Prep for the SDN journey

EnergySoftware-defined networking has dominated the networking discourse over the past couple of years. A complex topic and technology, the SDN concept is still searching for broader understanding as IT looks for ways to streamline network management and vendors work to build momentum for increased deployment. HP has taken up the task of user education, based on the wise assumption that adoption is dependent on familiarity and on user preparation. As the second in a series of business white papers devoted to the subject, Software defined networking. A pragmatic approach to increasing network agility from HP Network Services, has noted, "This is the network of the future, and if you start preparing for it today, then you are in a better position to take full advantage of SDN as the underlying technology matures."

So what exactly is SDN, and why is it the "network of the future"? Definitions abound, but in the white paper, HP Networking has taken an approach to explaining the fundamentals, around which there is considerable consensus. According to HP, SDN is based on the separation of the control plane from the data forwarding planes, which typically reside on the hardware, to allow control of the traffic flow across the network fabric via a software application called a controller. The controller in turn abstracts distributed control planes and unifies them in a central plane to enable programming of the single entity hence the term ‘software-defined networking’. The key to SDN, this centralized programming capability delivers new levels of automation to network management, transforming the network environment from one in which multiple control planes distributed across different routers and devices are individually, and in some cases manually configured through CLI,  to one capable of addressing the dynamic speed requirements of virtualized data centres. With SDN, the network in no longer the bottleneck in user transition to cloud.

Interestingly, HP differentiates SDN from the implementation of virtual overlay networks or virtualized network appliances, arguing that SDN "inserts both service intelligence and application intelligence into the infrastructure layer for a more robust network with hardware-independent flexibility." Hardware independence is a critical feature of HP’s vision of SDN[1]: built on OpenFlow, the open standards protocol developed first by Martin Casado, while a student at Stanford University, HP SDN provides access and openness at the application, control and infrastructure layers to enable effective management across a multivendor enterprise, and to empower users to innovate more independently. As the whitepaper explains, "While innovation in today’s networks is limited by the need for vendor issued updates to individual device software, the qualities of SDN enable you to design new network services at your own pace, either on your own or by working with software providers and/or services partners." The flexibility to determine pace and to work with preferred suppliers to build out a unique user ecosystem is an attractive feature of SDN that addresses the reality of many user organizations. Technology users today have their own agendas that have much more to do with IT budgets, legacy systems, refresh cycles and business needs than with vendor schedules.

HP also differentiates SDN from central network management systems (such as the company’s own Intelligent Management Centre), which can offer network automation, but not the external software control that would allow a user to align networking resources with the rest of data centre infrastructure. In this sense, SDN functions as more than networking solution: it becomes an integral part of infrastructure resources, acting as a "bridge between the network and applications" for dynamic provisioning and ongoing reconfiguration of business application requirements and optimized QoS delivery. The result, according to HP, is business value through greater applications sensitivity and better utilization of networking resources, but also lower TCO through a programming a single entity, as opposed to multiple devices/ports, and reduced need to deploy specific devices for different network services such as load balancing or QoS for lower operating expense.

Ultimately, HP predicts that through programming and automation SDN can help address some of the data centre complexity that has emerged with the new demands imposed by the heterogeneous infrastructure environments, multiple applications and operating systems and mobility requirements of the modern enterprise. Since this is unlikely to happen overnight, HP has provided potential users with some specific advice, and some general guidance that may ease transition to SDN. Altogether, the whitepaper outlines seven steps that users can take to ensure they "own their own SDN journey":

  • Start by assembling a predefined service catalogue with automated workflows that can easily be defined, executed, and maintained and that are independent of changes to technology components.
  • Take a comprehensive SDN view that takes into account changes in governance, processes and skill sets as well as technology to ensure implementation goes beyond consideration of infrastructure capability to address business value.
  • Approach SDN pragmatically, adopting a phased approach rather than rip and replace. This is possible since SDN offers incremental benefits that can be accessed at various points in the implementation.
  • Understand where your network is today by defining the network state and the traffic patterns which may benefit from the impact of SDN.
  • Develop a detailed roadmap for the future that leverages existing investments and identifies appropriate technologies to allow you to achieve your networking goals.
  • Start transforming your management layer now with centralized network management that will support tight integration with the control plane to ensure success of the eventual SDN implementation.
  • Identify opportunities for SDN-enabled products or those network devices that enable the flow of data, particularly at the network or data centre edge and add these to your procurement plans to promote the acquisition of SDN enabled hardware in technology refresh.


Sound like a tall order? More detail is available in the Software defined networking white paper, along with information on HP services and technologies that can support users at each stage in the SDN journey.

For more information, contact HP.


[1] HP was founding member of the Open Network Foundation, an early adopter of the OpenFlow protocol, and continues to support open source SDN initiatives such as the Linux-based OpenDaylight project.