共查询到19条相似文献,搜索用时 515 毫秒
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IEEE802.17弹性分组环是宽带城域网的新型技术。凭着本地公平算法、空间重利用、带宽统计复用、正常状态双环均传输业务等特点从而和传统环网相比,弹性分组环在带宽利用方面具有较大的优势。公平算法对弹性分组环发挥其带宽利用优势具有极其重要的作用,而目前的基于节点公平算法不能完全发挥弹性分组环的优势。文章在更能发挥弹性分组环带宽利用优势的基于流的公平策略的基础上,建立相应的算法方案,并进行计算机仿真验证。实验结果验证了理论分析。 相似文献
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针对目前应用于弹性分组环(RPR)的公平算法存在的不足,文章提出了一种新的公平算法-HP—fa(High Performance—fairnessaigorithm),并对此算法进行了理论分析和仿真验证,结果表明该算法不仅带宽利用率高、收敛迅速,而且能够更好地实现环网的公平。 相似文献
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主要讨论弹性分组环网中的公平性算法,对现有的公平性算法进行了分类和比较研究,分析了其性能指标和技术特点,最后讨论它的发展趋势。 相似文献
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本文介绍了分组环网络,解释了它在城域网环境中的优越性,并且还提供了关于IEEE802.17 RPR标准的制定进展信息,IEEE 802.17 RPR工作组旨在开发弹性分组环的工业标准。 相似文献
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随着弹性分组环的广泛使用,公平有效地利用有限的带宽资源尤为重要。文章主要介绍了公平性算法的FPGA设计,使其具有现实意义。 相似文献
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The resilient packet ring (RPR) IEEE 802.17 standards is under development as a new high-speed technology for metropolitan backbone networks. A key performance objective of PRP is to simultaneously achieve high utilization, spatial reuse, and fairness, an objective not achieved by current technologies such as SONET and Gigabit Ethernet or legacy ring technologies, such as FDDI. The core technical challenge for RPR is the design of a fairness algorithm that dynamically throttles traffic to achieve these properties. The difficulty is in the distributed nature of the problem, that upstream ring nodes must inject traffic at a rate according to congestion and fairness criteria downstream. This article provides an overview of the RPR protocol with a focus on medium access and fairness. 相似文献
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翟德怀 《电信工程技术与标准化》2004,(9):60-63
在将RPR内嵌入MSTP并应用于城域环网时,公平算法(FA)无疑是最重要的RPR特性之一.本文首先介绍RPR公平算法的基本原理,并在此基础上,进一步分析了公平算法在不同层次城域环网应用中的公平使用带宽特性,及其对空间再利用特性的支持. 相似文献
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Resilient packet ring (RPR) standardized as IEEE 802.17 is a new medium access control (MAC) protocol for metro-ring networks. RPR supports spatial reuse which increases the achieved throughput but it can also result in congestion and starvation of nodes on the ring. Therefore, it is necessary to employ mechanisms to enforce a fair allocation of the ring bandwidth in RPR. In order to maintain fairness among nodes, a fairness algorithm is deployed at each RPR node. When a node detects congestion, it calculates a fair rate which is advertised to all upstream nodes contributing to congestion. Upon receiving the fair rate, the upstream nodes limit the rate of their injected traffic to the advertised fair rate. Consequently, the congested node can utilize the unused capacity and add its local traffic to the ring. In this paper, we develop an analytical model for fair rate calculation in the RPR aggressive mode fairness algorithm in the parking-lot scenario. This model provides an insight on dynamics of the RPR fairness algorithm and can be used to evaluate its performance. We investigate this problem in two cases. First, we assume that the link propagation delay is zero and derive the fair rate equations for this ideal case. We then consider the link propagation delay and develop a more realistic model. We verify the accuracy of our model by simulation results. Furthermore, we use the developed model to study the impact of various parameters on convergence of the fair rate. 相似文献
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弹性分组环中的公平算法浅析 总被引:6,自引:0,他引:6
弹性分组环(RPR,Resilient Packet Ring)作为下一代高速城域网的核心技术,具有高的带宽利用率、空间再利用和公平性等优良的特性。但要动态地获得这些特性,必须设计合理的带宽分配算法。文章指出了目前所采用的公平算法中存在的一些问题,探讨了一种更新的带宽分配算法;分布式虚拟时间调度(DVSR,Distributed Virtual-time Scheduling in Rings)算法。 相似文献
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首先讨论了RPR网络中的公平性原则,然后结合该原则引入了一种适合于RPR网络的公平分配方案,基于该方案提出了一种能满足RPR环网性能要求的公平分配算法。该算法通过采用控制的方法为共享某链路的各数据流合理地分配带宽资源,从而达到:(1)各流的速率达到稳定;(2)链路缓存的占有量稳定到一个目标值;(3)链路带宽得到充分利用且实现公平分配。同时该算法能顺次协同地处理完网络中的各个链路,从而能够实现整个RPR环网的公平性与高的链路带宽利用率,达到RPR协议所要求的目标。给出了该算法的代码描述并对其作出稳定性分析,然后通过仿真对其性能进行了验证。 相似文献
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The resilient packet ring (RPR) is a data optimized ring network, where one of the key issues is on load balancing for competing streams of elastic traffic. This paper suggests three efficient traffic loading algorithms on the RPR. For the algorithms, we evaluate their efficiency via analysis or simulation. 相似文献