Cumulus Networks and Dell still believe they've got a revolution brewing, no matter what Cisco might say.

In 2010, as software-defined networking (SDN) was just leaving the nest, JR Rivers and cohorts founded Cumulus to serve a like-minded cause: open networking, where customers would buy generic hardware and load it with the operating systems of their choice.

Cumulus is one of the companies aiming to provide that software, a full Linux OS that includes networking features. It's enlisted partners including Dell, Hewlett Packard Enterprise (HPE), and Mellanox — although Dell, with its OS10, now has open networking software of its own.

At the recent OpenStack Summit in Austin, Texas, I caught up with Rivers, who became Cumulus's CTO after ceding the CEO position to Josh Leslie. We talked about the Dell partnership and Cumulus's place in the world, now that the battle lines in white-box switching and SDN are more clearly drawn.

The partnership with Dell was exciting at first, but now it's offering other software options, including its own OS10. What's that meant to Cumulus?

Rivers: Everybody thinks we should have that special relationship where Dell is pimping only us, but that's actually bad for us. You want open networking, because in the grand scheme of things, it's a better sale for Dell to make. It gives them opportunity; it gives everybody opportunity. If they start picking a favorite, and only pushing that favorite, they might as well just keep selling FTOS [the Force10 operating system, long-ago acquired by Dell] to everybody.

We do a lot of business through Dell — in terms of dollars generated, we're the largest by far. Lots of really big deals, high-profile stuff. It's appropriate for them to offer a lot of options. In this industry that we envisioned, it's super important for there to be competitors at all levels.

The "we envisioned" — you mean open networking, right? How would you explain the vision there?

Rivers: Picture in your mind an Ethernet switch plugged into a cable, and the cable's all tied down in a rack. Once you've installed Vendor X as that appliance, what's the probability you ever swap it out? Pretty much zero, right?

In the old days, you also picked an operational model when you bolted that thing in. You didn't do that for anything else in your IT system, especially on the server side, but you picked that operating model, and as a company, it's truly hard to go away from it.

So as people are, like, "Hey, we're getting serious about things like OpenStack" — they've messed around with it in a PoC, and this thing works now — they want hardware that they can get the right software for. They don't want operational lock-in on the software side. You end up with a good ecosystem from the customer's standpoint, which is really what drives the change that we're all looking for.

Because in the end, when you roll it all back — us, Dell, Mellanox, HPE, Big Switch — in the end, Cisco's got a huge pie that we can all just carve up. In the end, that's what everybody needs to be fighting for, not who's No. 6 versus who's No. 7. Obviously, Cisco's never going to go away. But that's the goal.

Does that really match what Dell wants?

Rivers: That was Tom Burns's vision going in and I think Michael Dell's as well, and they're super adamant about it. From a relationship perspective, there's all kinds of stuff you guys don't see from these talks. They show us the roadmap way in advance. I have quarterly drinks with their VP of engineering, talking about roadmaps and issues. A lot of the other companies aren't doing that. They don't have that tight a relationship.

What Dell has recognized is: We help them a lot. We port our software really fast. We can support a broad number of their platforms. So, we find issues for them. So, before they ship a box, we find out this BIOS is wrong, or this is busted. We help them do QA. They do a great job by themselves, but it's just another set of eyes looking at it from a different view.

Even so, it sounds as if we shouldn't expect Dell to stop doing its own networking OS.

Rivers: We anticipate for at least an amount of time, that companies like Dell will continue doing their own OSs, because they want to wait and see where the market goes. Our hardware partners kind of go through this long dating-to-marriage kind of thing — right now, Dell's a reseller, but we're working on an OEM relationship with them. Everybody that we're with is moving closer and closer to an OEM model with us.

I can guarantee you that if Cisco woke up tomorrow morning and said, "You know what? We're going to do NX-OS in the Cumulus model, and we're not going to sell it direct. We're only going to sell it through OEM," Dell would quit working on FTOS. Because if that happened, a lot of customers would take the Cisco OS on Dell hardware. But Cisco would never do that!

In the context of Dell, then, how does OS10 compare to Cumulus Linux?

Rivers: OS10 Base has no networking function. They deliver that to Microsoft, because Microsoft said, "Hey, we want to buy your switching hardware to run SoNIC [Software for Open Networking in the Cloud] on." It's just the base Linux that makes the fans spin and the power supplies work and LEDs blink.

Later on this year, they're going to have the real OS10, which actually has networking functionality in it. We haven't seen that part yet, but given my intuition into the company, it's going to be pretty much a port of the existing FTOS into that space. So when you go use that thing, it's going to look like FTOS.

It would be familiar to the installed base, without being ancient.

Rivers: Yes. They're modernizing their Force10 asset.

OK, so let's talk about Microsoft SoNIC. That's an operating system too. Doesn't that tread on your turf?

Rivers: They took a lot of stuff from us [open source stuff, that is]. They brought our stuff in; they tested it out. But the Microsoft operations team had already kind of tooled up around the Cisco CLI. So, they looked at our technology and said, "Yeah, it looks great, but the thing is: We have existing operations tools, and we want to do our own thing."

So, from our perspective, Microsoft was never going to be a customer. They were either going to be a Cisco customer, or do their own thing. It's good to finally see them going off and doing their own thing.

The interesting thing, though, about SoNIC is: It cost Microsoft way more to develop and support SoNIC than it would have cost to use our software. I've talked to some of the guys that were working on it, as they were going through it. We had given them a quote, and they said, "Wow, that's way less [than what we spent]." And I turned that quote into FTEs [field technical engineers] for them. I said, "This quote is that many people." And they go, "Wow, that's a lot smaller than the team we have."

People look at the network switch and say, "I can do that." It's a problem they think they can solve. And they're right. These are smart people. What they really don't think about is: How much is it going to cost me to solve it, and what am I not doing while I'm solving that problem? So, we're starting to see some others circling back around, people who have done their own thing. It just doesn't make sense for them.