Open Networking Foundation

The ONF was launched in March 2011 by Deutsche Telekom, Facebook, Google, Microsoft, Verizon, and Yahoo! to accelerate the adoption of SDN. Its founding mission was to standardize OpenFlow, a protocol that separates the control plane from the data plane in network switches, enabling centralized, programmable network control.¹ The consortium aimed to move networking away from proprietary, vertically integrated hardware toward open, software-driven architectures, fostering innovation and reducing costs.

The ONF has overseen several influential projects. OpenFlow, its first major output, defined a standard interface for controlling forwarding tables in switches, and was later extended to support a wide range of network devices. The ONOS (Open Network Operating System) project, contributed by AT&T and others, provides a scalable SDN controller for service providers. CORD (Central Office Re-architected as a Datacenter) reimagines central offices using cloud principles, and has been deployed in proof-of-concept trials by AT&T and others.² The ONF also collaborates with the Linux Foundation on projects like P4 and Stratum, which enable protocol-independent data planes.

The ONF has significantly influenced the networking industry by promoting open standards and fostering a vibrant ecosystem of vendors, operators, and researchers. Its work has contributed to the widespread adoption of SDN in data centers, WANs, and access networks. In 2017, the ONF merged with the OpenDaylight Project, consolidating SDN efforts under one umbrella. More recently, the ONF has focused on next-generation topics such as edge computing, 5G, and artificial intelligence-driven networking, while continuing to support its existing projects.

Beyond its headline projects, the ONF has supported niche initiatives like the OpenFlow Driver for the Mininet network emulator, which enables rapid prototyping of SDN applications. It also published the "SDN Architecture" documents that define the layered model of SDN, which have been cited in numerous academic papers. The ONF's "Northbound Interfaces" working group explored APIs for application-to-controller communication, though it was later disbanded. Additionally, the ONF has hosted plugfests where vendors test interoperability of their SDN products, a practice that has been crucial for ensuring multi-vendor compatibility.

SDN

Software-defined networking, an architecture that decouples network control from forwarding.

OpenFlow

A communications protocol that gives access to the forwarding plane of a network switch.

ONOS

Open Network Operating System, an SDN controller for service providers.

CORD

Central Office Re-architected as a Datacenter, a project to transform central offices using cloud principles.