A load adaptive mechanism for buffer management

International Journal of Information Technology, 2023

The quality of real-time network services is greatly dependent on the influential role of delay. This problem of high end-to-end delay is due in part to the presence of a congested network. Active queue management (AQM) algorithm accomplished at the router has since emerged as a robust area of research with a myriad of published works. One algorithm with a high hype in the research area is the random early detection (RED) proposed well over 2 decades ago. Previous enhancements to RED are unable to convincingly reduce the average queue size and improve network delay. To address these challenges that RED's one drop function is unable to meet, in this paper, wherefore, a new amendment to RED is described, namely modified dropping-RED (MD-RED). Contrastingly, in MD-RED, a linear drop function is tailored for light and moderate loads to establish a proportional growth in packet dropping while an exponential drop function is tailored for high traffic load to guarantee a more rapid increase in packet dropping. Reports from experiments conducted in ns-3 open-source simulation tool confirms that MD-RED suitably controls network congestion and offers an appreciable improvement in network delay.

IEEE/ACM Transactions on Networking, 1993

The authors present random early detection (RED) gateways for congestion avoidance in packet-switched networks. The gateway detects incipient congestion by computing the average queue size. The gateway could notify connections of congestion either by dropping packets arriving at the gateway or by setting a bit in packet headers. When the average queue size exceeds a present threshold, the gateway drops or marks each arriving packet with a certain probability, where the exact probability is a function of the average queue size. RED gateways keep the average queue size low while allowing occasional bursts of packets in the queue. During congestion, the probability that the gateway notifies a particular connection to reduce its window is roughly proportional to that connection's share of the bandwidth through the gateway. RED gateways are designed to accompany a transport-layer congestion control protocol such as TCP. The RED gateway has no bias against bursty traffic and avoids the global synchronization of many connections decreasing their window at the same time. Simulations of a TCP/IP network are used to illustrate the performance of RED gateways

-The Random Early Detection (RED) is used as an Active Queue Management (AQM) Technique for TCP congestion handling. A modification of RED called the Gentle RED (GRED) has been proposed by adding the Gentle parameter to the original implementation of RED. This parameter has been turned on by default in the NS2 simulator versions 2.1b and later; claiming that it helps in smoothing out traffic in routers and increases network performance. In this article we revisit this parameter and show, through simulation, that this parameter should be turned off in current simulations of RED using the NS2 simulator and it should be replaced by any adaptation parameter such as the Adaptive parameter in ARED.

Information Sciences, 2010

Wireless access points act as bridges between wireless and wired networks. Since the actually available bandwidth in wireless networks is much smaller than that in wired networks, there is a bandwidth disparity in channel capacity which makes the access point a significant network congestion point. The recently proposed active queue management (AQM) is an effective method used in wired network and wired-wireless network routers for congestion control, and to achieve a tradeoff between channel utilization and delay. The de facto standard, the random early detection (RED) AQM scheme, and most of its variants use average queue length as a congestion indicator to trigger packet dropping. In this paper, we propose a Novel autonomous Proportional and Differential RED algorithm, called NPD-RED, as an extension of RED. NPD-RED is based on a self-tuning feedback proportional and differential controller, which not only considers the instantaneous queue length at the current time point, but also takes into consideration the ratio of the current differential error signal to the buffer size. Furthermore, we give theoretical analysis of the system stability and give guidelines for the selection of feedback gains for the TCP/RED system to stabilize the instantaneous queue length at a desirable level. Extensive simulations have been conducted with ns2. The simulation results have demonstrated that the proposed NPD-RED algorithm outperforms the existing AQM schemes in terms of average queue length, average throughput, and stability.

This paper work presents simulation of an active queue management in a quality of service Internet using differentiated service random early detection (DiffServ RED) algorithm for congestion avoidance in packet switched network. RED algorithm is designed to accompany a transport­layer congestion control protocol such as TCP. We explored how the algorithm, earlier designed by [8], could be used to achieve differential packet dropping required by real­time traffic in the extended TCP/IP protocol for the Internet. The queue manager operates by setting thresholds (minimum and maximum) for the average queue size to detect incipient congestion. When the average queue size is below the minimum threshold, all arriving packets are properly enqueued for dispatch to their destinations. Any time the average queue size exceeds a preset minimum thresholds, the gateway drops packets at random or marks each arriving packet with a certain probability, where the exact probability is a function of the...

Journal of Computer Science, 2008

Congestion is an important issue which researchers focus on in the Transmission Control Protocol (TCP) network environment. To keep the stability of the whole network, congestion control algorithms have been extensively studied. Queue management method employed by the routers is one of the important issues in the congestion control study. Active Queue Management (AQM) has been proposed as a router-based mechanism for early detection of congestion inside the network. In this study, we are comparing AQM two popular queue management methods, Random Early Detection (RED) and droptail, in different aspects, such as throughput and fairness Index. The comparison results indicate RED performed slightly better with higher throughput and higher fairness Index than droptail. Simulation is done by using Network Simulator (NS 2) and the graphs are drawn using X-graph.

2012 IEEE Symposium on Computers and Communications (ISCC), 2012

The emergence of new kinds of applications and technologies (e.g., data-intensive applications, server virtualization) has led to a better utilization of the network resources. However, it has also led to more bandwidth consumption and more congestion especially inside data center networks. Thus, researchers are focusing again on TCP and Active Queue Management (AQM) mechanisms in order to better control congestion and to cope with application requirements in terms of end-to-end delay [1], [2], [3]. Recently, we proposed a new AQM mechanism (called α SNFAQM) that uses traffic prediction to accurately detect future congestion and to proactively act upon it [4]. In this paper, we develop an analytical model to assess the effect of α SNFAQM on TCP. The study proves that this AQM is efficient enough to stabilize queue size in routers/switches, and thereby allowing to control end-to-end packet delay. These results have been also validated by simulations for a topology with multiple bottleneck links. They show that α SNFAQM outperforms other AQM schemes like RED, PAQM and APACE in stabilizing instantaneous queue length, while keeping a high utilization of the links and the same packet loss rate.

In this paper, we propose a new mechanism called explicit rate notification (ERN) to be used in end-to-end communications. The ERN scheme encodes in the header of transmission control protocol (TCP) packets information about the sending rate and the round trip time (RTT) of the flows. This new available information to the intermediate nodes (routers) is used to improve fairness, increase utilization, decrease the number of drops, and minimize queueing delays. Thus, it induces a better management of the queue. A comparison of our scheme with preexistent schemes, like the explicit congestion notification scheme, shows the effectiveness of the proposed mechanism.

Active queue management (AQM) schemes have motivated many researchers to investigate more effective methods to control network congestion. Most AQM schemes are evaluated by their designers on the basis of router-centric metrics, such as queuing delay, link utilization and packet drop ratio. These metrics are important to network operators but they may not reflect the quality of service delivered to end-users. In this paper we propose a method aimed to provide users with better services in terms of end-to-end delay and packet loss ratio. The method captures a significant traffic increase at an early stage and signals TCP sources to slow down. In this way, TCP can quickly adjust the transmission rate, and thereby prevent overloading the network. In addition to RED, another two prominent AQM schemes, namely, random early marking (REM) and adaptive RED (ARED), are compared with the proposed method. Simulation results show that under various network loads and a range of network propagati...

Second IEEE International Symposium on Network Computing and Applications, 2003. NCA 2003., 2003

Active Queue Management (AQM) is intended to achieve high link utilization with a low queuing delay. Recent studies show that RED, one of the most well-known AQMs, is difficult to configure and does not provide significant performance gains given the complexity required for proper configuration. Recent variants of RED, such as Adaptive-RED are designed to provide more robust RED performance under a wider-range of traffic conditions but have not yet been evaluated. This paper presents a router queue behavior model (a queue law) for TCP-dropping and TCP-marking control systems, and uses the queue law to illustrate the impact of TCP traffic on the load and queue behavior of congested routers. Through queue law analysis and simulation, this paper confirms that RED-like AQM techniques that employ packet dropping do not significantly improve performance over that of drop-tail queue management. However, when AQM techniques use Explicit Congestion Notification (ECN) as a method to notify TCP sources of congestion rather than packet drops, the performance gains of AQM in terms of goodput and delay can be significant over that of drop-tail queue management.

IEEE Journal on Selected Areas in Communications, 1999

Recently, there has been much interest in using active queue management in routers in order to protect users from connections that are not very responsive to congestion notification. A recent Internet draft recommends schemes based on random early detection for achieving these goals, to the extent that it is possible, in a system without "per-flow" state. However, a "stateless" system with first-in/first-out (FIFO) queueing is very much handicapped in the degree to which flow isolation and fairness can be achieved. Starting with the observation that a "stateless" system is but one extreme in a spectrum of design choices and that per-flow queueing for a large number of flows is possible, we present active queue management mechanisms that are tailored to provide a high degree of isolation and fairness for TCP connections in a gigabit IP router using per-flow queueing. We show that IP flow state in a router can be bounded if the scheduling discipline used has finite memory, and we investigate the performance implications of different buffer management strategies in such a system. We show that merely using perflow scheduling is not sufficient to achieve effective isolation and fairness, and it must be combined with appropriate buffer management strategies.

International Journal of Distributed and Parallel systems

In IP networks, AQM attempts to provide high network utilization with low loss and low delay by regulating queues at bottleneck links. Many AQM algorithms have been proposed, most suffer from instability of queue, bursty packet drop, require careful configuration of control parameters, or slow response to dynamic traffic changes and unfairness. The deployment of active queue management techniques such as RED based is used that results in increased bursty packet loss and unfairness caused by an exponential increase in network traffic. The inherent problem with these queue management algorithms is that they all use queue lengths as the indicator of the severity of congestion. In order to solve this problem, a new active queue management algorithm called FAVQCHOKe is proposed. In this paper, arrival rate at the network link is maintained as a principal measure of congestion to improve the transient performances of the system and ensures the entire utilization of link capacity. In addition this proposed algorithm uses queue length and flow information that enhances fairness. This characteristic is particularly beneficial to real-time multimedia applications. Further, FAVQCHOKe achieves the above while maintaining high link utilization and low packet loss. This paper discusses about the inherent weaknesses of current techniques and how the proposed algorithm overcomes the weaknesses and ensures high degree of effectiveness in the performance of the system.

African Journal of Information & Communication Technology, 2008

The successful operation of the present Internet depends mainly upon TCP/IP which employs end-to-end congestion control mechanisms built in the end hosts. In order to further enhance this paradigm of end-to-end control the Random Early Detection algorithm (RED) has been proposed, which starts to mark or drop packets at the onset of congestion. The paper addresses issues related to the choice of queue length indication parameters for packet marking/dropping decisions in RED-type algorithms under varying traffic conditions. Two modifications to RED are proposed: (i) use of both instantaneous queue size and its Exponential Weighted Moving Average (EWMA) for packet marking/dropping and (ii) reducing the effect of the EWMA queue size value when the queue size is less than $min_{th}$ for a certain number of consecutive packet arrivals. The newly developed Hybrid RED algorithm can effectively improve the performance of TCP/IP based networks while working in a control loop formed by either ...

Proceedings of the 44th IEEE Conference on Decision and Control, 2005

The Internet is made of communication links and packet switching nodes named routers. Routers are equipped with buffers that hold packets during congestion and feed output links with packets during underutilization. A rule largely known in literature is the "bandwidth-delay rule", which states that, in order to guarantee full link utilization, it is necessary to provide each link with a buffer B = RT T • C, where RT T is the round trip time and C is the link capacity. The bandwidth delay rule requires buffer size that increases linearly with link capacity. With the recent introduction of 10 Gbps Routers and Ethernet cards, buffer requirements as dictated by the bandwidth-delay rule become extremely large. For instance, a 10Gbps router link with a RTT of 200ms would require a 2Gbits buffer size, which is a challenging requirement for manufacturers. Moreover, such a large buffers would introduce large and time-varying queuing delays that are harmful for time sensitivity traffic such as audio and video. In this paper we investigate the relation between the TCP congestion control and the buffer size required to guarantee full link utilization. We consider two TCP congestion control algorithms: the standard TCP NewReno and the recently proposed TCP Westwood+. Analytical results show that while classic TCP Reno/NewReno requires buffer of order size ∼ 1/ √ n, where n is the number of coexisting flows, Westwood+ TCP, in principle, can provide full link utilization for any buffer size. Discrete event simulations and experiment on real 10 Gigabit per second wide area network confirm theoretical results.

Comput. Sci., 2021

Considering the phenomenal growth of network systems, congestion remains a threat to the quality of the service provided in such systems; hence, research on congestion control is still relevant. The Internet research community regards active queue management (AQM) as an effective approach for addressing congestion in network systems. Most of the existing AQM schemes possess static drop patterns and lack a self-adaptation mechanism; as such they do not work well for networks where the traffic load fluctuates. This paper proposes a selfadaptive random early detection (SARED) scheme that smartly adapts its drop pattern based on a current network’s traffic load in order to maintain improved and stable performance. Under lightto moderate-load conditions, SARED operates in nonlinear modes in order to maximize utilization and throughput, while it switches to a linear mode in order to avoid forced drops and congestion under high-load conditions. Our conducted experiments revealed that SARED...