced output consistency should simplify integration into modern automated network management environments.
Modernized Software Stack
The project has completed a substantial dependency refresh, moving to current versions of major Python libraries including NumPy, Pandas, NetworkX, Matplotlib, SciPy, and others. Support for Python releases older than 3.11 has been dropped, and execution now requires NumPy 2.x.
This modernization improves maintainability and positions the project for future feature development, although users upgrading existing environments should plan for compatibility testing.
What This Means for the Industry
The v3.0 release reflects a broader trend in optical networking: planning tools are evolving from offline engineering utilities into components of automated operational workflows. More accurate impairment modeling, closer alignment with data models such as YANG, and improved software foundations all support the industry's move toward intent-based and model-driven network operations.
For network operators, equipment vendors, and researchers, GNPy continues to strengthen its position as a reference platform for open optical network planning and performance estimation.
Bottom Line
GNPy v3.0 is more than a routine update. With enhanced receiver awareness, refined spectrum modeling, stronger standards alignment, and a modernized software base, the release improves both the accuracy and operational relevance of optical network planning workflows. Organizations already using GNPy should review the breaking changes, but the benefits make this upgrade well worth evaluating.
Get involved with TIP OOPT
GNPy is developed through the Telecom Infra Project’s Open Optical & Packet Transport (OOPT) Project Group, bringing together operators, technology suppliers, researchers, and other industry contributors to advance open, interoperable approaches to transport networks.
The work doesn’t stop with this release. Connect with the TIP OOPT community at ECOC 2026 in Málaga, where contributors will continue engaging the optical networking ecosystem around open technologies, interoperability, automation, and the evolution of transport infrastructure.
Then, continue the conversation at FYUZ 2026, November 3–5 in Seattle, where the TIP community and broader telecom ecosystem will explore how these technologies are progressing into real-world deployments and increasingly automated network operations.
Help shape what comes next. Get involved with the TIP OOPT Project Group, connect with the community at ECOC 2026, and register for FYUZ 2026 at FYUZ.org.
