Software-Defined Networking (SDN) is a method of decoupling the software and algorithms that define the networking control plane from the underlying hardware that manages the forwarding plane. Additionally, Network Function Virtualization (NFV) is defined as providing network functions that run on vendor-agnostic hardware. NFV describes virtualizing network features typically found in layers four through seven of the stack. These two paradigms provide the industry methods to build, scale, and deploy significantly complex network architecture in a very flexible manner. Preceding all, this greatly reduces enterprise cost in network infrastructure since most of the services can run in the cloud.

Why is this important for devices at the edge and where does it fit in with the IoT? We have spent a good deal of this book detailing data movement from a sensor to a cloud, yet have taken for granted how the overall inter-networking infrastructure will scale to a billion additional nodes on a network. One needs only to ask an IT administrator to put an additional million endpoints on a corporate network where the nodes are heterogeneous, in remote locations, and some moving in vehicles to understand the impact on the overall networking infrastructure. Traditional networking does not scale, and we are forced to consider alternative means for building large networks with minimal impact and cost.