Recently, AT&T introduced something it’s calling the Open Architecture for a Disaggregated Network Operating System (dNOS). And the service provider wrote a white paper about it. But it left many stakeholders in open source networking kind of scratching their heads. SDxCentral spoke with Chris Rice, senior vice president of AT&T Labs, Domain 2.0 Architecture, to get a better understanding.

The dNOS white paper focuses heavily on routers, so that got a lot of people thinking it was an initiative related to AT&T’s recent acquisition of Brocade’s Vyatta router assets.

Rice laughed at that misunderstanding. “In no way is the white paper itself about a Vyatta product,” he said. “Vyatta is a part of AT&T now, but we have a lot of people in Labs who are routing experts. Vyatta certainly added to that talent depth we had.”

The dNOS white paper is the culmination of internal work within AT&T as part of the move toward white box hardware that it’s been looking at for some time.

Rice also said dNOS is not focused more on routers than switches. “Switches are Layer 2 and much simpler; routers are Layer 3 and support a lot more protocols,” he said. “DNOS can apply to both. But frankly, it’s going to be much simpler to do in switches. We talked about routers in the white paper because we think it’s much harder.”

To put a point on it, dNOS is not specifically about switching or routing, “dNOS is our network operating system for white box,” Rice said.

The term “white box” gets thrown around all over the place. But what does it mean for dNOS?

Rice said, “It’s really something that doesn’t use standard CPU for the data plane. It’s using some kind of network processor for the data plane. You need a separate operating system for that. With dNOS we want to build one that’s consistent and make it flexible. The Open Compute Project allows you to put designs in for the hardware, but not for corresponding software.”

He said a CPU from companies such as Intel or AMD are generalized processors meant to do many tasks pretty well. Whereas a network processor from companies such as Barefoot, Broadcom, or Cavium does a few things really well. “Network processors route packets at a very high rate; that’s the routing data plane I’m talking about,” said Rice. “As opposed to things you can do at a CPU in the cloud.”

For its network cloud, AT&T is using the Open Networking Automation Platform (ONAP) for the operating system. “But we do need a networking operating system that is consistent for the ops team on these white boxes we’ll be deploying,” he said.

AT&T identifies four main stakeholder groups for dNOS:

• People who are already building network operating systems;
• Merchant silicon companies;
• Companies that build network protocols - like an OEM for software stacks;
• Service providers.

The dNOS white paper gave a call to action to stakeholders. Asked how AT&T is reaching out to rally support, Rice said, “When you write a white paper, people contact you. We’ve had more interest than I would have thought given the effort we’ve put into that part of it so far. Something like this doesn’t take off unless you get a good amount of scale in those four areas.”

Rice also said the public outreach for dNOS would follow “a similar playbook as ONAP.” And now that ONAP has taken off, the participants in that group will probably help evangelize dNOS, as well.