基于ACK包对的带宽估计算法研究

发布时间：2018-04-10 10:46

本文选题：可用带宽测量　+ 数据包对技术　；参考：《厦门大学》2014年硕士论文

【摘要】：随着因特网的发展,网络管理和效率面临新的挑战。网络性能测量对协议的改进和网络服务质量的提高有重要意义。而网络带宽是关键的性能指标,在多种网络协议中起重要作用,例如网络拥塞控制、路由选择和媒体点播等。因此,带宽测量的算法研究一直是网络技术领域的研究热点。本文研究可用带宽的测量方法,目的是获取端对端路径上瓶颈链路的可用带宽。可用带宽测量技术可分为两种。(1)数据包对技术利用数据包对经过瓶颈链路产生的时间间隔来估计带宽,不足之处是对背景流量非常敏感。(2)分析探测数据包的发送速率和单向时延变化规律来估计带宽,不足之处是测量开销大,不适用于资源有限的网络环境。为了解决现有方法的不足,本文改进数据包对技术,并将其与TCP协议的确认机制(Acknowledgement,ACK)结合,设计和实现了基于ACK包对的带宽估计算法(ACK Packet Pair Probe,APROBE).APROBE通过改进时延样本的选择方案来计算带宽,有效降低背景流量对带宽测量准确性的影响；改造ACK机制,设计ACK包对以降低带宽测量的开销。APROBE算法己经在NS-3仿真平台中实现,并进行比较性验证：与Pathload相比,准确率相当；与Pathchirp相比,准确率提高了10%以上；测量开销则至少降低一个数量级。为了体现APROBE算法的可用性,本文将其成功应用于网络拥塞控制机制TCP Westwood,实现了新机制TCPWA。由于提高了网络带宽估计的准确性,TCPWA有效地提高了网络性能,例如网络吞吐量最多可增加37.5%。
[Abstract]:With the development of Internet, network management and efficiency are facing new challenges.The measurement of network performance is of great significance to the improvement of protocol and the improvement of network quality of service.Network bandwidth is a key performance index, which plays an important role in many network protocols, such as network congestion control, routing and media on demand.Therefore, the research of bandwidth measurement algorithm has been a hot topic in the field of network technology.In this paper, the available bandwidth measurement method is studied to obtain the available bandwidth of the bottleneck link on the end-to-end path.Available bandwidth measurement techniques can be divided into two types.) packet pair technology uses the time interval generated by the bottleneck link to estimate the bandwidth.The shortcoming is that it is very sensitive to the background traffic. (2) analyzing the law of transmitting rate and one-way delay of detecting data packet to estimate the bandwidth, the shortcoming is that the measurement cost is high, and it is not suitable for the network environment with limited resources.In order to solve the shortcomings of the existing methods, this paper improves the packet pair technology, and combines it with the confirmation mechanism of TCP protocol (Acacknowledgement-ACK).A bandwidth estimation algorithm based on ACK packet pair is designed and implemented to calculate bandwidth by improving the selection scheme of delay samples, which can effectively reduce the influence of background traffic on the accuracy of bandwidth measurement, and improve the ACK mechanism.The design of ACK packet pair to reduce the bandwidth measurement overhead. APROBE algorithm has been implemented in the NS-3 simulation platform, and compared with the Pathload, the accuracy rate is similar, compared with the Pathchirp, the accuracy rate is improved by more than 10%.The measurement overhead is reduced by at least one order of magnitude.In order to reflect the usability of APROBE algorithm, this paper successfully applies it to the network congestion control mechanism TCP Westwood, and implements a new mechanism TCPWA.TCPWA can effectively improve the network performance because of improving the accuracy of network bandwidth estimation. For example, the network throughput can be increased by up to 37.5%.
【学位授予单位】：厦门大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP393.06

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