Lippis adds, however, that a lot of the early vision about SDN's role is being put forward by vendors that are just guessing what people will use it for. "It's not until SDN is in the hands of IT architects that real use cases will start to emerge."
Consider early user Indiana University. It didn't want to pay $100,000-$200,000 for a load balancer that could sit on the school's 10Gbps Internet trunk and parse out traffic to multiple intrusion detection systems for analysis, so it got creative.
"We saw this was an obvious use case for SDN and OpenFlow," says Steve Wallace, executive director of InCNTRE, the Indian Center for Network Translational Research and Education. He says they hired a couple of grad students to develop software for an OpenFlow controller that instructs a $40,000 OpenFlow-enabled switch to handle the load balancing task and have been reaping the benefits ever since.
Cost savings, in fact, is one of the potential benefits of SDN. Undoubtedly other organizations will discover more SDN niche applications that deliver savings, and longer-term simplification of the network is expected to lower opex costs, but it is less clear if SDN also results in reduced capex costs.
In an article about SDN in The Economist (yes, The Economist, showing just how far this stuff is spreading), Chris Weitz of Deloitte Consulting was quoted as saying "firms using SDN can save up to 50% on their networking bills ... some of the savings [coming] from cutting out 'carbon middleware,' as network engineers jokingly refer to themselves, and from buying more basic — and thus cheaper — hardware."
The hardware can get cheaper, the rationale goes, because with SDN the smarts are embodied in software and shifted to the centralized controller.
But is capex the problem that needs fixing?
"I think what's driving this is operational costs, not capital costs," Lippis says. "In fact, some say the capital costs are irrelevant. They say, 'If someone gave me $2 million worth of equipment for free, I couldn't take it because I can't afford to manage it.' So if the equipment costs zero they're not going to take it, and they won't take it if it's really expensive, so the vendors really have to deal with the operational piece of this."
Over a three-year period, capital costs represent 25% of networking total cost of ownership, Lippis says. "So it's already a relatively small number, and if it goes to 12% because SDN makes it possible to use lower cost equipment, is that a big deal?"
Leary adds that simplification doesn't necessarily equate with low cost. "Leonardo da Vinci once said, 'Simplicity is the ultimate sophistication.' Just because something is simple doesn't mean it's not incredibly sophisticated underneath. As the network becomes simple, the network devices and controllers grow that much more sophisticated."
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