 applications. This chapter focuses on the quality of service within the SDN network with its comparison and implementation using simulation. Types of quality of service is also discussed in this chapter with focusses on types of ways of implementation of quality of service. QoS management and orchestration architecture are also discussed here that allow us to manage the network in a modular manner. Performing our operation and results in such a network and shown the outputs for the same. The tenth chapter presents the security architecture of software defined network and different aspects related to security of software defined network. In this chapter, author discusses about Distributed denial-of-service (DDoS) which is a rapidly growing problem. The multitude and variety of both the attacks and the defense approaches is overwhelming. This chapter is a survey on the problem of denial- of-service (DoS) and Distributed Denial of Service (DDoS) attacks and proposed ways to deal with it. We describe the nature of the problem and look for its root causes, further presenting brief insights and suggested approaches for defending against DDoS. We point out both the positive and negative sides of each potential solution. Future work identifies and justifies open research issues. In conclusion, we give a brief summary of what has realistically been achieved SO far, as well as what are the key missing components. In this paper, we present a classification of available mechanisms that are proposed in literature on preventing Internet services from possible DDoS attacks and discuss the strengths and weaknesses of each mechanism. This provides better understanding of the problem and enables a security administrator to effectively equip his arsenal with proper prevention mechanisms for fighting against DDoS threat. The eleventh chapter discusses about WSN structure based on SDN. SDN based Wireless Sensor Networks (SDWSNs) consists of a set of software-defined sensor node equipped with different types of sensors. In SDWSN, sen