SDN. The old future ?

Software Defined Networking (SDN), Software Defined Data Centers (SDDC), Software Defined Storage (SDS). A lot of buzz words and is it really something new ? Let’s focus on SDN. What is the problem and what is SDN resolving.


More then 15 years ago I was a networking guy. At greenfields I had to deploy sometimes 20 switches and some routers. Ofcourse in the beginning you did the configuration all manual. Later I startet to use some “scripts“. Now it was just a matter of copy and paste for the configurations. When the company I was working for noticed that we need some monitoring tools, we had a networking tool which make my life way easier to deploy new sites. I had a good look at all the switches and I had a GUI to see what was happening on the network. Of course when there were some troubles on the network, I had to go to the CLI to fix it.

With the network, the (good) network guy didn’t had any problem. The problems started when other guys wanted to control the network, because applications are now a days “important”. Everyone wants to have a network that is running 24/7, so every manual interference can mean downtime due to configuration errors.

Now there is SDN. Some vendors say it’s hardware independent, but I don’t believe that. The SDN software talks to the hardware. The hardware can only understand that language if there is a conversion between SDN and the hardware language. This could be API’s or just scripts/macro’s. Is SDN the holy grail right now ? I don’t think so. Yes, it could make your life easier but who’s controlling the SDN software ? The networking guys or the application/server guys. Has SDN the option to control all Qos of the application and who got the knowledge of this. Why would you give Qos to an application which isn’t video or a voice application ?

popMy opinion is that SDN is just a marketing story. It’s no answer to a problem. It’s just the evolution of the applications we already had 15 years ago. Sometimes I wonder what the ROI case is for SDN. Yes, I understand for really huge enterprise companies, but for a “normal” dutch company I don’t know. How many hours would it take to configure SDN and what is the value then ?


SDN is the new way of Network Automation and we had the tools already for ages.

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