SDN. A critical enabler of IoT

Sreekanth S

Software defined Networking (SDN), one of the most disruptive technologies in networking in recent times, has already marked its way in the industry. As per the latest report published by Allied Market Research, SDN market is expected to reach $ 132.9 billion by 2022. Internet of Things (IoT), on the other-hand will make 21 Billion devices connected by 2020, meaning they will be on the network. So, the natural question arises- how these two very promising technologies supplement each other?

If we look at the expectations of IoT on network, the key ones will be - handling the data from the exponential number of devices, policy control for actions and end-to-end security of information. Let us take the example of a connected medical scenario. Consider that the hospital machinery as well as the patient end point devices are both IoT enabled and connected.

The data types which are exchanged include medical images and videos which are bandwidth-heavy on the network. Depending on the real-time load of the network, hospital and other medical enterprises need flexible bandwidth. Since these are strictly personal data, end-to-end data security is required. The security policy has to be personal and associated with end points. If the hospital machinery (portable imaging) is getting moved around, then the machine needs to get connected in the new spot immediately and the same network policies and controls it had in the earlier network need to be pushed dynamically to the new spot as well.

As you can see, all these requirements are all elastic in nature which requires the network to respond in an agile way. These are either very cumbersome to be done using traditional networking methods or is not possible at all.

The fundamental benefit which SDN brings on the table is that it makes the network programmable and elastic. Traditionally, the network elements are managed by configuring them for a particular network design. Changes in the network are done through configuration managers reaching out to each network element.

The dependencies are usually resolved manually. This makes the changes non-real-time and less dynamic. In SDN, the controller has a centralized view of the network. This allows having data-model or networking template-based configurations and policies to be pushed to the network quite easily. Also, the controllers exposes programmable interface through APIs which enables programs to be written to control the network.

Some of the capabilities which SDN brings enhancing the existing traditional network are:

o Application awareness in the network: - Through the remote control plane of SDN controller, application awareness can be achieved. Networks can be made to respond to specific application demands like, routing the traffic differently for a particular application during network congestion.

o Dynamic policy injection:- Centralized and optimal policy injection to a network element or network as a whole is possible in SDN networks.

o Elastic band-width demand handling:-SDN-enabled branch office as well as edge routing and switching devices can react to variable bandwidth provisioning requirements.

o Dynamic QoS :- SDN enabled switching elements can respond to dynamic QOS remarking requests and thereby allowing dynamic preferential treatments of packets in the network. Further, SDN controller can add application awareness to this making it application aware preferential treatment.

Let us come back to the connected medical scenario and try applying some of the above capabilities. Application awareness helps the network to identify that the heavy data is coming from a critical medical device.

If the network is running low on bandwidth at that point of time, either a preferential application aware routing or QoS remarking and treatment can be dynamically done. If the hospital knows that there particular days of the week or hours of day there are heavy usage of the data exchange (For Eg: remote patient consultancy), they can subscribe for elastic band-width based on the requirement through a simple to use user interface. Finally, to secure the end-to-end data, SDN-enabled adapters are available which can exist close to the end devices and dynamic policies can be injected at real-time. These adaptors also makes the portable medical devices connects to the network very fast and down-load the policies automatically.

Conclusively, SDN technology enables the network better for IoT. It provides the agility and elasticity which IoT demands to the network. Moreover, it provides an open environment for application developers to develop innovative tools and software connecting IoT use cases. Precisely, both these technologies supplement each other in bringing us a better world.

(Sreekanth S is Principal Technology Architect at Infosys. Views expressed here are of the author and CyberMedia does not necessarily endorse them.)