Software Defined Networks (SDN) and Network Functions Virtualisation (NFV) are together, about to meet the demand for true network virtualisation.  The demand is there, but the key issue is how service providers can deliver the best SDN experience?  It is fundamentally important to recognise the role of capacity management.

Capacity management is only one aspect of a managed virtual network, but it is an important part of orchestration.  Adaptability is a primary feature of a virtualisation and from a capacity management perspective, the ability to respond to changes in network infrastructure is vital.  The time scale of adaption to these changes has, historically, been too long.  With the right technology now available, the network needs to be abstracted.  The network is simply a vehicle for the support of services and applications and the generation of revenue.  With this approach it becomes easier to rapidly reconfigure the network model by changing the data required to model it.  This delivers a Software Defined Network.

A data driven definition of capacity, facilitating a more detailed level of control, is required to effectively manage capacity on a rapidly reconfiguring network.  Capacity itself and capacity as a requirement also needs to be data driven.  This has been achieved in the past through traditional “Intelligent Networks,” where service function was built from smaller building blocks, but the equipment those services ran on was still bespoke.  Once capacity has been abstracted, services or applications can utilise required capacity without constraint.

Capacity management is often thought of in an operational context: how to manage services within an infrastructure or how to repair a service when there is a fault.  Whilst this is very important from a tactical perspective, other capacity management use cases need careful consideration, particularly around optimisation and constraint management and planning based on new load demands.