A Review of Router based Congestion Control Algorithms <s> II. RELATED WORKS <s> The authors propose a new taxonomy for congestion control algorithms in packet switching computer networks based on control theory. They view a network as a large, distributed control system, in which a congestion control scheme is a (distributed) control policy executable at each node (host or switches) of the network in order to a certain level of stable conditions. This taxonomy provides a coherent framework for the comparative study of existing algorithms and offers clues toward the development of new congestion control strategies. > <s> BIB001 </s> A Review of Router based Congestion Control Algorithms <s> II. RELATED WORKS <s> Selective packet dropping policies have been used to reduce congestion and transmission of traffic that would inevitably be retransmitted. For data applications using best-effort services, packet dropping policies (PDPs) are congestion management mechanisms implemented at each intermediate node that decide, reactively or proactively, to drop packets to reduce congestion and free up precious buffer space. While the primary goal of PDPs is to avoid or combat congestion, the individual PDP designs can significantly affect application throughput, network utilization, performance fairness, and synchronization problems with multiple transmission control protocol (TCP) connections. Scalability and simplicity are also important design issues. This article surveys the most important selective packet dropping policies that have been designed for best-effort traffic in ATM and IP networks, providing a comprehensive comparison between the different mechanisms. <s> BIB002 </s> A Review of Router based Congestion Control Algorithms <s> II. RELATED WORKS <s> Current end-to-end Internet congestion control under tail-drop (TD) queue management experiences performance degradations such as multiple packet losses, high queueing delay and low link utilization. In this paper, we review recently proposed active queue management (AQM) algorithms for supporting end-to-end transmission control protocol (TCP) congestion control. We focus recently developed control theoretic design and analysis method for the AQM based TCP congestion control dynamics. In this context, we analyze the problems of existing AQM proposals in which congestion is detected and controlled reactively based on current and/or past congestion. Then we argue that AQM based TCP congestion control should be adaptive to the dynamically changing traffic situation in order to detect, control and avoid the current and the incipient congestion proactively. Finally, we survey two adaptive and proactive AQM algorithms, PID-controller and Pro-Active Queue Management (PAQM), designed using classical proportional-integral---derivative (PID) feedback control to overcome the reactive congestion control dynamics of existing AQM algorithms. A comparative study of these AQM algorithms with existing AQM algorithms is given. A simulation study under a wide range of realistic traffic conditions suggests that PID-controller and PAQM outperform other AQM algorithms such as random early detection (RED) [Floyd and Jacobson, 18] and proportional-integral (PI) controller [Hollot et al., 24]. <s> BIB003 </s> A Review of Router based Congestion Control Algorithms <s> II. RELATED WORKS <s> Summary Congestion control mechanism is one of the key that keeps any network efficient and reliable for the users. Many mechanisms were proposed in the literature over theses years for the efficient control of congestion that occur in the network. Active Queue Management (AQM) is one such mechanism which provides better control in the recent years. It works at the router for controlling the number of packets in the router's buffer by actively discarding an arriving packet. Many schemes were proposed which give better delay performance and high throughput over different traffic conditions. In this paper an exhaustive survey is made on the AQM techniques that are proposed and the merits and short falls is presented <s> BIB004 </s> A Review of Router based Congestion Control Algorithms <s> II. RELATED WORKS <s> Since its formal introduction to IP networks in 1993 as a viable complementary approach for congestion control, there has been a steady stream of research output with respect to Active Queue Management (AQM). This survey attempts to travel the trajectory of AQM research from 1993 with the first algorithm, Random Early Detection (RED), to current work in 2011. In this survey we discuss the general attributes of AQM schemes, and the design approaches taken such as heuristic, control-theoretic and deterministic optimization. Of interest is the role of AQM in QoS provisioning particularly in the DiffServ context, as well as the role of AQM in the wireless domain. For each section, example algorithms from the research literature are presented. <s> BIB005
In Literature, the problem of Congestion has been studied widely in the context of high speed network, wireless network, satellite network, ad-hoc network etc. Substantial survey works have been reported regarding Congestion control. Some significant survey works related to the topic are as follows. Yang et al BIB001 (1997) have first proposed a taxonomy of Congestion control approaches in packet switched network, based on control theory. This taxonomy contributesa framework which helps in comparative study of the existing approaches and set a path toward the development of new congestion control approaches.Labrador et al BIB002 (1999)have given a comprehensive survey of selective packetdropping policies for the best-effort service of ATM and IP networks. They discussedthree router based congestion control schemes for IP networks, namely RED,RED In/Out (RIO) and Flow RED (FRED). They comparedRED and RIO in terms of fairness.Ryu et al  (2003) have presented a review of AQM algorithms for congestion control. They also done a survey of controltheoretic analysis anddesign of end-to-end congestion control with a router based scheme. As alternatives to AQM algorithms, they also surveyed architectural approaches such as modification of source or networkalgorithms, and economic approaches including pricing or optimization of allocatedresources.Chatranon et al  performance evaluationis performed to show the advantages and disadvantagesof only those schemes that don't require full per-flow stateinformation since they are more likely to be implemented inpractice.Ryu et al BIB003 (2004) have presenteda review of recently proposed active queue management (AQM) algorithms forsupporting end-to-end transmission controlprotocol (TCP) congestion control with a focus on recentlydevelopedcontroltheoretic design and analysis method for the AQM based TCP congestion control dynamics.Finally, theysurveyed two adaptive and proactiveAQM algorithms, PID-controller and ProActive Queue Management (PAQM), designed using classicalproportional-integral-derivative (PID) feedback control to overcome the reactive congestion control dynamicsof existing AQM algorithms. A comparative study of these AQM algorithms with existing AQMalgorithms is also given by them.An exhaustive survey is madeby Thiruchelvi et al BIB004 (2008) on the recent advances in the area of AQM techniques. Further they classified the AQM mechanismsaccording to the type of metrics they used as congestionmeasure. From the survey they found that the performancesof rate based AQM schemes are better than that of queuebased schemes and existing rate based schemessuch as AVQ,EAVQ may result in better performance interms of, throughput, packet loss, link utilization by the inclusion of more number ofcongestion measures.Chandra et al  (2010) have presented a brief survey of major congestion control approaches, categorization characteristics, elaborates the TCP-friendliness concept and then a stateof-the-art for the congestion control mechanisms designed fornetwork. They pointed out the major pros and cons of the various congestion control approaches and evaluated their characteristics.Adams BIB005 (2012)has done asurvey that attempts to travel the trajectory of AQM research from 1993 with the first algorithm, Random Early Detection(RED), to thework in 2011. In hersurvey she discussed the general attributes of AQM schemes, and the design approaches taken such as heuristic, control-theoretic and deterministic optimization.