|By Michael Bushong||
|January 7, 2014 10:00 AM EST||
Why is it that the definition of SDN continues to get debated?
I think the definition of SDN remains a bit squishy. And while I am not entirely certain that it matters (people shouldn’t be buying SDN; they should be building networks), it is an interesting phenomenon, and understanding it better could help with the education process.
When most people talk about what SDN is, they tend to fall into two camps: principles and protocols. You will frequently hear SDN described as the separation of control and forwarding planes. You probably hear people talking about SDN needing to be “open” (a horribly imprecise term as I have argued before). These are the people who fall on the principles side. They point less to specific instantiations of technologies and more to the guidelines that define SDN.
The other camp will point to specific protocols and technologies. They rally around the OpenFlow banner for sure, but they might include other technologies like BGP-TE, PCE, ALTO, and I2RS. They see SDN as an architecture with specific building blocks, and the presence of those building blocks determines the SDN-ness of a solution.
I actually don’t think that either of these positions is correct.
I was debating last week whether GMPLS was SDN. It certainly focuses on the separation of control and forwarding plane. It is an open standard. It is absolutely implemented in software. It seems to hit most of the framework criteria for inclusion in the SDN camp. The conclusion of whether GMPLS is SDN or not is less interesting than the discussion that surrounded it.
Does software define software-defined? Claiming something is software-defined because it is implemented in software is probably among the lamest definitional requirements around. The reality is that the vast majority of traditional networking features are all implemented in software. In fact, the major vendors spend north of 80% of their R&D on software-related efforts. By this definition, everything is software-defined.
The real distinction people seem to be trying to make when they talk about software implementations is whether the functionality is resident on a networking device, or whether it sits somewhere on top of the network (as with a controller). But we should be clear about this. Whether some application runs on or off the box is a packaging detail, not some core attribute. Networking devices all have some forwarding ASIC and a general processor. Whether you write something to run natively within the sheet metal or on some server somewhere is irrelevant. Put differently, if your vendor of choice decided to ship their boxes with the central processing card physically separated (it sits a half micron on top, with separate sheet metal, power, and cooling), would you suddenly brand the solution software-defined?
[Special callout to Mike Dvorkin (@dvorkinista) who frequently makes this argument on social channels.]
Is the separation of control and forwarding the meaningful determinant? Network device behavior is all state-driven. Whether that state is determined by persistent configuration or learned through some protocol is secondary. More simply, how important is it how state gets onto the device? More simply, if you set the state via an on-box CLI or via a controller, does that make the solution any more or less SDN?
When most people talk about control and forwarding, they are really having a discussion about management planes. Controller-based solutions certainly separate the management plane. But so do policy servers, OSS/BSS solutions, and even well-written Perl scripts that pull information from a content versioning system as part of device management.
My point here is not to say that separation is not important, but rather that it is likely not enough by itself to determine the SDN-ness of a particular solution.
Does Open make something SDN? No one will say that merely being open (for whatever definition of open you mean) is enough to make something SDN. The real question is whether something can be SDN and not be open. The answer here gets pretty religious, but that is largely dependent on how people have defined SDN. Can you build a software-implemented, controller-based solution that uses proprietary protocols? Absolutely. If that solution is deployed for 8 years and then the IETF ratifies a standard for the base protocol, has your deployed solution gone from non-SDN to SDN despite the lack of solution changes?
So where did all of this conversation land?
It’s not that I think there are not important principles to be considered before labeling something SDN. I just think that it is less about technology and more about context. It is absolutely conceivable to me that a particular technology can exist in both SDN and non-SDN architectures. How a protocol is used determines whether it is SDN or not. The examples are virtually endless, but I would start with things like BGP, XMPP, NETCONF, YANG, and yes, even GMPLS. Similarly, I think there are controller-based solutions that are non-SDN, just as there might be non-controller-based solutions that could be SDN.
This means that the conversation needs to move away from the technological building blocks and more to the contexts that matter. I’ll offer up three here:
- Delegation – OSS/BSS systems have already addressed the management problems inherent in networks built from different devices delivered by different vendors. Cannot the solution simply be to implement master translators that push configuration down to however many devices? It seems to me that SDN is about removing the complexity of managing individual elements. That can only happen through delegation. Central controllers are great, but only if they can pass requirements to individual elements rather than having to manage them all in detail. The analogy I like here is one of the modern corporation. Imagine how effective your company would be if your CEO told every individual what to do. Delegation matters.
- Abstraction - And delegation depends on abstraction. If the goal of SDN is to make workflows more manageable and networks more better (more easily managed, more responsive to applications, more intelligent, more whatever), then we need to abstract out some of the complexity. We need to work less in device-specific directives (read: configuration knobs), and more in overarching intent. The only way that different part of the IT infrastructure can ever collaborate is through a common language, and that will require abstraction. Expecting compute, storage, or applications to speak in terms of VLANs and ACLs is no more practical than turning network admins into storage or compute junkies.
- Globality – Centralizing control is not about where software runs; it is about what that software can do. The whole premise of controller-based solutions is that having a global view of the available resources allows for more intelligent decisions to be made. If your network behaves exactly the same way with or without OpenFlow (meaning all traffic effectively uses the same paths), then does it even matter if you call it SDN or not? We need to be in the business of doing things better, not just different. And that requires globality.
These might not be the only (or even right) contexts to think about, but they at least start to frame the discussion differently. I think it is entirely possible to build open, controller-based systems that fail to deliver against any of the promises of SDN, just as it is possible to use existing technologies in new ways. Ultimately, it is the context – not the capability – that determines whether the promises of SDN are achievable.
[Today's fun fact: A car that shifts manually gets 2 miles more per gallon of gas than a car with automatic shift. Of course all that extra work requires more sustenance, so it's about a wash environmentally.]
"IoT is going to be a huge industry with a lot of value for end users, for industries, for consumers, for manufacturers. How can we use cloud to effectively manage IoT applications," stated Ian Khan, Innovation & Marketing Manager at Solgeniakhela, in this SYS-CON.tv interview at @ThingsExpo, held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA.
Dec. 4, 2016 04:15 PM EST Reads: 4,137
"We're a cybersecurity firm that specializes in engineering security solutions both at the software and hardware level. Security cannot be an after-the-fact afterthought, which is what it's become," stated Richard Blech, Chief Executive Officer at Secure Channels, in this SYS-CON.tv interview at @ThingsExpo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
Dec. 4, 2016 04:15 PM EST Reads: 593
Information technology is an industry that has always experienced change, and the dramatic change sweeping across the industry today could not be truthfully described as the first time we've seen such widespread change impacting customer investments. However, the rate of the change, and the potential outcomes from today's digital transformation has the distinct potential to separate the industry into two camps: Organizations that see the change coming, embrace it, and successful leverage it; and...
Dec. 4, 2016 03:00 PM EST Reads: 3,245
Data is the fuel that drives the machine learning algorithmic engines and ultimately provides the business value. In his session at Cloud Expo, Ed Featherston, a director and senior enterprise architect at Collaborative Consulting, discussed the key considerations around quality, volume, timeliness, and pedigree that must be dealt with in order to properly fuel that engine.
Dec. 4, 2016 02:15 PM EST Reads: 1,991
We are always online. We access our data, our finances, work, and various services on the Internet. But we live in a congested world of information in which the roads were built two decades ago. The quest for better, faster Internet routing has been around for a decade, but nobody solved this problem. We’ve seen band-aid approaches like CDNs that attack a niche's slice of static content part of the Internet, but that’s it. It does not address the dynamic services-based Internet of today. It does...
Dec. 4, 2016 02:00 PM EST Reads: 915
Internet of @ThingsExpo, taking place June 6-8, 2017 at the Javits Center in New York City, New York, is co-located with the 20th International Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. @ThingsExpo New York Call for Papers is now open.
Dec. 4, 2016 02:00 PM EST Reads: 1,898
What happens when the different parts of a vehicle become smarter than the vehicle itself? As we move toward the era of smart everything, hundreds of entities in a vehicle that communicate with each other, the vehicle and external systems create a need for identity orchestration so that all entities work as a conglomerate. Much like an orchestra without a conductor, without the ability to secure, control, and connect the link between a vehicle’s head unit, devices, and systems and to manage the ...
Dec. 4, 2016 02:00 PM EST Reads: 572
20th Cloud Expo, taking place June 6-8, 2017, at the Javits Center in New York City, NY, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy.
Dec. 4, 2016 01:45 PM EST Reads: 2,155
Everyone knows that truly innovative companies learn as they go along, pushing boundaries in response to market changes and demands. What's more of a mystery is how to balance innovation on a fresh platform built from scratch with the legacy tech stack, product suite and customers that continue to serve as the business' foundation. In his General Session at 19th Cloud Expo, Michael Chambliss, Head of Engineering at ReadyTalk, discussed why and how ReadyTalk diverted from healthy revenue and mor...
Dec. 4, 2016 01:30 PM EST Reads: 1,535
The 20th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held June 6-8, 2017, at the Javits Center in New York City, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Containers, Microservices and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportunity. Submit your speaking proposal ...
Dec. 4, 2016 12:45 PM EST Reads: 2,124
You have great SaaS business app ideas. You want to turn your idea quickly into a functional and engaging proof of concept. You need to be able to modify it to meet customers' needs, and you need to deliver a complete and secure SaaS application. How could you achieve all the above and yet avoid unforeseen IT requirements that add unnecessary cost and complexity? You also want your app to be responsive in any device at any time. In his session at 19th Cloud Expo, Mark Allen, General Manager of...
Dec. 4, 2016 12:30 PM EST Reads: 1,671
The Internet of Things (IoT) promises to simplify and streamline our lives by automating routine tasks that distract us from our goals. This promise is based on the ubiquitous deployment of smart, connected devices that link everything from industrial control systems to automobiles to refrigerators. Unfortunately, comparatively few of the devices currently deployed have been developed with an eye toward security, and as the DDoS attacks of late October 2016 have demonstrated, this oversight can ...
Dec. 4, 2016 12:00 PM EST Reads: 781
"ReadyTalk is an audio and web video conferencing provider. We've really come to embrace WebRTC as the platform for our future of technology," explained Dan Cunningham, CTO of ReadyTalk, in this SYS-CON.tv interview at WebRTC Summit at 19th Cloud Expo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
Dec. 4, 2016 11:45 AM EST Reads: 381
Bert Loomis was a visionary. This general session will highlight how Bert Loomis and people like him inspire us to build great things with small inventions. In their general session at 19th Cloud Expo, Harold Hannon, Architect at IBM Bluemix, and Michael O'Neill, Strategic Business Development at Nvidia, discussed the accelerating pace of AI development and how IBM Cloud and NVIDIA are partnering to bring AI capabilities to "every day," on-demand. They also reviewed two "free infrastructure" pr...
Dec. 4, 2016 11:15 AM EST Reads: 906
Major trends and emerging technologies – from virtual reality and IoT, to Big Data and algorithms – are helping organizations innovate in the digital era. However, to create real business value, IT must think beyond the ‘what’ of digital transformation to the ‘how’ to harness emerging trends, innovation and disruption. Architecture is the key that underpins and ties all these efforts together. In the digital age, it’s important to invest in architecture, extend the enterprise footprint to the cl...
Dec. 4, 2016 11:15 AM EST Reads: 2,211
"Dice has been around for the last 20 years. We have been helping tech professionals find new jobs and career opportunities," explained Manish Dixit, VP of Product and Engineering at Dice, in this SYS-CON.tv interview at 19th Cloud Expo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
Dec. 4, 2016 10:45 AM EST Reads: 884
More and more brands have jumped on the IoT bandwagon. We have an excess of wearables – activity trackers, smartwatches, smart glasses and sneakers, and more that track seemingly endless datapoints. However, most consumers have no idea what “IoT” means. Creating more wearables that track data shouldn't be the aim of brands; delivering meaningful, tangible relevance to their users should be. We're in a period in which the IoT pendulum is still swinging. Initially, it swung toward "smart for smar...
Dec. 4, 2016 09:45 AM EST Reads: 558
Successful digital transformation requires new organizational competencies and capabilities. Research tells us that the biggest impediment to successful transformation is human; consequently, the biggest enabler is a properly skilled and empowered workforce. In the digital age, new individual and collective competencies are required. In his session at 19th Cloud Expo, Bob Newhouse, CEO and founder of Agilitiv, drew together recent research and lessons learned from emerging and established compa...
Dec. 4, 2016 09:30 AM EST Reads: 812
Extracting business value from Internet of Things (IoT) data doesn’t happen overnight. There are several requirements that must be satisfied, including IoT device enablement, data analysis, real-time detection of complex events and automated orchestration of actions. Unfortunately, too many companies fall short in achieving their business goals by implementing incomplete solutions or not focusing on tangible use cases. In his general session at @ThingsExpo, Dave McCarthy, Director of Products...
Dec. 4, 2016 09:30 AM EST Reads: 616
Businesses and business units of all sizes can benefit from cloud computing, but many don't want the cost, performance and security concerns of public cloud nor the complexity of building their own private clouds. Today, some cloud vendors are using artificial intelligence (AI) to simplify cloud deployment and management. In his session at 20th Cloud Expo, Ajay Gulati, Co-founder and CEO of ZeroStack, will discuss how AI can simplify cloud operations. He will cover the following topics: why clou...
Dec. 4, 2016 08:00 AM EST Reads: 724