SDN: When The Hardware Becomes A Little More Soft

I grew up in the dedicated hardware world. Switches and routers that – sure - included processors and a little bit of memory.  Devices with pretty basic operating systems that kept track of addresses to move content around on a network, making sure stuff gets to where it is supposed to go. Nothing fancy but it has worked pretty good with the build out of the internet over the past 20 years or so. 

Today, we’re seeing a pretty major shift to what people are calling Software Defined Networks (SDNs). You may have seen SDN also referred to as elastic computing and/or elastic networks. The idea with SDNs is to not just try and make the network more efficient but also make it flexible and scalable. The concept is pretty simple and SDN Central explains it pretty well:

Software Defined Networking (SDN) is a new approach to designing, building and managing networks. The basic concept is that SDN separates the network’s control (brains) and forwarding (muscle) planes to make it easier to optimize each. 

In this environment, a Controller acts as the “brains,” providing an abstract, centralized view of the overall network. Through the Controller, network administrators can quickly and easily make and push out decisions on how the underlying systems (switches, routers) of the forwarding plane will handle the traffic.

So, you’ve got a smart controller looking at the entire network including applications running on the end devices. The controller communicates with network controlling devices (switches and routers), adjusting and optimizing the network to real-time conditions. Sort of like a maître d / head waiter in a busy restaurant.

For providers (Verizon, AT&T, etc) , SDNs reduce equipment costs and allow the networks to be more efficiently controlled. These networks are optical fiber-based and that has me pretty excited with my new position at the NSF-funded OP-TEC ATE Center. 

Centralized, programmable optical networks that dynamically adjust to changing requirements. Nice. I’ll be writing more about SDN and a number of other optics based technologies in future posts.