The orchestration layer of a network performs the role of “network operating system.”  Responsible for separating the infrastructure from the applications, the orchestration layer provides a standard Application Programming Interface (API) to the applications in one direction and to the network in the other.  In some reference diagrams the orchestrator has three functional groupings exposed; Performance monitoring, service assurance and capacity management.

As capacity management fits in the orchestration layer, it is important to draw out more of what the orchestrator is doing.  As the controlling layer, orchestration has to include a number of operations, including service creation, path computation, topology discovery, network state, connection setup, forecasting and trending, performance monitoring and service assurance.

Vendors providing management and orchestrator functionality for services and applications will need to model networks in an alternative way considering a data driven definition of both the network and capacity.  The former is really an SDN enabler.  Once networks can be defined simply by data, any network architecture can be modelled or tweaked in real time.  How the network functionality changes is a defined by the second requirement, the NFV enabler.  Concepts like the Software Define Data Centre (SDDC) should be viewed as applications of this approach.

Capacity management and orchestration are front and centre of the evolution to a true service-enabled virtual network constructed on the principles of NFV and SDN.  Network operators and operators of data centres need to effectively orchestrate capacity to derive the best possible value from infrastructure assets to deliver the most effective capacity management.  Central to this objective is effectively understanding the current and future demands on a network and enabling it to optimise itself in real time to deliver to those demands.