I have read many predictions recently that SDN (Software Defined Networking) is the next big thing in IT. Wrong. It is not. It is just a small piece in a bigger story. And just looking at SDN is not sufficient.

The next big thing is SDCI – Software Defined Computing Infrastructure. This is about “software-defining” everything. Hardware virtualization – “software defining hardware”, so to speak – is a reality. Software Defined Storage is becoming increasingly popular. SDN is another element. A number of vendors, such as VMware, talk about a Software Defined Cloud Datacenter. I don’t like that term, because the “Cloud” element might be nice from a marketing perspective, but tends to narrow things down to a specific form of Computing Infrastructure. So I will use SDCI for now.

When looking at SDCI versus SDN, claiming that SDN is the next big thing is like inventing a locomotive but no rail infrastructure. It is only about solving a portion of the problem, from a technical, network-centric view.

However, SDCI is far more than that. It is about managing how business services are operated on a flexible computing infrastructure, which must include all elements of this infrastructure. It is about defining the policies for the entire infrastructure. This is an interesting challenge, because it is not about network, storage or other technical policies anymore, but about translating the business policies. Regulatory compliance, security requirements, availability, performance, but also the willingness of business to pay for a certain level of service – all that flows into policies that define how infrastructure is used and how to balance various requirements.

SDCI also will revolutionize security, in particular network security. In dynamic environments, there is no place for traditional firewalls anymore, but there are fantastic new opportunities for securing information. Such infrastructures allow us to manage security consistently across “machines”, storage, and network, in the context of business policies and in the context of identities. Instead of having multiple disparate approaches to security – a little bit of firewall here, a little bit of endpoint security here, some IAM there, etc. – we are heading towards integrated security. This integrated security still can be layered, but it will be layered in an integrated manner, unlike “layered” security today, which means using multiple levels of disparate security where no one really knows how good the combined result really is – just because there is no integration, no consistent view, no consistent policies.

The security aspect is another reason why SDNs for themselves are not what we need. SDNs are about continuing segregation. They allow us to repeat mistakes on a higher level. SDCI allows us to do things better. That’s the reason why SDCI is the next big thing – and it will become a real big thing.