As expected Cisco has announced plans to 'spin-in' its purchased Insieme Networks and base its SDN-countering strategy around that technology offering. That has been confirmed this week with Cisco announcing that it would buy the bit of Insieme that it didn't already own. It also announced some (but not all) of its approach with Insieme, in particular the centrality of 'applications awareness'.

The SDN/NFV movement is about keeping network intelligence in software and using so-called 'white boxes' (generic servers and switches using merchant silicon) where possible. That should deliver huge savings and increases in agility. Cisco's model, of course, is the opposite. All the clever stuff goes into Cisco's 'black' boxes and comes at a steep price.

The SDN pretenders to the Cisco throne might bang on about cost savings, agility, open source and openness, but Cisco thinks the big change network operators and enterprises are really looking for is the ability to define and control services via applications. So it thinks it can continue with its hardware approach (while allowing interoperation with other SDN/NFV schemes, of course) as long as it shows enough movement on its hardware pricing to keep its current customers happy.

So at the core of the Insieme offer is Insieme's Nexus 9000 line of data centre and cloud switches and its “Application Centric Infrastructure” approach. The plan is to offer a sort of "off-white" (magnolia, perhaps) box approach with the Nexus switches which will sport both commodity chips (like white boxes do) and Cisco black box custom silicon, thus offering what might be seen as the best of both worlds: a box capable of working with OpenFlow as well as with Cisco's "application-centric" offerings. In other words it can provision both physical and virtual resources.

With ACI Cisco is making a spirited attempt to head its competitors off at the pass by addressing what it percieves one of the 'real' problems is likely to be associated with advanced programable networks. Its very abstraction.

When a network becomes completely virtual those who must play around with it, imagine it, discuss it, teach it, and so on, no longer have a physical network architecture to feel constrained by. It all gets a whole lot harder - like composing music when, instead of ricocheting about inside a constraining 'key', you are given every note and noise ever heard to play with.

This existential problem was best summed up by Tom Nolle (see his recent interview with Martyn Warwick) who rightly predicted back in June that Cisco would major on the northbound interface to distinguish its looming SDN-alike offering. As he pointed out then in his blog, "...if you can’t carefully operationalize our new and agile virtual world you’ve only invented a new way of getting into deep cost trouble down the line. The complexity of a virtual system is inherently higher because of its additional flexibility and the multiplication in the number of elements."

Nolle continued: "Network operators have already told me that they’re more worried about how cloud applications (including NFV) are operationalized than about how they’re optimized and deployed. The challenges of operations in a virtual, integrated, world are formidable because there are no real devices that present MIBs, and there are elements of application/service performance that don’t belong to any component that you’ve deployed, but to the connections between components"

But one way of re-attaching yourself to a fixed point is via the customer and the "customer orientation". The squishy universe that virtualisation creates can start to gel again.

"You can harp on about the value of SDN in terms of efficiency or better hardware/software innovation or whatever, but to actually defend SDN’s value you have to get back to the place where software starts defining networking. That means you have to face those northbound APIs and the applications that control connectivity and manage traffic," says Nolle.

It's going to be an interesting fight.