Jim Duffy over at Network World had an interesting post on IoT and the intersection of SDN, noting that some claim SDN is critical to the success of IoT while others are in the "it's an enabler" camp.

Experts say that SDN, through its ability to intelligently route traffic and use underutilized network resources, will make it much easier to prepare for the data onslaught of IoT. SDNs will eliminate bottlenecks and induce efficiencies to help the data generated by IoT to be processed without placing a larger strain on the network.



My answer is yes, SDN is a major enabler of IoT, as long as SDN includes the entire network, from layers 2 through 7, and not just the stateless L2-4 layers. It's a given that increased data volumes put additional pressure on networks that must be relieved and that SDN offers a means of doing just that. But the network doesn't really process data, it just moves packets around.

Don't read that as "it isn't important" because it is. As IoT Analyst Dennis Ward of ACG Research notes in the article:

Dynamic load management will enable operators to monitor and orchestrate bandwidth changes automatically given the overall load of the network.  This will be ideal for global IoT providers preparing for the expected exponential increase in devices and data, Ward says.

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.

But the problem is that scaling networks and. more importantly, IoT, isn't just about bandwidth and data volume. It's about applications that will also need to deal with those peak waves of data, and that means it's about the services deployed "in the network" at L4-7 that provide for scale, security and performance of those apps.

That bounces back to put pressure on the network - at higher layers of the network, that is. Because those critical services live at L4-7 in the network.



At issue is the tendency to remain stuck in classic SDN land, where SDN means only stateless layer 2-4, with a focus on routing and switching and basic forwarding. While that piece works great for dealing with bandwidth issues and peak traffic, it doesn't address scaling out access or security services, or scaling out the apps themselves in preparation for incoming tidal waves. For that you need to reach up the stack and look to stateful L4-7. These are not second class citizens in the network. They are key services in the critical data path of an application and must be considered equally with the rest of the resources needed to deploy - and scale - an application. 

After all, if you've automated the network to prepare for a data onslaught and increase app capacity, but left the L4-7 services to its own devices (pun not intended, sorry) you're missing a critical step in the process.

Organizations embracing IoT - and make no mistake there are many that already have and many more exploring it - will need to ensure the entire network is operationalized to gain (and keep) the competitive advantage they're looking for from this fledgling technology trend.

That means the entire app value chain - from stateless to stateful network, from compute to storage - must be operationalized through automation and orchestration frameworks. That might mean commercial frameworks like VMware, open like OpenStack or hybrid offerings like Puppet and Chef. The how isn't as important as the what; which is to say how you operationalize the network is less important than making sure you include the entire network.