Quite simply, Software Defined Networking (SDN) is the single most significant innovation in computer networking in the last 30 years. Seriously it is a game changer. But most people either don't realise it's true potential or they dismiss it as a passing fad. In this 3 part series we are going to explain what SDN is, how it works and how you can get started learning about this amazing technology. So let's start with an analogy -
A network is basically a set of pipes (cables) and data flows through these pipes the same way water does, in one end and out the other. To regulate the flow through these pipes there are a number of valves (switches and routers). Your job as a plumber (network administrator) is to add new pipes when required and upgrade the pipes that become too small with larger ones. But the problem is every time you change the pipes you also have to adjust the valves, individually, by hand. Not only is that time consuming but it is also prone to errors and getting it wrong can be disastrous. Too low and people don't get the amount of water they need, too high and water is wasted or things stop altogether. Now imagine if you could program these valves to adjust themselves, to automatically open and closed based on usage. Add a new pipe and the valves automatically compensates, spring a leak and they automatically close. How cool would that be? That's basically what SDN is, the ability to program your switches to automatically compensate for changes on your network. This goes way beyond things like QoS and ACLs, we are talking about both proactive and reactive changes based on almost any criteria. Because of the way that SDN works, which we will cover in part 2, you not only have access to the packet headers but also the actual payload. This means you now have complete control of every single packet on the network, at a byte level. Just think what you could do with this power, the possibilities are endless!
Stay tuned for Part 2 were we will explain how SDN works and the technologies involved.