Software defined networking (SDN) is almost certain to remake datacenter infrastructure in the coming years. The mere fact that it finally brings a layer of virtualization over rigid hardware platforms will enable the kind of dynamic network environments that technology gurus have been predicting for years.
But is this enough? Is it possible that the enterprise will still face the prospect of disjointed, uncoordinated network environments even as the demands of unified communications and collaborative data environments stack up? Unfortunately, the answer is yes, considering the very notion of what is and is not the datacenter is becoming increasingly hard to determine.
If you take a look at many of the deployment options for SDN, it certainly seems like all the APIs and related technologies are in place to produce an effective environment for virtual network operations. For example, Stanford University, which is credited for spearheading the OpenFlow protocol, provides guidance for deploying the system on production-level enterprise environments, across multiple PCs and NetFPGA configurations and even on a single PC where OF environments can be emulated for application development and other purposes. In fact, the school says enterprises should be able to establish complete OpenFlow environments using technology from multiple vendors in a single day.
It sounds good, until you start to ask questions about multi-datacenter, colocation or cloud environments. Precious few large enterprises, and even a growing number of small and mid-sized ones, are contained within a single datacenter anymore. Is it possible, then, to extend OpenFlow beyond the datacenter, effectively providing a single abstract network across both packet and switched circuit layers?
Not yet, but this little flaw hasn't escaped the notice of some key networking designers, particularly since the giant telecommunications firms around the globe are keen on implementing SDN on their architectures as well. ADVA Optical, for one, recently joined the Open Networking Foundation (ONF), lead sponsor of OpenFlow, with the expressed intent of porting the protocol to the optical domain. The company has already established a test bed at the University of Essex aimed at developing OF control mechanisms that work on both packet and optical wavelength switches. If all goes well, the result will be a fully automated SDN environment that can travel wherever enterprise infrastructure takes it. As the company envisions it, SDN on the optical network will enable a truly integrated, end-to-end virtual network, placing all data communications under the wing of a single, global switching architecture.
In fact, a number of top carriers met in Abu Dhabi under the auspices of the International Telecommunications Union in part to map out SDN development for circuit switched networks, with an eye toward extending network virtualization across access environments, mobile backhaul, metro links and practically anywhere else that wired or wireless infrastructure exists. The process is barely out of the planning stage, however, as the organization is only now setting up a Focus Group to identify ways in which existing SDN efforts could be tailored to carrier-class environments.
Meanwhile, one telecommunications carrier says it is already up and running with an OpenFlow service. Japan's NTT Communications announced over the summer that it's cloud services in Hong Kong and Japan are available with OpenFlow networking capabilities. While this still does not extend the protocol over the switched portion of the network, it does enable multiple cloud environments to appear as a single OF infrastructure, streamlining network footprints and adding a high degree of flexibility for services like disaster recovery.
Restricting SDN to the datacenter is kind of like buying an expensive new sports car but driving it only on a race track. Sure, it goes fast and you can do a whole lot more with it compared to a normal car. But until you take it out on the open road, you are simply limiting your ability to make the most of your investment.
Once SDN is implemented on both carrier and enterprise infrastructure, data communications will never be the same again.