Software-Defined Networking 2

Preface

Due to the emergence of new kinds of communication and networking technologies (e.g. the Internet of Things (IoT), mobile trends, network virtualization) and the rise of many advanced services (e.g. real-time services, e-health, multimedia, smart cities, gaming) supported by these technologies, today’s networks – considered relatively static, “ossified” and “challenging to manage”– are no longer suitable to handle the complexity and diversity of network information being disseminated in today’s modern and dynamic networking environments.

There is a strong need to shift the current network architecture to a new model that adapts to such changes and leverages new control strategies to ease network management and automation, leading to better network performance and lower operating costs. In this context, software-defined networking (SDN) has emerged as a new networking paradigm that decouples network control and forwarding functions, enabling the network control to become directly programmable and the underlying infrastructure to be abstracted for applications and services.

SDN attempts to centralize the network control, thus offering improved visibility and flexibility to manage the network, optimize its performance and reduce its operating costs. However, centralized SDN designs, in which the control plane logic is physically centralized in a single software component called the SDN controller, present numerous challenges including the issues of control plane reliability, ...