Software Defined Networking Concepts

Software defined networking (SDN) is an idea that promises to simplify and unify the way that networks are designed and managed. SDN employs an abstraction that separates the control from the data plane and introduces the notion of a logically centralized controller. These concepts provide benefits like increased flexibility in network management, unification of heterogeneous technologies, and lowered operating expenses, which open many opportunities to work on new innovative networking solutions. This chapter is meant to act as a primer on SDN for readers who are new to the SDN paradigm as well as those who are already familiar with its concepts but could benefit from an inspection of SDN's potential, current research challenges, and associated technological trends. The chapter presents the history and the evolution of SDN from early programmable networks followed by a detailed discussion of its building blocks (including controllers, switches, and interfaces) and some examples of SDN application domains. We also provide a short summary of some of the prominent SDN-related activities in industry and standardization bodies and close with a brief outlook for SDN.