Everything now in IT and IP has become 'SDN-ified' or SDN-ready.  But it doesn't all mean the same thing or have the same overall impact. 

To mark the one year birthday of Nuage Networks (our SDN in-house start-up) I feel compelled to put my fingers to the keys and explain it from my level (all apologies to the engineers: I know I have left out many details in my effort to make it understandable). 

One secret I have learned is that in order to understand where a new technology is going, we must look at how things have been done in the past and talk about the limitations of the existing technology.  First lets talk about 'the network.'  As it turns out when you are looking at a web site via your mobile phone - you are actually transversing a number of networks. You may start out on the mobile networks then get connected to the Internet via a wire network, visit the web site on a server most likely in a data center and then the reverse.  It usually happens easily and without trouble and you don't think about.

Now remember when you have tried to buy concert tickets to the hottest show in your city - sometimes the web site crashed and you lost connection or imagine you have decided to have a global meeting by video and as your employees start to log in the connections are overloaded and only a few of them were able to hear the CEOs message. To avoid this if you are running an IT operation you may have to buy even more network capacity then you might need to ensure there is no downtime .  Think about the impact of businesses that rely on moving around massive pieces of data - healthcare or the financial industry - or even web companies like Amazon whose entire business rests in connecting people with the things they want to buy in a virtual world.  Guessing right (or wrong) has some pretty big impacts.

Now let's talk about why. It actually all has to do with network protocols (I think of that as a fancy way to say languages). In a data center (or the IT world) the common language spoken is IP. But in the telecom world there is another set of protocols that tell the network what to do.  Smart people have found a way to make the connection - but even today that connection has to be made manually - with a person adding the connection to one specific server via the IP address.  Our Bell Labs President and CTO Marcus Weldon uses a nice example that I can understand comparing the pre-SDN world to the world of old 'switchboards' in telephony from 70 years ago.

Before SDN switchboard operators needed roller skates to keep up

Back then (even way before my time) each telephone user was manually assigned a (short) number that defined you and the name of the exchange your phone was attached to. To make a call you had to call an operator who manually made a connection to the person you were trying to call.  It was a manual process that required human intervention to connect things. 

This is somewhat how things are working when you want to connect between a data center (IT world) and the IP world (the network world). You are given a short number (a VLAN) that is manually pushed to the switch by an operations person who helps you can connect to it locally .  If you want to connect to another application  that is not local this requires someone to map your local VLAN into an IP tunnel and then to the VLAN used by the other application.  And since this can be hard to figure out, it take may take time - sometimes days or even weeks or months to make this happen.  Another good example from our Nuage Networks team is this: imagine putting your ATM card into a bank machine and being told that you will get your money eventually - doesn't cut it in today virtual world. 

SDN automates all of this by automatically assigning addresses (VXLAN labels) that have a global scale to each application and then allowing these addresses to be advertised and then mapped into IP/MPLS tunnels between anywhere and anywhere.  We are in essence moving from the manual switchboard era to automated global dialing of any application to any other application.  Just imagine for a minute a manual switch board operator trying to keep up with today's mobile conversations - my three kids would keep someone very busy with all of their texting and Instagram postings.J  But having an even bigger impact is a massive industry shift taking place as well.  A huge driver for SDN is the massive IT virtualization and Networks Functions Virtualization in the telecom industry as well, it just must be more automated to operate in our collective 'cloudy' future.

So you may be thinking - so what?  How does that change anything about my world or my life? Does it make anything better?   Without knowing exactly what an SDN planet will look like I know the answer will be 'yes.'  Today we are limited in our minds but what we think is possible based on the structure of today's networks.  Just like in my teen years if you told me I would be able to find almost any sort of information I wanted from a device I would carry with me including - nearest restaurants, cool things to do in a particular city and how to get to where I wanted to go - I would have said you were crazy.  

The initial uses of SDN will be by companies with the need to move a lot of data (banks, hospitals, media companies) but I think once these grab hold of this flexible environment then the innovation will happen - this may be new applications, improvements to old applications and perhaps  create entirely new industries.  When you couple that with things happening in wireless with 5G perhaps after all this time the network will have no limitations - and will essentially become invisible and the world will continue to grow smaller.  We will have no limitations and can connect to the people and the information we want and need truly anytime or anywhere.  If you thought the last 10 years were wild - hold on for the next 10.

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