Parameter tuning of rate-based congestion control algorithm for ABR service class in ATM networks

A rate-based congestion control algorithm has been developed and standardized in the ATM forum for ABR service class. In the standard the behaviour of source and destination end systems is specified by several control parameters such as RIF (rate increase factor) and RDF (rate decrease factor). In spite of the fact that the performance of the rate-based congestion control algorithm depends heavily on the selection of these control parameters, no selection method of parameters is shown in the standard. In this paper, by extending our previous work, appropriate settings of rate-control parameters in the various circumstances are investigated. We first analyse the dynamical behaviour of the rate-based congestion control for multiple groups of ABR connections with different propagation delays. Next we evaluate the effect of CBR traffic on ABR connections. Simulation results for a multihop network configuration are also presented to exhibit the trade-off relationship among cell loss probability, link utilization and fairness. Finally, a selection method of control parameters in the multihop network is proposed based on our analytic methods and simulation results © 1998 John Wiley & Sons, Ltd.     

Characteristics of ABR explicit rate control algorithms in WAN environments and an ABR control algorithm suitable for public networks

This paper investigates the characteristics of available bit rate (ABR) explicit rate control algorithms in wide area network (WAN) environments. An ABR service is expected to make more effective bandwidth utilization possible through closed loop congestion control, and several control algorithms have been proposed. However, in WAN environments a long propagation control delay will affect the effectiveness of the control algorithms. Additionally, if a network supports a large number of connections, some of the algorithms may not work well. Thus we have categorized the control algorithms according to their purpose and mechanism and have evaluated their characteristics by simulation in WAN environments from the viewpoint of throughput, robustness, quickness, stability and fairness. Based on this analysis, we have developed an ABR control algorithm suitable for public networks. © 1998 John Wiley & Sons, Ltd.     

Evaluation of congestion control protocols for ABR traffic over ATM networks

Congestion control is very important for effective and stable operation of ATM (Asynchronous Transfer Mode) networks. Owing to the bursty and unpredictable characteristic of data network traffic, its congestion control is particularly a challenge for network researchers and designers. The ATM Forum has recently adopted rate‐based congestion control for ABR (Available Bit‐Rate) traffic which is the service class defined for data network applications. However, there is a number of congestion control schemes prevalent. ATM Forum has decided not to specify switch behaviour for ABR traffic; this has further introduced additional ambiguity. Consequently, an evaluation and comparison of the existing protocols would provide valuable guidance for network designers and engineers; it would also give insight for researchers to explore the essence of different congestion control schemes. In the first part of this paper, we investigate the effectiveness of ABR congestion control in the presence of bursty source traffic and the relationship between the burst time scale and the ABR control time scale. Two ABR congestion control schemes, the ABR Explicit Forward Congestion Indication (EFCI) and ABR Congestion Indication (CI) schemes, are compared with Unspecified Bit Rate (UBR) transport which makes no effort to control congestion. Traffic sources of various burst lengths of 100, 1000, 10000, and an equal mix of 100 and 10000 ATM cells are used in simulations. It is found that ABR congestion control schemes effectively control low frequency, medium to long‐term traffic load transients. This is further supported by the result of integrating TCP over ATM congestion control schemes included in the paper. ABR control schemes do not control high frequency, short‐term load transients well, but ABR control is not necessary in such cases since short‐term transients do not require a large amount of buffering. In the second part of this paper, we evaluate and compare six rate‐based congestion control protocols including Scheme I: EFCI, Scheme II: EFCI with separate RM queues, Scheme III: CI, Scheme IV: CI with separate RM queues, Scheme V: the CAPC2 ER (Explicit Rate), and Scheme VI: the EFCI with utilization‐based congestion indication. Each scheme is simulated and compared in the LAN, WAN, and GFC (General Fairness Configuration) environments specified by the ATM Forum. Effects of varying VC (Virtual Circuits) number and changing endsystem–switch distance has been investigated. Their fairness is also compared using the GFC configuration. We have found that ER control scheme performs significantly better than the other five binary control schemes by its faster response to congestion, smoother regulation of bit‐rates, lower queueing delay, shorter buffer queue length, and fairness. Among the other five schemes, the CI scheme performs better than the EFCI scheme. Providing separate RM queues has significantly improved the EFCI scheme in the WAN environment, but has little effect on the CI scheme. Link utilization‐based congestion detection has suffered from either low utilization or an excess cell loss which is unacceptable in most data applications. Copyright © 2000 John Wiley & Sons, Ltd.     

A novel core‐stateless ABR‐like congestion avoidance scheme in IP networks

We propose a novel explicit rate‐based congestion avoidance scheme. The scheme is similar to ATM available bit rate (ABR) services but its complexity is largely reduced to enable implementation in IP networks. In our proposed scheme, sources can adapt their sending rate according to network status. Adaptation of sending rates converges to max–min fairness with minimal rate guarantee. Furthermore, routers do not maintain per flow state; they use FIFO packet scheduling enhanced by an explicit rate feedback mechanism with estimations, including number of active flows, number of bounded flows and total bounded rate, based on a simple algorithm motivated by Bloom filter. We present and discuss simulations on the performance under various network conditions. Copyright © 2005 John Wiley & Sons, Ltd.     

携带虚拟队列长度信息的ABR业务流量控制算法

本文提出了一种新的基于速率检测拥塞的ABR流量控制算法--E-EFCI，它的基本思想是在基于速率检测拥塞的基础上扩展EFCI的功能，使其不仅反映网络阻塞状况，而且还反映网络排队状况。在交换机中通过虚拟队列的长度设置EFCI来传递网络的排队信息。仿真结果表明，本文提出的算法比基本EFCI算法具有更好的控制行为，减小了ACR和排队长度的振荡幅度，提高了链路、缓存利用率，加快拥塞解除，并具有较高的性能价格比。     

A new ABR congestion control algorithm achieving fairness under several criteria

All ABR congestion control algorithms reported are designed to achieve max-min fairness. In this paper, a new algorithm named dynamic bandwidth allocation algorithm is presented. Under the same framework, the algorithm can achieve fairness under several given criteria. Simulation result shows that the new algorithm works well under various network configurations, various traffic classes, and scale well to LANs or WANs.     

A congestion control framework for available bit rate service in ATM networks

Fair packet discarding (FPD) is a mechanism which provides incentives to users to co‐operate in congestion control, so that ATM networks can operate more efficiently. In this paper, we propose a simple congestion control framework consisting of a combination of FPD and ATM Forum's explicit‐rate flow control scheme. We show by simulations that this frame‐work achieves all objectives of congestion control: (1) control congestion, (2) achieve high user‐perceived throughput, (3) maintain fairness and (4) provide protection from misbehaving users. In addition, we equip this framework with two enhancements to improve efficiency, and reduce end‐to‐end delay. Copyright © 2002 John Wiley & Sons, Ltd.     

Adaptive message sending rate control method based on channel congestion cost calculation in VANET

In VANET,sending beacon messages reliably played a vital role in cooperative awareness and collision avoidance,and changes of vehicle density in real traffic environment had a direct impact on channel load and will cause the channel congestion to a certain degree,thus causing inefficiency of cooperative security applications.Aiming at this issue,a adaptive method based on channel congestion detection to control message sending rate was designed.First of all,an interference model that can accurately reflect the current state of the channel was established.Secondly,according to the Shannon information theory and network utility maximization theory,the optimal transmission speed of the current node in the physical layer was calculated.Finally,according to the mismatch of transmission rate and transmission queue length,the next moment's cost function of the channel congestion degree by monitoring the message queue was established to avoid channel congestion and queue overflow.The simulation experiment shows that the scheme effectively reduces communication transmission delay and avoids channel congestion,ensuring that the data be sent reliably.     

Feedback control of congestion in packet switching networks: the case of multiple congested nodes

In this paper, an analytical method for the design of a congestion control scheme in packet switching networks is presented. This scheme is particularly suitable for implementation in ATM switches, for the support of the available bit rate (ABR) service in ATM networks. The control architecture is rate-based with a local feedback controller associated with each switching node. The controller itself is a generalization of the standard proportional-plus-derivative controller, with the difference that extra higher-order derivative terms are involved to accommodate the delay present in high-speed networks. It is shown that, under the specific service discipline introduced here, there exists a set of control gains that result in asymptotic stability of the linearized network model. A method for calculating these gains is given. In addition, it is shown that the resulting steady state rate allocation possesses the so-called max-min fairness property. The theoretical results are illustrated by a simulation example, where it is shown that the controller designed, using the methods developed here, works well for both the service discipline introduced in this paper and for the standard FCFS scheme. © 1997 John Wiley & Sons, Ltd.     

ATM网络中ABR业务的流量控制

本文讨论了ＡＴＭ网络中ＡＢＲ业务的特性及基于ＡＢＲ业务的拥塞控制机制，了拥塞控制技术的最新发展情况，并比较了各种控制机制的优缺点。     

ATM网络基于EFCI机制的拥塞控制的缓存性能

本文根据文献「１」中给出的ＡＴＭ网络拥塞控制模型,对一类简单控制方案的缓存性能了深入的分析,得到了更为精确的缓存空间和阈值,同时讨论了多种业务在网络中共存的情况,并根据ＥＦＣＩ的拥塞检测机制,提出了一种新的控制策略。仿真结果表明了分析的正确性。     

一种参数自适应的ABR业务流量控制算法

在对二进制ABR流量控制算法建模的基础上，得出缓存队列长度与相关参数的关系。根据这种关系，经过比较分析，提出一种参数自适应算法，通过动态选择Nnm值，加快了网络对拥塞的响应速度。仿真表明，该算法在减轻振荡、快速解除拥塞以及减小对缓存的依赖方面有着良好的性能。     

Performance analysis of congestion avoidance algorithms with non‐zero MCR guarantee for ABR service in ATM networks

This paper proposes a novel explicit rate allocation algorithm called Fast Rate Allocation Congestion Avoidance (FRACA) algorithm supporting non‐zero minimum cell rate (MCR). The non‐zero MCR guarantee strategy for ABR service in ATM networks focused in this paper is MCR plus equal share (The ATM Forum Traffic Management Specification, version 4.0. April 1996). The main goals for designing the algorithm are the fast convergence according to the max–min fairness criteria, fairness among all sessions, maximum network utilization while the switch queue length is properly controlled. At the same time, it should work well under a wide range of network conditions without the need for adjusting the algorithm parameters. The performance of the proposed algorithm is evaluated and compared with the Generic Weighted Fairness (GWF) ERICA + (J Comput Comm 2000; 149). Simulation results show that the proposed algorithm achieves the design goals in the evaluated scenarios. Copyright © 2004 John Wiley & Sons, Ltd.     

无线多媒体网络中自适应拥塞控制算法的研究

提出了一种适用于采用无线接入多媒体流的拥塞控制算法,简称adaptive-MQWB(adaptivemediaQoSandwirelessbandwidth)。该算法依据当前带宽的动态变化率,在满足多媒体传输的最大时延的前提下,以最佳目标队长为实现目标,寻求最优的主动队列管理方案。仿真结果表明,与目前已有的MADR、tuned-RED算法相比,adaptive-MQWB算法在带宽动态变化的自适应性和多媒体传输时延的QoS保证方面都表现出更好的性能优势。     

按最小速率分配的ABR控制算法公平性的研究

现有和各种ＡＢＲ拥塞控制算法都只能实现最大最小准则下的公平分配。文中提出了一种称为“既得利益”相等的设计思想。依据这一思想改造现有算法,原则上可以在原算法框架内实现任一准则下的公平性。作为例子,我们改造了ＥＲＩＣＡ算法,使得新算法能达到ＡＴＭ论坛定义的按ＭＣＲ成比例分配带宽准则下的公平性。仿真实验结果表明,新算法性能良好。     

Adaptive load distribution approach based on congestion control scheme in ad-hoc networks

The ‘load distribution’ proposition in mobile ad-hoc networks (MANETs) is accomplishing great stimulation. This is because of the phenomenal facets it possesses including advanced network resilience, reliability and performance. Though there are other leading network layer routing protocols, but they radically utilise single-path communication paradigm, which is why they fail in achieving efficient load distribution in a network. Via this paper, we propose an efficient cross-layer adaptive load distribution approach to capitalise network’s channel utilisation and to rapidly adapt to dynamic wireless channel characteristic changes. The proposed method modifies the load balanced congestion adaptive routing (LBCAR) protocol and is developed using dynamic load distribution technique, by pioneering (i) novel parameters, which report for the availability of route pertaining to minimum traffic load and better link lifetime and also adapt according to varying available network resources; (ii) an absolute dynamic method to lessen the redundant route oscillations which further reduces the routing instabilities. The simulation results demonstrate the usefulness of the proposed method and yields better results in comparison to LBCAR and standard instead of dynamic ource outing, it is dynamic source routing (DSR) protocol.     

一种新型的ABR流量控制算法

提出了一种基于随动系统的ABR流量控制算法，该算法应用了跟踪系统的反馈机制，通过检验缓存中的队列长度来控制源端速率。理论证明，这种算法不仅提高了缓存的利用率，同时大大降低了信元丢失率，以及拥塞产生的可能。仿真结果表明，该算法在实际应用中也是可行的。     

TCP拥塞控制算法研究

随着各种网络应用的不断涌现,网络拥塞问题变得越来越严重,解决这一问题也就越来越重要。阐述了TCP拥塞控制的基本原理,然后介绍了现有的几种TCP拥塞控制算法,并对这些算法进行了分析比较,结果表明虽然每种算法都有其优点,但也存在不足,不能从根本上解决拥塞问题。文章最后指出了拥塞控制的问题所在以及解决方法的发展趋势。     

一类基于主动网络的网络拥塞控制策略

本文基于主动网络的思想,提出了在保持与传统拥塞控制策略兼容,而又不同于传统通用的“被动”式拥塞控制的“主动”式拥塞控制策略。我们以ＭＰＥＧ这一类在时间上短期和长期都相关的特殊数据流为例,进行了实验验证,其结果表明：我们所提出的主动拥塞解决很好地解决ＭＰＥＧ数据拥塞的问题。同时,也说明了用主动网络的思想来拓展目前的网络体系结构是可行的。     

Efficient congestion control mechanism for flow‐aware networks

Transmission based on flows becomes more and more popular in teleinformatics networks. To guarantee proper quality of service, to enable multipath transmissions, or just to increase transmission effectiveness in a network, traffic should be sent as flows. Flow‐aware networking architecture is one of the possible concepts to realize flow‐based transmissions. In this paper, the efficient congestion control mechanism (ECCM) is proposed to improve transmission in flow‐aware networks (FAN). The mechanism makes it possible to minimize acceptance delay of streaming flows (served with high priority) without deteriorating other transmissions in the network. It is confirmed by simulation experiments that the implementation of FAN with the ECCM mechanism is a promising solution for the Future Internet. Copyright © 2015 John Wiley & Sons, Ltd.