What Is the Open Networking Foundation?

The Open Networking Foundation (ONF) is an operator-led nonprofit consortium established in 2011 to advance software-defined networking (SDN) and network function virtualization (NFV) through the development of open source software and open standards. The founding members included AT&T, Deutsche Telekom, Facebook, Google, Microsoft, and Verizon, operators who sought to reduce their dependence on proprietary network equipment by decoupling the control plane from the data plane in network devices. ONF became the recognized institutional home for SDN advocacy, specifications, and open source projects throughout the 2010s.

SDN, the architectural principle that ONF was organized to promote, separates the decision-making logic of a network (the control plane) from the forwarding hardware (the data plane), allowing network operators to programmatically configure and manage network behavior from a centralized software controller. The ONF contributed to the formal definition of SDN and published interface specifications that established OpenFlow, a protocol for communication between SDN controllers and forwarding elements, as an early standard for this architecture.

Software-Defined Networking Mission

The ONF's central contribution to the networking industry has been providing an organizational structure and a neutral technical forum in which competing operators and vendors could collaboratively develop open source alternatives to proprietary network stacks. The consortium's work addressed a structural tension in telecommunications: network operators deploy equipment from a small number of vendors and have limited ability to customize, extend, or replace individual software components in their networks.

By publishing open source software under permissive licenses (primarily Apache 2.0), ONF made it possible for operators to run network control software independently of hardware vendor roadmaps. This approach, common in enterprise computing, was applied to carrier-grade network infrastructure for the first time at scale through ONF's projects. The ONF also worked closely with the O-RAN Alliance and 3GPP to align open source implementations with evolving 5G architecture standards.

Key Projects

The ONF developed and maintained several widely adopted open source networking projects. ONOS (Open Network Operating System) is an SDN controller designed for carrier-grade deployment, supporting distributed active-active clustering for high availability. The ONOS project targets operators building white-box switching and routing infrastructure using merchant silicon hardware, decoupling software from specific vendor chipsets.

Aether is a private 5G and edge computing platform for enterprise environments. SD-Core provides an open source 5G mobile core implementing 3GPP's 5G standalone architecture. SD-RAN implements an O-RAN-compatible near-real-time RAN Intelligent Controller (nRT-RIC) for programmable radio access network management. These projects together addressed the full protocol stack of a 5G mobile network in open source form.

In 2024, ONF completed the transfer of its major project portfolio to the Linux Foundation, which now hosts Aether and associated projects under the Linux Foundation's ONF Project Group. This consolidation brought ONF's work under a larger open source governance framework with established processes for intellectual property management and industry participation.

Applications

The Open Networking Foundation's work has applications in a range of fields, including:

• Telecommunications carrier networks, enabling white-box switching deployments in backbone and edge infrastructure
• Enterprise private 5G, providing open source 5G core and RAN software for campus and industrial wireless deployments
• Cloud data centers, supporting programmable network fabric management through SDN controllers
• Research and testbed environments, providing carrier-grade open source components for experimental network architectures
• Military and government networks, enabling software-defined control of classified and tactical communication networks