The Open Networking Foundation (ONF) today open sourced the Stratum project and said it will be the foundation for ONF’s next-generation SDN stack for operators.

Stratum is a silicon-independent switch operating system for software-defined networks that runs on a variety of switching silicon and various whitebox switch platforms. It’s now available under the Apache 2.0 open source license.

ONF has big plans for the open source project, and these plans promise to be a hot topic at this week’s ONF Connect event in Santa Clara, California.

“Ultimately, Stratum will become the substrate, the switching layer upon which all of ONF’s platform runs,” said Timon Sloane, ONF vice president of marketing and ecosystem. “We announced it last year — an open source initiative to build a next-gen, SDN thin switch to run on hardware switches. And we’ve made significant progress. What’s taken the longest is ensuring that Stratum can support multiple ASIC hardware options on a whole spectrum of white box platforms.”

This includes Barefoot’s Tofino and Tofino 2 Ethernet switch ASICs, said Ed Doe, vice president in Intel’s Connectivity Group and general manager of Barefoot, in a statement. Intel bought Barefoot in June.

“We are excited to see Stratum reach the important milestone of open sourcing the project’s code as this will fuel the next level of innovation in the networking industry,” Doe said.

Google released the seed code in March 2018, and it now has a number of white box vendors, chipmakers, and operators working on the project. In addition to Intel/Barefoot, these include NTT Communications, Broadcom, Edgecore Networks, Delta Networks, Inventec, Stordis, and PLVision.

“In collaboration with the ONF, we are realizing our vision to expand Stratum’s industry reach and adoption,” said Amin Vahdat, engineering fellow, VP and technical lead for networking at Google, in a statement. “By making it possible to establish a ‘contract’ with the networking device, Stratum allows enterprises to unambiguously define system behavior and take advantage of the latest switching technologies without reworking the underlying control software.”

Because it runs on a variety of hardware platforms, Stratum helps operators avoid vendor lock due to proprietary silicon interfaces and closed software APIs. Stratum takes the opposite approach and allows vendors to integrate new network devices. The P4- (open source programming language) based interface between the Stratum switch and its controller means that the switch can be swapped with those from a variety of vendors without the need for controller modification or network retest and validation.

It also exposes a set of SDN interfaces including P4, P4Runtime, OpenConfig, and gNMI, which allow for “never-before seen in SDN or open networking” capabilities, Sloane said. This includes programmability of forwarding behaviors, zero-touch operations, and full automated life-cycle management — all at cloud-developer speed.

“Stratum is the first case where there’s an open source switch OS that really supports the whole spectrum of operations of a switch, all the way from powering it up to LEDs to running traffic,” he added. "OpenFlow switches and the original SDN really only enabled the control of traffic flows. Stratum is the forward-leaning work at ONF. It’s the foundation that all of our other platforms like Trellis and Seba will run on — we have a vision of that.”