Introducing NetMaestro: Open Source Network Modeling and Simulation
Network engineers need to evaluate changes to infrastructure without disrupting the systems that depend on it. Testing a new configuration, replacing equipment, or investigating a potential failure can be difficult when physical testbeds are expensive and production networks cannot be used for experimentation.
Kitware is developing NetMaestro, an open source network modeling and simulation tool that allows engineers to investigate congestion, compare configurations, and explore what-if scenarios using virtual network models before making changes to production infrastructure.
Developed through a U.S. Department of Energy (DOE) Phase II Small Business Innovation Research (SBIR) project, NetMaestro builds on established parallel discrete-event simulation technologies to support network planning and analysis.
The Challenges of Network Testing and Simulation
Consider a facility that needs to determine where congestion might occur across a thousand-node network. Building a physical testbed at that scale may be impractical. Similarly, testing how traffic reroutes after a link failure could require changes that risk disrupting an operational network.
Simulation provides a way to investigate these questions using a model of the network. However, high-fidelity simulation presents its own challenges. Simulating just a millisecond of network traffic at packet-level detail can take hours. Configuring parallel discrete-event simulations can also require specialized expertise.
NetMaestro pairs scalable simulation engines with a web-based application, so engineers can set up and run what-if studies without writing simulation code. To help address these computational demands, Kitware is collaborating with Argonne National Laboratory (ANL) and Rensselaer Polytechnic Institute (RPI) to develop machine learning surrogates that accelerate simulations when full packet-level detail is not required.
The Technology Behind NetMaestro
NetMaestro is built on ROSS and CODES, parallel discrete-event simulation engines used to model large-scale HPC systems and networks. These engines provide the simulation foundation, while the open source Resonant stack provides the web application used to work with NetMaestro.
The NetMaestro application runs on Windows, macOS, and Linux. Simulations can be executed locally on macOS or Linux. Engineers can therefore access the application from their desktops while running simulations on separate computing resources when needed.
Exploring Network Changes Through Simulation
Comparing Network Designs
Before investing in new equipment or changing a network architecture, engineers need to understand how different configurations might perform. NetMaestro supports what-if analysis of existing and proposed networks, allowing teams to explore design alternatives before committing resources to physical deployment.
Investigating Congestion and Capacity Constraints
Changes in traffic patterns or volume can create congestion, oversubscription, and performance constraints. NetMaestro can model these conditions, including traffic hotspots that would be difficult or costly to reproduce on physical hardware, to show where capacity constraints are likely to emerge.
Understanding Failure Scenarios
When a network link or device fails, traffic shifts to alternative routes and can create bottlenecks elsewhere. NetMaestro allows engineers to investigate failure and failover scenarios to understand how traffic might reroute and where new bottlenecks could emerge.
Evaluating New Equipment and Architectures
New networking equipment and architectures can be difficult to evaluate before physical testing is practical. NetMaestro provides a modeling foundation for investigating proposed devices and architectures under different network conditions.
Free Webinar
To see these capabilities in action, join Kitware’s Caitlin Ross for the November 4 webinar, “Network Digital Twins with NetMaestro for Wide-Area Network Simulation.” From 12–1 PM ET, Caitlin will demonstrate how NetMaestro can be used to evaluate network capacity, congestion, and configuration changes through a realistic wide-area network scenario. The session will also cover what its models capture and how they are being validated against real network testbeds.
Open Source Network Modeling
NetMaestro is open source under the Apache 2.0 license, with no software licensing fees. Organizations retain ownership of their models and data and can adapt the software to their specific network modeling requirements.
Path to a Full Network Digital Twin
Today, NetMaestro is a network modeling and what-if simulation tool. A digital twin goes further: it stays synchronized with the real network through live telemetry and can feed results back into operations. NetMaestro’s roadmap builds towards that goal:
- Validation against real networks: Simulation results are being compared against physical experiments on national research testbeds.
- Support for additional simulation engines: Support for the Structural Simulation Toolkit (SST) and ns-3 is planned.
- Telemetry integration: Incorporating network telemetry so models stay synchronized with actual operating conditions.
- Closing the loop: Longer term, we want NetMaestro to go beyond answering what-if questions to acting on the answers: testing candidate changes against a live model of the network, recommending mitigations that relieve congestion or route around failures, and with operator approval, applying those changes to the network.
Customizing NetMaestro for Your Network
Network models often need to account for specific equipment, traffic patterns, and operational requirements. Kitware works directly with teams to customize NetMaestro and integrate simulation into their existing workflows.
Our team provides:
- Collaborative R&D and development: Develop custom simulation capabilities and component models for specialized hardware, protocols, and network architectures.
- Integration and deployment: Connect NetMaestro to existing network data and engineering workflows, with simulation execution supported on workstations or HPC resources.
- Technical support and training: Provide ongoing customization, maintenance, and hands-on training to help teams use NetMaestro within their environments.
Continuing the Conversation at Internet2 Tech Exchange 2026:
At Internet2 Tech Exchange 2026, Kitware’s Caitlin Ross will present “NetMaestro: Network What-If Analysis” on Wednesday, October 28, from 5–6 PM. The poster will focus on the challenges research and education network operators face when making changes to production infrastructure without the ability to test potential outcomes beforehand.
NetMaestro addresses this challenge by making high-fidelity network simulation accessible through an open source, browser-based application. Working with collaborators at Rensselaer Polytechnic Institute and Argonne National Laboratory, Kitware is developing faster simulation methods, including machine learning surrogates, while preserving the switch-level detail needed to analyze network behavior.
The poster will outline NetMaestro’s development roadmap and provide an opportunity for network operators to share how they currently plan infrastructure changes, what challenges they encounter, and what capabilities would make simulation practical within their workflows.
Attending Internet2 Tech Exchange 2026? Visit the poster session to share your perspective on network planning and simulation. To learn more about NetMaestro or discuss your organization’s network modeling needs, contact Kitware.