One of the many takeaways I got from Future:Net last week was the desire for networks to do more. The presenters were talking about their hypothesized networks being able to make intelligent decisions based on intent and other factors. I say “hypothesized” because almost everyone admitted that we aren’t quite there. Yet. But the more I thought about it, the more I realized that perhaps the timeline for these mythical networks is a bit skewed in favor of refresh cycles that are shorter than we expect.

Software Eats The World

SDN has changed the way we look at things. Yes, it’s a lot of hype. Yes, it’s an overloaded term. But it’s also the promise of getting devices to do much more than we had ever dreamed. It’s about automation and programmability and, now, deriving intent from plain language. It’s everything we could ever want a simple box of ASICs to do for us and more.

But why are we asking so much? Why do we now believe that the network is capable of so much more than it was just five years ago? Is it because we’ve developed a revolutionary new method for making chips that are ten times smarter and a hundred times faster? No. In fact, the opposite is true. Chips are a little faster and a little cheaper, but they aren’t custom construction. Most companies are embracing merchant silicon from companies like Broadcom and Mellanox. So, where’s all this functionality coming from?

Its’ the “S” in SDN. We’re seeing software driving this development. Yes, it’s the same thing we’ve been saying for years now. But it’s something more now. Admins and engineers aren’t just excited that network devices are more software now. They’re expecting it. They’re looking to the software to drive the development. Gone are the days of CLI-only access. Now, the interfaces are practically built on API-driven capabilities. The Aruba 8400 seems like it was built for the API first, with the GUI being a superset of API functions. People getting into the networking world are focusing on things like Python first and CLI syntax second. Software is winning again.

It’s like the iPhone revolution. The hardware is completely divorced from the software. I can upgrade to the latest version of Apple’s iOS and get most of the functionality I want in the OS. Aside from some hardware specific things the majority of the functions work no matter what. Every year, I get new toys to play with. Every 12 months I can enable new functions and have new avenues available to me. If you think back to the first iterations of the iPhone ten years ago, you can see how far software development has driven this device.

Hardware For The Long Haul

However, for all the grandeur and amazement that iPhone (and Android for that matter) show, it’s also created a side effect that is causing even more problems in the mobile device world that is bleeding over into other electronics. That is the rapid replacement cycle. I mentioned above how awesome it is that you can get new functions every year in your mobile device. But I didn’t mention how people are already looking forward to the newest hardware even though they may have purchased a new phone just 10 months ago.

The desire to get faster by leaps and bounds every year is almost comical at this point. When the new device is delivered an it’s just a bit faster than the last, people are disappointed. Even I was guilty of this when I moved from a 2013 MacBook to a 2016 model. It was only 20% faster. Even with everything else I got in the new package, I found myself chasing performance over every other feature.

The desire to get better performance isn’t just limited to phones and tablets and laptops. When network designers look to increase network performance, they want to do so in a way that makes their users happy. Gone are the days when a simple gigabit network connection would keep someone pleased. We now have to develop gigabit wireless connections to the backbone network, where data is passed to servers connected by 25Gig connections to spines and super spines running at 100Gig (for now). In some cases, that data doesn’t even move any more, and instead short-lived containers are spun up next to it to make things run faster.

Networks aren’t designed like iPhones. They aren’t built to be ripped out every year and replaced with something a little faster and a little shinier. They’re designed more like cars in that regard. They are large purchases that should last for years upon years, with their performance profile dictated by the design at the time. We’ve gone through the phases of running 10Mbit hubs. We upgraded to FastEthernet. We’re now living in a cycle where Gigabit and 10/40 Gigabit switches are ruling the roost. Some of the more forward-thinking folks are adopting 25/50Gigabit and even looking to faster technologies like 400Gig connections for spines.

However, the longevity of hardware remains. Capital expenditure isn’t the easiest thing in the world to accomplish. You need to budget for new devices in the networking world. You need to justify cost savings or new applications. You can’t just buy a fast new switch or two every year and claim that it makes everything better without some kind of justification. Even if you move to the cloud with your strategy, you’re not changing the purchasing model. You’re just trading capital expenditure to operational expenditure. You’re leasing a car instead of buying it. Because if you leave the cloud, you’re back to your old switching model with nothing to show for it.

Tom’s Take

I was pretty hard on the Future:Net presenters because I felt that their talk of ditching money grubbing vendors for the purity of whitebox switching running open source software was a bit heavy handed. Most organizations are in the middle of a refresh cycle and can’t afford to rip everything out and replace it today. Moreover, the value in whitebox switching isn’t realized when you install new hardware. It’s realized when you turn your switch into an iPhone. Where software development rules the day and your hardware fades away in the background. We’re not there yet. We’re still buying hardware for the sake of hardware as the software is catching up. Networking equipment is still built and bought like a car and will be for a few years to come. Maybe we can revisit this topic in 3 years and see how far software will have driven us by then.