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Software defined networks

Software defined networks or SDNs are set to do for networking what virtualisation and virtual machines have done for servers. There’s a great story explaining them in the Sydney Morning Herald’s ITPro section.

Virtual machines turn a single physical server into what appears as several separate computers. In some cases there can be hundreds or even thousands of virtual machines in one box.

These virtual machines can pop-up out of nowhere in an instant, perform a task or series of tasks, then disappear again.


People in the business use the term spin-up, because that’s what used to happen with hard discs.

In a similar way, an SDN separates network hardware from the controlling software. This means switches and routers can be reconfigured and orchestrated just like virtual servers. They can appear in an instant and then disappear when no longer needed freeing up resources for the next job to come along.

Managing a network this way becomes flexible and dynamic.

Software defined networks, the Next Big Thing

When companies first virtualised servers, it was mainly about consolidating resources. They could save money buying less hardware, running fewer physical machines used less space and would also reduce power bills.

Quickly they found other benefits and the flexibility meant entire systems could be reconfigured at the drop of a hat. That’s probably what will happen to networks. You can expect rapid changes in storage technology as SDN gains acceptance.

Although few New Zealand businesses run their own networks on a scale that can benefit from software defined networks at the moment, you can expect telcos, cloud computing companies and other service providers to use them in coming months.