It all started with the notion of creating a Japanese version of Amazon Web Services.

Well, you know how those things go. When you start developing it can lead anywhere and it led Midokura - sort of a Japanese contraction meaning Green Cloud - to drop the whole Amazon cloning bit and concentrate on network virtualization, which is core to the cloud.

The start-up thinks it's got a disruptive approach, but of course that's what all the boys say.

It's supposed to remove the barriers common to traditional networks and provide multi-tenant scalability, flexible workload placement and mobility. Enterprises using this approach might expect dramatically reduced network complexity and lower costs.

Midokura officially entered the US market Monday with MidoNet, a distributed decentralized multi-layer software-defined virtual network solution specifically designed for Infrastructure-as-a-Service (IaaS) in hopes of dislodging Nicira from its new found perch inside of VMware.

The company wonders why VMware didn't keep looking after it sighted Nicira. It claims it can do way more than Nicira like routing, security and L3. Still VMware spent $1.25 billion to acquire Nicira.

MidoNet virtualizes the network stack for cloud platforms like OpenStack.

It imagines service providers might use it to ward off Amazon and says enterprises simply need it.

It figures it adds the automation that significantly reduces the human cost of managing the network (otherwise known as opex), and impacts the overall economics of cloud computing by simplifying network requirements (to wit, capex).

Midokura, which has raised $5.5 million, was co-founded in January of 2010 by CEO Tatsuya Kato and CTO Dan Mihai Dumitriu who assembled a team from Amazon, DreamHost, Fulcrum Microsystems, Google, NEC and NTT with research credentials from Cornell, EPFL and Stanford.

"We originally set out to build a public cloud in Japan, but quickly realized there were still networking challenges to overcome," Dumitriu says. "Operating an efficient cloud required a whole new way of thinking around how network services should be built. Our team is uniquely qualified to disrupt IaaS networking, and two years in, MidoNet is ahead of the market."

It takes an overlay-based approach to network virtualization that sits on top of any IP-connected network and pushes the network intelligence to the edge of the network in software.

MidoNet virtualizes network functionality for IaaS cloud management systems like the Essex version of OpenStack and provides a Quantum plug-in as well as Nova network drivers for fully virtualized network functionality with OpenStack clouds.

It figures it's being clever to line up with OpenStack, which is already in production with some of the world's largest enterprise organizations.

As an advanced software-defined networking solution MidoNet uncouples the cloud from the network hardware to create an intelligent software abstraction layer between the end hosts and the physical network.

This abstraction layer lets the network operator move existing multi-vendor physical network appliances into a software-based virtual multi-tenant domain. So the underlying hardware can be disparate, multi-vendor networking gear and it only needs to be configured once (on the installation of the cloud).

It says existing networks are difficult to provision and scale and current cloud networking models are inherently insecure and not at all resilient to failure.

With MidoNet, cloud users can manage and configure their own virtual networks centrally. Since everything is happening in the software or virtual layer, the physical network doesn't have to be re-configured as the virtual network dynamically changes.

MidoNet is currently in beta with early access customers, partners and developers and should have its 1.0 version out in February or March. At that point it should have figured out its pricing.

Midokura has 24 people in Japan, Spain and the US.