Exploring ControlMessage Quenching in SDNbased Management of 6LoWPANs This paper draws attention to techniques available for the minimization of control overhead in softwaredefined wireless sensor networks (SDWSNs). Softwaredefined networking (SDN) promises improved management flexibility and control for inherently resourceconstrained and heterogeneous wireless sensor network (WSN) implementations. However, due to the inband traffic channel available for data and control traffic in SDNbased WSNs, overhead control traffic has been viewed as a bottleneck affecting network performance and controller responsiveness. A discussion on the need for control message quenching (CMQ) and the various categories of CMQ implementations in SDWSN is made in this paper. Furthermore, a CMQ algorithm based on reducing duplicate flow request packets is discussed and demonstrated for implementation in an SDNbased WSN framework. Results show a significant reduction in control overhead traffic and noticeable improvement in energy efficiency. However, tradeoffs in terms of packet delivery rate and packet delay are also observed as a result of the CMQ algorithm. A discussion on future work necessary to optimize CMQ algorithms in order to minimize the associated tradeoffs is also made.

A comprehensive survey of interface protocols for software defined networks Abstract   Software Defined Network implementation has seen tremendous growth and deployment in different types of networks. Compared to traditional networks it decouples the control logic from network layer devices and centralizes it for efficient traffic forwarding and flow management across the domain. This multilayered architecture has data forwarding devices at the bottom in the data plane, which is programmed by controllers in the control plane. The highlevel management plane interacts with the control plane to program the whole network and enforce different policies. The interaction among these planes is done through interfaces that work as communicationprogramming protocols. In this survey, we present a comprehensive study of these interface and programming protocols, which are primarily classified into southbound, northbound, and eastwestbound interfaces. This work first classifies each of them into subcategories and then presents a comprehensive comparative analysis. As the different interfaces have different properties, hence, the subclassification and their analysis are done using different properties. In addition, we also discuss the impact of different virtualization techniques, such as hypervisors, on interface protocols and interplane communication. More over specialized interfaces for emerging technologies such as the Internet of Things and wireless sensor networks are also presented. Finally, the paper highlights several short term and long term research challenges and open issues specific to the SDN interface protocols.