Why IoT needs Software Defined Networking (SDN)

Software defined networking (SDN), with its ability to intelligently route traffic and take advantage of underutilized network resources will help stop the data flood of IoT. Cisco has a pretty aggressive IoT strategy, and they place their application centric infrastructure version of SDN at the centre of this. And it makes sense. Software is still the main ingredient that can be used to combat network bandwidth challenges.

Lori MacVittie8 agrees with SDN being a critical enabler, but only if SDN considers all of the network layers from 2 to 7, and not just stateless 2-4. “Moving packets around optimally isn’t easy in a fixed and largely manually driven network. That’s why SDN is increasingly important when data volumes increase and do so in predictable waves. SDN can provide the means to automatically shift the load either in response or, optimally, in anticipation of those peak waves.”

The network challenges in IoT do not stop at bandwidth and volumes of data. Applications will be required to deal with the peak loads of data, so services will be required in layers 4-7 that provide for scale, security and performance of those apps.

Figure 5: Stateless vs Stateful in SDN Application Services [8]

SDN has features that will also be particularly useful. Dynamic load management should allow users to monitor and orchestrate bandwidth automatically on the fly, which will be music to the ears of global IoT providers. Service chaining will enable application specific processing procedures in a sequence fashion to a client’s job. This should ease management overhead in IoT services, as the subscriptions increase globally. One of the coolest features of SDN is bandwidth calendaring which will allow the user to schedule the traffic an application will need at a given time, and when you think of a sensor only wanting to communicate at periodic times, it is apparent that this will be a great asset.

But this cannot happen soon. Data center managers will have to modernize their infrastructures. Once they do, a potential big win would be the ability to create numerous virtual and private networks on top of a single physical network. This would be a big advantage as multiple customers could then share a single network, without risk for their applications and data. However, for this to work, one would need the entire network to be SDN enabled.

When one considers the concept of Network Functional Virtualization (NFV), this path can be traversed quicker. With NFV ready networks, carriers can create services in software, rather than dedicated hardware, essentially allowing virtualized servers to allow these new services. This enables business transformation by moving away from having multiple isolated networks, and one would work with an open ecosystem, a set of virtualized network functions, and most importantly an orchestration layer. This will allow businesses to accelerate with agility in the face of device quantity explosion.

Reference:

8: Dev Central: SDN and IoT article

https://devcentral.f5.com/articles/sdn-is-important-to-iot-if-it-covers-the-entire-network