Software Defined Network (SDN) and Network Functions Virtualisation (NFV) are the most established components of network virtualisation.  Network virtualisation provides network operators with the ability to obtain more value from data centre assets.  When deployment and redeployment of network assets and functionality meet demand and this takes place completely through software rather than human control, true virtualisation will have been achieved.   Virtualisation has become essential to effectively support current business models, which are more data intensive than ever before.

Network virtualisation has evolved from the convergence of two industries, each with a language of their own, facing the same challenge.  The Data Centre community has been moving toward reusable assets to provide “virtual machines” to users that can rapidly be configured.  The telecommunications operators, however, need to provide new services and functions dynamically, but to an aggressive timescale.  Both have the same objective: to be able to deliver a virtual network that can be configured and reconfigured dynamically without constraints of geography or hardware.

SDN was spawned from research collaboration between Stanford University and the University of California at Berkley.  NFV was a term launched by seven of the world’s major service providers (the ETSI ISG).  There has recently been a move towards commoditising equipment in favour of creating a virtual network that can be reconfigured as necessary, in other words SDN.  SDN networks still provide key network characteristics like reliable transport, protection under failure and network wide service functions, but they do so in software, so rapid configuration can be accommodated.

The movement towards network virtualisation and the resulting convergence of NFV and SDN demonstrates an unusual opportunity to bring IT and telecommunications industries together.  IT and telecommunications capacity planning functions have traditionally existed in very separate silos, using their own processes and methodologies.  With NFV, the consolidation of IT and telecommunications capacity management functions is needed to match overall capacity and business demands, as well as to be able to obtain true end-to-end visibility of the networking real estate.

The journey to SDN, in terms of virtualisation are the network “as is” with minimal adaptability (old school) and the nirvana of a Self-Organising Network (SON) that can adapt on the fly to changing demands.  The reality will be a hybrid and one that may last for many years due to depreciation costs, experience and risk aversion.  Managing the transition to a virtualised network will require customers and vendors to adopt practices from both the telecommunications and data centre worlds.