How To Explain Software-Defined Networking To A Five-Year-Old

Software-Defined Networking (SDN) is seen as the next evolution in networks, freeing enterprises and service providers to upgrade their networks by deploying software rather than needing to replace their hardware – accelerating innovation and reducing cost.

Many of the biggest names in IT are pushing SDN as the future, including Cisco, HP and Huawei, but the world of SDN can be quite daunting if you’re not a networking expert.

We asked the industry to simplify the case of SDN by telling us how they would describe it to a five year old.

Farhad Ghoreishi, marketing manager at HP Networking EMEA

“Imagine a teacher instructing a group of pupils to go to a particular classroom in a single file. The pupils will do exactly as per their instructions without needing to interpret what the teacher has just said or work out themselves what they need to do – they will just do as their teacher instructed.

“When the group of pupils need to do something different, e.g a fire drill, the teacher simply gives a different set of instructions, telling the pupils to go to the playground, find their own teacher there and wait with him. The instructions don’t need to be explained individually to each pupil; the pupils don’t have to puzzle over what the teacher wants them to do – it’s all straightforward. Once the drill is over, the children can go back to the classroom, ready to receive the next set of instructions.

“Just as in the example with the pupils, decision-making is removed from the hardware switches in SDN, and is given to a software which controls decisions centrally. Switches just do what they are told according to the rules given by the central controller at the time. This way, network administrators can shape network traffic more easily in order to respond to different business needs.”

Joy Gardham, regional director EMEA West at Brocade

“A new technology called SDN is allowing businesses to control their information better than ever before.  Materials such as images, emails, videos and documents all regularly travel across our IT networks and, often, there is too much for the network to cope. As a result, delays and other problems are caused, just like when too many vehicles try to go down the same road; you end up with a traffic jam!

“SDN makes the whole IT network much smarter, meaning all of the information will be directed to where it needs to be as fast as possible, without any delays. What makes SDN even better is that it is also less expensive and more flexible, so as businesses interact more and more with their data, the network will always be able to cope.”

Nathan Pearce, F5 Networks

“SDN is like having the power to make new things, at the touch of a magic button – or even just by thinking about it! Imagine having a big shiny button on your bedroom wall and every time you want to do something faster or in a different way, you just press it and it happens.

“Just think, if you want to get to school faster, you could hit the button and a speedy slide from your bedroom window to the school gate appears. Or if you want the game you’ve ordered to arrive faster, just hit the button and, quick as a flash, the world’s fastest car drops off the delivery man with your new game!”

Brent Lees, senior product marketing manager at Riverbed Technology

“SDN is like when you get your first bike. It works and pedals along, but as you grow up, you want it to be faster and do more. As you add accessories to make your bike go faster and perform better, you will also grow, so need bigger wheels and accessories. You might not need reflectors in the daytime so you can take them off and replace them with beads on your spokes to show off in the day, but can swap them around again as needed.

“SDN lets companies adapt their computer networking in much the same way. It makes it easy for an administrator to see what is needed by workers and when. As a company grows, the administrator can make the amount of apps needed larger and if new technology comes along, they can add in and take away apps to make their workforce more efficient.

“This is completed by separating the system that makes decisions about where traffic is sent from the underlying systems that forward traffic to the selected destination. The result?  Networking is significantly simplified.

Donna Airey, Fasthosts

“Software defined networking (SDN) works like an orchestra giving a concert; you get the overall result of some lovely music (which everyone listening is interested in), dig deeper and each person is busy playing their own small part of the piece.

“Alice plays the oboe. Imagine that she’s got her own music in front of her, as well as a copy of everyone else’s. Before she can play her own part, she reads everyone else’s so that she knows which note to play when but if someone else plays a wrong note (or doesn’t play one at all), she’s going to lose track of where she is and might miss her note too.

“The real problem is that everyone else in the orchestra all have to the same thing, so there’s a much bigger chance of something going wrong somewhere. Luckily for Alice, she doesn’t have to worry about that because the orchestra has a conductor. The conductor ensures that everyone plays their notes at the right time (including herself). The conductor has the score so he can see what all the players should play and when they should play it as well as telling them to get louder or quieter, faster or slower and all while they play.

“That’s basically what happens with SDN. You do the set up in one place and that then sets all your other devices up with the instructions they need to work together. When you then want to change it, you make the change in your software and it then makes sure that all the devices know what they need to do now.”

Stu Bailey, founder and CTO of Infoblox

“Think about the tablet you use to watch videos and play games, or the phone your Dad uses to check his email or the laptop your Mom uses for work. These are all different kinds of computer. Imagine each of these computers is a city full of people doing different things.

“Today, these cities are connected by highways with cars carrying people back and forth, so one computer can talk to another. These highways have stop lights and traffic jams and car crashes that slow things down. Now, let’s imagine each computer city has a magic balloon around it.

“When ten or twelve or even a thousand computer cities want to talk to each other, the people inside make the cities float around and find each other! No more highways, no more cars, no more crashes. As long as two magic balloons are touching, the people inside can talk and visit. This magic world is called Software Defined Networking, and it’s how computers will talk to each other before you’re in high school.”

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