End-to-end TCP (transmission control protocol) congestion control can cause unfairness among multiple TCP connections with different RTT (Round Trip Time). The throughput of TCP connection is inversely proportional to...End-to-end TCP (transmission control protocol) congestion control can cause unfairness among multiple TCP connections with different RTT (Round Trip Time). The throughput of TCP connection is inversely proportional to its RTT. To resolve this problem, researchers have proposed many methods. The existing proposals for RTT-aware conditioner work well when congestion level is low. However, they over-protect long RTT flows and starve short RTT flows when congestion level is high. Due to this reason, an improved method based on adaptive thought is proposed. According to the congestion level of networks, the mechanism can adaptively adjust the degree of the protection to long RTT flows. Extensive simulation experiments showed that the proposed mechanism can guarantee the bandwidth fairness of TCP flows effectively and outperforms the existing methods.展开更多
为了提高响应流和非响应流之间的公平性,提出了一种基于速率公平的RED改进算法——RF-RED(ratefairness random early detection).该算法在路由器端计算UDP流的平均速率并与TCP友好流速率进行比较,根据比较结果动态调整UDP流和TCP流的...为了提高响应流和非响应流之间的公平性,提出了一种基于速率公平的RED改进算法——RF-RED(ratefairness random early detection).该算法在路由器端计算UDP流的平均速率并与TCP友好流速率进行比较,根据比较结果动态调整UDP流和TCP流的最大丢包率,最后使用RED算法分别更新UDP流和TCP流的实际丢包率.通过使用RF-RED算法,UDP流在瓶颈链路上成为TCP友好流,同时瓶颈带宽得到了公平利用.仿真结果验证了该算法的有效性.展开更多
介绍了一种用于改善带宽公平性的随机优先检测新算法,即Bandwidth Fairness of RED(BF-RED)。该算法首先根据落差权重(drop-weight)定义了高带宽流,然后通过增加控制高带宽流的最大值和参数来增大落差的可能性。最后还在一些网络环境中...介绍了一种用于改善带宽公平性的随机优先检测新算法,即Bandwidth Fairness of RED(BF-RED)。该算法首先根据落差权重(drop-weight)定义了高带宽流,然后通过增加控制高带宽流的最大值和参数来增大落差的可能性。最后还在一些网络环境中模拟评估了该BF-RED算法。展开更多
Active Queue Management (AQM) is an active research area in the Internet community. Random Early Detection (RED) is a typical AQM algorithm, but it is known that it is difficult to configure its parameters and its ave...Active Queue Management (AQM) is an active research area in the Internet community. Random Early Detection (RED) is a typical AQM algorithm, but it is known that it is difficult to configure its parameters and its average queue length is closely related to the load level. This paper proposes an effective fuzzy congestion control algorithm based on fuzzy logic which uses the pre- dominance of fuzzy logic to deal with uncertain events. The main advantage of this new congestion control algorithm is that it discards the packet dropping mechanism of RED, and calculates packet loss according to a preconfigured fuzzy logic by using the queue length and the buffer usage ratio. Theo- retical analysis and Network Simulator (NS) simulation results show that the proposed algorithm achieves more throughput and more stable queue length than traditional schemes. It really improves a router's ability in network congestion control in IP network.展开更多
摘要:作为最著名的网络拥塞控制机制,随机早期检测(RandomEarly Detection,简称RED)算法由于其参数敏感性,无法在复杂多变的网络环境下保障良好的控制性能。为了改善RED敏感于参数的缺陷,增强算法的自适应性,文章将补偿模糊神经网络(com...摘要:作为最著名的网络拥塞控制机制,随机早期检测(RandomEarly Detection,简称RED)算法由于其参数敏感性,无法在复杂多变的网络环境下保障良好的控制性能。为了改善RED敏感于参数的缺陷,增强算法的自适应性,文章将补偿模糊神经网络(compensatory fuzzy neural network,简称CFNN)引入拥塞控制算法的设计中,结合RED和CFNN,得到了基于CFNN的RED变种算法(RED based on CFNN,简称CFNNRED)。与传统的RED相比,CFNNRED的改进在于:配置神经元一定的模糊逻辑规则,迅速得到丢包率,增强算法的可操作性和可实现性;通过神经网络的自学习,增强算法的自适应性和鲁棒性。最后通过仿真证明,CFNNRED算法的自适应性增强,对队列的控制能力得到加强,队列更加平稳,网络能够提供更加稳定的服务质量保障。展开更多
Improving the Quality of Service (QoS) of Internet traffic is widely recognized as a critical issue for the next-generation networks. In this paper, we present a new algorithm for the active queue management, namely R...Improving the Quality of Service (QoS) of Internet traffic is widely recognized as a critical issue for the next-generation networks. In this paper, we present a new algorithm for the active queue management, namely RED-DTB. This buffer control technique is used to enforce approximate fairness among a large number of concurrent Internet flows. Like RED (Random Early Detection) algorithm, the RED-DTB mechanism can be deployed to actively respond to the gateway congestion, keep the gateway in a healthy state, and protect the fragile flows from being stolen bandwidth by greedy ones. The algorithm is based on the so-called Dual Token Bucket (DTB) pattern. That is, on the one hand, every flow is rate-limited by its own token bucket, to ensure that it can not consume more than its fair share of bandwidth; On the other hand, to make some compensations to less aggressive flows, such as connections with larger round trip time or smaller sending window, and to gain a relatively higher system utilization coefficient, all flows, depending on their individual behavior, may have a chance to fetch tokens from the public token bucket when they run out of their own share of tokens. The algorithm is analyzed and evaluated by simulations, and is proved to be effective in protecting the gateway buffer and controlling the fair allocation of bandwidth among flows.展开更多
对多个著名的主动队列管理算法进行了深入的理论分析和实验比较,对它们的优点和不足进行了总结,并在此基础上提出了一种新的主动队列管理算法PFED(prediction-based fair early drop)·PFED的主要目标是:①通过对流量较为精确的预测...对多个著名的主动队列管理算法进行了深入的理论分析和实验比较,对它们的优点和不足进行了总结,并在此基础上提出了一种新的主动队列管理算法PFED(prediction-based fair early drop)·PFED的主要目标是:①通过对流量较为精确的预测,结合对分组丢弃概率更为合理的计算,将队列长度的变化稳定在一个理想的水平;②对非响应流实施有效的惩罚,提高算法的公平性;③通过合理的分组丢弃将队列(分组)的到达速率控制在链路的服务速率之下·仿真实验表明,PFED很好地实现了上述3个目标·展开更多
实用的传感器网络拥塞控制方案不仅需要满足多项网络性能指标,而且必须控制开销很小,提出了一种满足上述要求的拥塞控制机制EasiCC(EasiNet congestion control mechanism).在EasiCC中,数据流源节点将数据报文按比例划分到各优先等级中...实用的传感器网络拥塞控制方案不仅需要满足多项网络性能指标,而且必须控制开销很小,提出了一种满足上述要求的拥塞控制机制EasiCC(EasiNet congestion control mechanism).在EasiCC中,数据流源节点将数据报文按比例划分到各优先等级中,各网络节点根据网络拥塞程度动态地、同步地调整报文过滤标准,结合报文过滤标准和报文优先级来调节网络流量,保证了无线信道带宽分配上的公平性;将网络准入控制和队列丢包手段相结合来调整网络流量,保证了网络综合性能指标.EasiCC控制开销很少,已在实际传感器网络平台中实现.模拟验证和实验测试结果显示,EasiCC能够公平地为各数据流分配发报速度和网络带宽,并且在报文传输成功率、传输延迟等性能指标上均有良好的表现.展开更多
文摘End-to-end TCP (transmission control protocol) congestion control can cause unfairness among multiple TCP connections with different RTT (Round Trip Time). The throughput of TCP connection is inversely proportional to its RTT. To resolve this problem, researchers have proposed many methods. The existing proposals for RTT-aware conditioner work well when congestion level is low. However, they over-protect long RTT flows and starve short RTT flows when congestion level is high. Due to this reason, an improved method based on adaptive thought is proposed. According to the congestion level of networks, the mechanism can adaptively adjust the degree of the protection to long RTT flows. Extensive simulation experiments showed that the proposed mechanism can guarantee the bandwidth fairness of TCP flows effectively and outperforms the existing methods.
文摘为了提高响应流和非响应流之间的公平性,提出了一种基于速率公平的RED改进算法——RF-RED(ratefairness random early detection).该算法在路由器端计算UDP流的平均速率并与TCP友好流速率进行比较,根据比较结果动态调整UDP流和TCP流的最大丢包率,最后使用RED算法分别更新UDP流和TCP流的实际丢包率.通过使用RF-RED算法,UDP流在瓶颈链路上成为TCP友好流,同时瓶颈带宽得到了公平利用.仿真结果验证了该算法的有效性.
基金Supported by the National High Technology Research and Development of China (863 Program) (No.2003AA121560)the High Technology Research and Development Program of Jiangsu Province (No.BEG2003001).
文摘Active Queue Management (AQM) is an active research area in the Internet community. Random Early Detection (RED) is a typical AQM algorithm, but it is known that it is difficult to configure its parameters and its average queue length is closely related to the load level. This paper proposes an effective fuzzy congestion control algorithm based on fuzzy logic which uses the pre- dominance of fuzzy logic to deal with uncertain events. The main advantage of this new congestion control algorithm is that it discards the packet dropping mechanism of RED, and calculates packet loss according to a preconfigured fuzzy logic by using the queue length and the buffer usage ratio. Theo- retical analysis and Network Simulator (NS) simulation results show that the proposed algorithm achieves more throughput and more stable queue length than traditional schemes. It really improves a router's ability in network congestion control in IP network.
文摘摘要:作为最著名的网络拥塞控制机制,随机早期检测(RandomEarly Detection,简称RED)算法由于其参数敏感性,无法在复杂多变的网络环境下保障良好的控制性能。为了改善RED敏感于参数的缺陷,增强算法的自适应性,文章将补偿模糊神经网络(compensatory fuzzy neural network,简称CFNN)引入拥塞控制算法的设计中,结合RED和CFNN,得到了基于CFNN的RED变种算法(RED based on CFNN,简称CFNNRED)。与传统的RED相比,CFNNRED的改进在于:配置神经元一定的模糊逻辑规则,迅速得到丢包率,增强算法的可操作性和可实现性;通过神经网络的自学习,增强算法的自适应性和鲁棒性。最后通过仿真证明,CFNNRED算法的自适应性增强,对队列的控制能力得到加强,队列更加平稳,网络能够提供更加稳定的服务质量保障。
基金the National Natural Science Foundation of China(60132030)and the National Education Department Doctorial Foundation Project(RFDP1999048602)
文摘Improving the Quality of Service (QoS) of Internet traffic is widely recognized as a critical issue for the next-generation networks. In this paper, we present a new algorithm for the active queue management, namely RED-DTB. This buffer control technique is used to enforce approximate fairness among a large number of concurrent Internet flows. Like RED (Random Early Detection) algorithm, the RED-DTB mechanism can be deployed to actively respond to the gateway congestion, keep the gateway in a healthy state, and protect the fragile flows from being stolen bandwidth by greedy ones. The algorithm is based on the so-called Dual Token Bucket (DTB) pattern. That is, on the one hand, every flow is rate-limited by its own token bucket, to ensure that it can not consume more than its fair share of bandwidth; On the other hand, to make some compensations to less aggressive flows, such as connections with larger round trip time or smaller sending window, and to gain a relatively higher system utilization coefficient, all flows, depending on their individual behavior, may have a chance to fetch tokens from the public token bucket when they run out of their own share of tokens. The algorithm is analyzed and evaluated by simulations, and is proved to be effective in protecting the gateway buffer and controlling the fair allocation of bandwidth among flows.
文摘对多个著名的主动队列管理算法进行了深入的理论分析和实验比较,对它们的优点和不足进行了总结,并在此基础上提出了一种新的主动队列管理算法PFED(prediction-based fair early drop)·PFED的主要目标是:①通过对流量较为精确的预测,结合对分组丢弃概率更为合理的计算,将队列长度的变化稳定在一个理想的水平;②对非响应流实施有效的惩罚,提高算法的公平性;③通过合理的分组丢弃将队列(分组)的到达速率控制在链路的服务速率之下·仿真实验表明,PFED很好地实现了上述3个目标·
文摘实用的传感器网络拥塞控制方案不仅需要满足多项网络性能指标,而且必须控制开销很小,提出了一种满足上述要求的拥塞控制机制EasiCC(EasiNet congestion control mechanism).在EasiCC中,数据流源节点将数据报文按比例划分到各优先等级中,各网络节点根据网络拥塞程度动态地、同步地调整报文过滤标准,结合报文过滤标准和报文优先级来调节网络流量,保证了无线信道带宽分配上的公平性;将网络准入控制和队列丢包手段相结合来调整网络流量,保证了网络综合性能指标.EasiCC控制开销很少,已在实际传感器网络平台中实现.模拟验证和实验测试结果显示,EasiCC能够公平地为各数据流分配发报速度和网络带宽,并且在报文传输成功率、传输延迟等性能指标上均有良好的表现.
