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This paper presents a study of Router based Congestion control approaches in wired network. As network is considered as a distributed system, any problem arises in such a system requires a distributed solution. Thus for good congestion control in the network we also need a solution distributed at source as well as router ends. The purpose of this study is to review the router based Congestion control research for wired network and characterize the different approaches to Congestion control design, by considering their advantages and limitations.

Abstract-Congestion control approaches, source based approach and router based approach have their own limitations. In source based approach, it is difficult to get correct location of congestion and without proper admission control; we cannot effectively manage the congestion problem. Thus both the approaches have to work in coordination for effective congestion control. In this context, an interaction study plays an important role to verify how a TCP implemented at source end works with Active Queue Management at router end. In this paper, we analyzed the performance of different high speed TCP variants at the source end with some recent AQM approaches: CoDel and sfqCoDel. The main objective of this work is to obtain the interaction patterns of different high speed TCP variants like: HTCP, Compound, HSTCP, Scalable and Cubic with recently proposed AQMs: CoDel and sfqCoDel. Simulation results show that that if we want to achieve a better throughput, minimum delay and improved fairness simultaneously, Cubic-sfqCoDel may be a good choice of TCP-AQM combinations for high speed networks.

Wireless Sensor Networks (WSNs) have earned an upsurging inquisitiveness of the research community over the past decade and for the upcoming era, due to which we can realize its countless applications in various fields including medical, military, environment and academia. Wireless sensor networks composed of thousands or sometimes millions of sensor nodes which are usually operated by batteries that have limited energy, data processing, storage and transmission capacity. Moreover, these sensor nodes are densely deployed in human inaccessible regions and connected through error prone wireless links to offer a long coverage, therefore It is very difficult rather impractical to analyze the behavior of WSNs with real experiments. Most researches in this particular field are carried out by using simulation tools in several educational associations and research hubs. For this reason study of existing experimental tools for analyzing the behavior of WSNs becomes essential. This paper is intended to present a review on experimental tools and techniques available in the literature for WSNs, including simulators, emulators and test beds. These tools are highly useful for analyzing the operational behavior of wireless sensor networks. This paper also provides a roadmap for selecting appropriate experimental tools for various kinds of WSNs and its applications by taking into account their capabilities, relative ease of use and accuracy.