CIO Tech Brief: Software-Defined Network

John W. Verity, Editor | 5/31/2013 | 24 comments

John W. Verity
(Editors Note: CIO Tech Briefs are short articles designed to give CIOs the 10,000 foot view of new and emerging technology. You'll learn terms, concepts, and the impact of the technology, but for a deeper look, check our archives, or ask in the comments, and we'll try to direct you to the right sources on our site.)

A Software-Defined Network (SDN) is the latest "coming soon" for the enterprise datacenter. Understand the basics to prepare for the inevitable questions and meetings in your future.

Is your enterprise ready for SDN? Just as virtualization defines complete servers in terms of 1s and 0s, and thus makes them a snap to provision, move, clone, and back up, defining network services in terms of 1s and 0 promises similar levels of agility. SDN is a big umbrella, the term meaning different things to different providers and technical approaches varying considerably. But the over-arching goal is to make networks much easier to reconfigure and to instantly and automatically adapt themselves to every change in demand.

The Controller is key
Current networks require manual intervention when changes are required. Whenever a change is needed to a network -- say, to tightly link a bunch of servers and storage systems that run a vital application -- network engineers have to reconfigure each and every switch and router involved. Each network component must be programmed individually. In a world of virtual servers and elastic computing clouds, the network's ability to adapt can become a significant bottleneck in the system.

As one former Yahoo CTO puts it, reconfiguring today's networks is like solving one of those puzzles in which you slide a set of 15 tiles around within a 16-tile grid to form a certain pattern. Every move can have bad side-effects.

SDN promises to free networks so that altering the network is as easy as point and click. Or even more agile than that: Software-defined networks can automatically allocate bandwidth to new flows of data immediately as they arrive, matching the flexibility and speed of elastic virtual server creation. The key to all this? Centralized control.

SDN calls for the implementation of a new networking component known as a controller that will, in a manner of speaking, sit above the network's physical fabric of cables and switches. From this vantage point, the controller will be able not only to "see" the network and its activities, but also command individual nodes to change their policies and behavior exactly as needed, moment by moment.

This controller's software will maintain a highly-detailed model of the network's many physical elements, the policies that govern different types of services (video gets priority over email, say, or servers A through J are never to be sent traffic-type X or Y), and all of the activities the network is handling right now.

It is this model, of course, that gives SDN its name. It will be an executable model, not just a static description, and it will enable the controller to make optimal decisions about how to provide different kinds of network service at any given moment.

In addition to making networks more agile, SDN promises to make them more secure, too. As it is, some datacenter networks are so large and complex that it's just about impossible to determine all of the possible pathways between any two servers. With a central controller in charge, however, all pathways can be identified and controlled, thus making security much tighter.

Supporting switches
More is required than just this all-knowing controller. Switches that can understand the controller's commands are also needed. Today's switches are not ready to do this; generally, the know-how and tools needed to change their behavior more than a little are proprietary. For SDN to take off, switch makers will have to open their boxes to receive and act on commands generated by SDN controllers.

In addition, SDN requires the final acceptance of a concept that has been gaining speed in the industry: The divorce of the control plane and data plane within the network switch and fabric. Flexible, elastic SDN depends on being able to dynamically change the structure of the network through manipulation of the control plane while those changes are reflected in the behavior of the data plane. It's a significant change in the way that switches are designed and deployed.

Unfortunately, this change is not going to happen overnight, so don't expect SDN to dominate the market anytime soon. But SDN holds the potential, everyone agrees, to open up the networking equipment market to competition as never before and thereby bring prices down -- a change, of course, that incumbent suppliers are not necessarily keen to see.

Market shifts
If established switch makers open their boxes to work with standardized SDN schemes, they risk losing much of the control over the market they have enjoyed for decades, along with the profits that go with that control. Seeing this possibility, the Cisco Systems, Brocades, HPs, and Juniper Networks of the world are moving quite cautiously, proposing their own versions of SDN even as they voice support for emerging SDN standards such as OpenFlow and XMPP.

Still, standardized SDN protocols may well disrupt the networking market in a major way. If early-stage, standards-oriented SDN companies such as Big Switch, Nicira Networks (acquired by VMware last year for whopping $1.2 billion), Embrane, Midokura, and Vyatta get their way, their SDN controllers will be able to harness white-box commodity switches, selling at rock-bottom prices, into powerful networks. In fact, Google, an early and avid user of SDN, already has begun building its own networking gear, much as it does with servers. And Facebook is developing its own open-source switch.

It's early days for SDN, and for now, only the largest datacenters will be taking advantage of it. But here's how the forward-thinking CIO can get ready for the SDN revolution:

  • Be proactive with your vendors. Get to know your current networking vendors's stand vis-à-vis SDN.
  • Keep in mind that there will be many flavors of SDN hitting the market, some aimed at the datacenter, some at the wide-area network. Each has its own characteristics.
  • Stay in touch with peers and industry consortia: see how they may be implementing the technology.
  • Have your organization's networking chief explore the technology, perhaps by attending a training course or seminar. Make sure they share their information with the entire staff on their return.
  • Hold onto your hat. SDN promises to be quite disruptive for suppliers and customers alike.
View Comments: Newest First | Oldest First | Threaded View
Page 1 / 3   >   >>
batye   E2 Tech Brief: Software-Defined Network   6/3/2013 7:38:02 AM
Re: Well Timed
interesting point but a lot of the times it also depends on the croud - knowing the buzzword or not... as it all started in the basic approach - how I see it...
batye   E2 Tech Brief: Software-Defined Network   6/3/2013 1:26:45 AM
Re: People still
interesting to know, Joe, thanks for sharing... but one of my friends told me law is the art:)
Zaius   E2 Tech Brief: Software-Defined Network   6/2/2013 7:17:36 PM
It seems all good except the 'standard' part. However, we should be patient with SDN to take shape and then we would find it well standardized. I personally, do not like technologies that do not have well defined standard, because every vendor throws in their 'signature moves' in their product. Anyway, we had to be considerate to new technology and it will get standardized once it matures (and some other disruptive technology do not emerge to replace it too soon).
Susan Nunziata   E2 Tech Brief: Software-Defined Network   6/2/2013 4:51:30 PM
Susan Nunziata
Re: People still
@Joe: that's an interesting switch--from computer science to theatre. And then law. You are quite well-rounded, and you certainly have the background to launch the next Big Social Network, AND write all the contracts for it to boot. 
Joe Stanganelli   E2 Tech Brief: Software-Defined Network   5/31/2013 11:50:28 PM
Re: People still
You're certainly welcome, Susan.  And yes, acting work and stage experience is great for developing confidence and overcoming shyness.

I switched from computer science to theatre.  Honestly, had I to do it over again, I think I would have double-majored so that I could have founded a major social network before Facebook.  ;)

FWIW, law school also improved my writing tremendously -- albeit in much different ways.
Susan Nunziata   E2 Tech Brief: Software-Defined Network   5/31/2013 11:00:06 PM
Re: People still
@Joe: This is fantastic! Best argument I've heard for majoring in theatre. I hope all those parents who worry about their liberal arts kids are reading this right now and realizing how beneficial this type of education can be for all aspects of your life.

I encourage everyone, of all ages, to explore theatre courses or workshops. My experience with these has helped me tremendously as far as being comfortable in speaking in public, in front of large groups as well as in situations where I need to assert myself.

Thank you for sharing.
Joe Stanganelli   E2 Tech Brief: Software-Defined Network   5/31/2013 10:17:23 PM
Joe Stanganelli
Re: People still
My experiences as a theatre major improved my writing tremendously (all types of writing).

Part of this is due to my reading a lot of David Mamet -- not just his plays, but his nonfiction.  Mamet writes extensively about removing the extraneous when we write, or direct, or otherwise tell a story.  He cites Hemingway's (I think) advice to cut out all the good lines and see if it still works.  My other studies in storytelling reinforced this, as did my directing and playwrighting experiences (both during and after college).

Part of this is due to a history of theatre professor who gave me some essay-writing advice.  He told me that I was a strong writer -- except for my introductions, which were weak.  He advised me to write my introductions last instead of first because there's no way I could know what I'm going to write about (and, thus, how to introduce it) until I've already written it.

And then there was my first playwrighting course, in which we students were tasked with keeping a "compost notebook."  The assignment was to write in this notebook for a minimum of 15 minutes a day (straight), 6 days a week.  Once we started writing, putting pen to paper, we could not stop.  Not to think about what we wrote, not to reread what we wrote, not to correct a mistake or cross something out, not to change something, not to pause to think, not to take a snack break, not for anything.  We just wrote.

The purpose of this was twofold.  First, it helped eliminate our internal editor; often when we write, we pause, come up with an idea, and mull it over excessively, thinking, "No, that's not good enough."  And then the idea never gets written down or explored.  So this allowed me to learn to be more "free" with my writing -- knowing that I can always edit at the end.  (The notebook was called a "compost" notebook because, as our professor put it, it would help us "get the [excrement] out.")

Second, the assignment was based on the premise that writing is an art, and therefore -- like any art -- requires practice (as you would practice drawing, or playing the piano) to get better at it.

Susan Nunziata   E2 Tech Brief: Software-Defined Network   5/31/2013 10:03:43 PM
Re: People still
@Joe: I'd never judge anyone too harshly for what they wore in college. That's a whole different phase in life. My fashion choices back then are highly questionable.

What's more interesting is that you were a theatre major!

What unexpected benefits has your major offered to you throughout your career?
Joe Stanganelli   E2 Tech Brief: Software-Defined Network   5/31/2013 10:03:40 PM
Re: Well Timed
This discussion reminds me of when I was at the Bio-IT conference in April.  I briefly spoke with one vendor who threw dozens of acronyms at me (almost all over my head) in under two minutes.  I pulled myself away as quickly as I politely could.

His was one of the most sparsely attended booths, and he did not return for the third day of the conference.  I kind of felt bad for him.
Joe Stanganelli   E2 Tech Brief: Software-Defined Network   5/31/2013 10:00:21 PM
Re: People still
I sported a goatee (admittedly, a pretty terrible one) for a couple of years in college, but in my defense, I was a theatre major.

Handlebar moustaches are fine, though -- if you're also bald and super muscular.  Or wearing a top hat and a monocle.
Page 1 / 3   >   >>

The blogs and comments posted on do not reflect the views of TechWeb,, or its sponsors., TechWeb, and its sponsors do not assume responsibility for any comments, claims, or opinions made by authors and bloggers. They are no substitute for your own research and should not be relied upon for trading or any other purpose.

More Blogs from John W. Verity
John W. Verity   6/14/2013   6 comments
Many years ago, when much of the Internet's basic protocol -- the IP in TCP/IP -- was getting formulated, 4.3 billion unique addresses looked like more than enough. The world may not get ...
Latest Archived Broadcast
We talk with Bernard Golden about accelerating application delivery in the cloud.
On-demand Video with Chat
Register for this video discussion to learn how tablets can provide true business usability and productivity.
E2 IT Migration Zones
IT Migration Zone - UK
Why PowerShell Is Important
Reduce the Windows 8 Footprint for VDI
Rethinking Storage Management
IT Migration Zone - FR
SQL Server : 240 To de mémoire flash pour votre data warehouse
Quand Office vient booster les revenus Cloud et Android de Microsoft
Windows Phone : Nokia veut davantage d'applications (et les utilisateurs aussi)
IT Migration Zone - DE
Cloud Computing: Warum Unternehmen trotz NSA auf die „private“ Wolke setzen sollten
Cloud Computing bleibt Wachstumsmarkt – Windows Azure ist Vorreiter
Like Us on Facebook
Twitter Feed
Enterprise Efficiency Twitter Feed
Site Moderators Wanted
Enterprise Efficiency is looking for engaged readers to moderate the message boards on this site. Engage in high-IQ conversations with IT industry leaders; earn kudos and perks. Interested? E-mail:
Dell's Efficiency Modeling Tool
The major problem facing the CIO is how to measure the effectiveness of the IT department. Learn how Dell’s Efficiency Modeling Tool gives the CIO two clear, powerful numbers: Efficiency Quotient and Impact Quotient. These numbers can be transforma¬tive not only to the department, but to the entire enterprise.

Read the full report
The State of Enterprise Efficiency in the Virtual Era: Virtualization – Smart Approaches to Maximize Gains
Virtualization is a presence in nearly all enterprise data centers. But not all companies are using it to its best effect. Learn the common characteristics of success, what barriers companies face, and how to get the most from your efforts.

Read the full report
Informed CIO: Dollars & Sense: Virtual Desktop Infrastructure
Cut through the VDI hype and get the full picture -- including ROI and the impact on your Data Center -- to make an informed decision about your virtual desktop infrastructure deployments.

Read the full report
A Video Case Study – Translational Genomics Research Institute
e2 Video

On the Case
TGen IT: Where We're Going Next

7|11|12   |   08:12   |   10 comments

Now that TGen has broken new ground in genomic research by using Dell's storage, cloud, and high-performance computing solutions, the company discusses what will come next for it and for personalized medicine.
On the Case
Better Care Through Better Communications

6|6|12   |   02:24   |   11 comments

The achievements of the TGen/Dell project could improve how all people receive healthcare, because they are creating ways to improve end-to-end communication of medical data.
On the Case
TGen IT: Where We Are Now

5|15|12   |   06:58   |   6 comments

TGen is breaking new ground in genomic research by using Dell's storage, cloud, and high-performance computing solutions.
On the Case
TGen IT: Where We Were

4|27|12   |   06:45   |   10 comments

The Translational Genomics Research Institute wanted to save lives, but its efforts were hobbled by immense computing challenges related to collecting, processing, sharing, and storing enormous amounts of data.
On the Case
1,200% Faster

4|18|12   |   02:27   |   12 comments

Through their partnership, Dell and TGen have increased the speed of TGen’s medical research by 1,200 percent.
On the Case
IT May Improve Children's Chances of Survival

4|17|12   |   02:12   |   8 comments

IT is helping medical researchers reach breakthroughs in a way and pace never seen before.
On the Case
Medical Advances in the Cloud

4|10|12   |   1:25   |   5 comments

TGen and Dell are pushing the boundaries of computing, and harnessing the power of the cloud to improve healthcare.
On the Case
TGen: Living the Mission

4|9|12   |   2:25   |   3 comments

TGen's CIO puts the organizational mission at the heart of everything the IT staff does.
On the Case
TGen Speeding Up Biomedical Research to Save More Lives

4|5|12   |   1:59   |   6 comments

The Translational Genomics Research Institute is revamping its computing to improve speed, storage, and collaboration – and, most importantly, to save lives.
On the Case
Computing Power Helping to Save Children's Lives

3|28|12   |   2:13   |   3 comments

The Translational Genomics Institute’s partnership with Dell is enabling them to treat kids with neuroblastoma more quickly and save more lives.
Tom Nolle
The Big Reason to Use Office

3|18|14   |   02:24   |   46 comments

Office and personal productivity tools come in a first-class and coach flavor set, but what makes the difference is primarily little things that most users won't encounter. What's the big issue in using something other than Office, and can you get around it?
E2 Editors
SPONSORED: Mobile Security — A Use Case

3|4|14   |   04:27   |   16 comments

New mobile security solutions can accommodate a wide array of needs, including those of a complex university environment.
Tom Nolle
Killing Net Neutrality Might Save You Money

1|16|14   |   2:13   |   16 comments

The DC Court of Appeals voided most of the Neutrality Order, and whatever it might mean for the Internet overall, it might mean better and cheaper Internet VPNs for businesses.
Tom Nolle
The Internet of Everythinguseful

1|10|14   |   2:18   |   19 comments

We really don't want an "Internet of Everything" but even building an Internet of Everythinguseful means setting some ground rules to insure there's value in the process and that costs and risks are minimized.
Tom Nolle
Maturing Google Chrome

12|30|13   |   2.18   |   25 comments

Google's Chrome OS has a lot of potential value and a lot of recent press, but it still needs something to make it more than a thin client. It needs cloud integration, it needs extended APIs via web services, and it needs to suck it up and support a hard drive.
Sara Peters
No More Cookie-Cutter IT

12|23|13   |   03.58   |   21 comments

Creating the right combination of technology, people, and processes for your IT organization is a lot like baking Christmas cookies.
Sara Peters
Smart Wigs Not a Smart Idea

12|5|13   |   3:01   |   46 comments

Sony is seeking a patent for wigs that contain computing devices.
Tom Nolle
Cloud in the Wild

12|4|13   |   02:23   |   15 comments

On a recent African trip I saw examples of the value of the cloud in developing nations, for educational and community development programs. We could build on this, but not only in developing economies, because these same programs are often under-supported even in first-world countries.
E2 Editors
SPONSORED: Is Malware Evading Your IPS?

11|18|13   |   03:16   |   4 comments

Intrusion prevention software is supposed to detect and block malware intrusions, but clever malware authors can evade your IPS in these five main ways.
Sara Peters
Where Have All the Mentors Gone?

9|27|13   |   3:15   |   38 comments

A good professional mentor can change your life for the better... but where do you find one?
Tom Nolle
SDN Wars & You Could Win

9|17|13   |   2:10   |   5 comments

VMware's debate with Cisco on SDN might finally create a fusion between an SDN view that's all about software and another that's all about network equipment. That would be good for every enterprise considering the cloud and SDN.
Ivan Schneider
The Future of the Smart Watch

9|12|13   |   3:19   |   39 comments

Wearing a bulky, oversized watch is good training for the next phase in wristwatches: the Internet-enabled, connected watch. Why the smartphone-tethered connected watch makes sense, plus Ivan demos an entirely new concept for the "smart watch."
Tom Nolle
Cutting Your Cloud Storage Costs

9|4|13   |   2:06   |   3 comments

Cloud storage costs are determined primarily by the rate at which files are changed and the possibility of concurrent access/update. If you can structure your storage use to optimize these factors you can cut costs, perhaps to zero.
Sara Peters
Do CIOs Need an IT Background?

8|29|13   |   2:11   |   23 comments

Most of the CIOs interviewed in the How to Become a CIO series did not start their careers as IT professionals. So is an IT background essential?
Ivan Schneider
The Internet Loves Birthdays

8|27|13   |   3:25   |   69 comments

The Internet has evolved into a machine for drumming up a chorus of "Happy Birthday" messages, from family, friends, friends of friends who you added on Facebook, random people that you circled on G+, and increasingly, automated bots. Enough already.