The Journey to SDN: A Peek into the History of Programmable Networks

Abstract
This paper proposes to do a survey and study of the state-of-art programmable networks with a focus on SDN. It will present a historic outlook of programmable networks from early concepts to very recent progress. This is followed by a study of SDN architecture and the OpenFlow standard. Currently available options for implementation and testing of SDN-based protocols and services are also discussed. SDN applications for current and future are also examined.
Keywords:Software-Defined Networking, Data plane, Control plane, Mininet, Virtualization.
I.Introduction
A typical computer network comprises of a huge number of network devices such as routers, switches and various types of intermediary devises such as a firewall which will also manipulate traffic though it is not for packet forwarding purposes. Many complex protocols are implemented on these intermediary devises. Network events and applications are managed by network administrators by configuring policies. This is done manually by transforming the high level-policies into low-level configuration commands which will adapt to the changing network conditions. For achieving this very complex tasks , very limited tools are currently at their disposals. Because of that, network administration and fine tuning of performance is quite challenging and thus error-prone .Vertical integration of network devises aggravates the challenges faced by network operators and administrators. “Internet ossification” is another almost overwhelming challenge encountered by network practitioners and researchers. Very large deployment base and the fact that now computer network is considered as one of our society’s essential infrastructure (like power and transportation services), makes it extremely difficult for the Internet to evolve in terms of the physical infrastructure as well as its protocols and performance. Present and future Internet applications and services are becoming progressively more complex and demanding. This makes it crucial that the Internet be able to evolve to address these new challenges. The paper is planned as in Section 2, begins by saying about Literature Survey. Section 3 illustrates on overview of SDN architecture which describes the switches and Open Flow protocol. Section 4 and 5 states development tools of SDN implementations, verification and debugging tools. In Section 6, we talk about several SDN applications in areas such as data centers and optical networking.
Literature Survey Of SDN:
SDN is undoubtedly one of the most promising concept which can change the way networks function, and particularly OpenFlow has been termed as a “radical new idea in networking” [1]. SDN is proposed to bring in changes ranging from centralized control, simplification of algorithms, network hardware commoditization, eliminating middle ware, to facilitating the design and deployment of third-party ‘apps’. Though OpenFlow received considerable industry attention recently only, the concept of programmable networks and decoupled control logic has been there for many years. Under this section, an overview of early programmable networking efforts, predecessors to the current SDN paradigm (that laid the foundation for most of the ideas we are seeing today), is provided.