To solve the traffic load imbalance issue in cellular networks, which is often in the form of hot-spots caused by the different user mobility levels, one of the good solutions at present is to construct heterogeneous ...To solve the traffic load imbalance issue in cellular networks, which is often in the form of hot-spots caused by the different user mobility levels, one of the good solutions at present is to construct heterogeneous integrated wireless networks that combine cellular networks and wireless local area networks （WLANs） together. In general, the traffic volume is significantly heavier in the hot-spots of cellular networks and a higher data transferring rate can be provided by introducing a WLAN so as to raise the utilization of the channel and achieve a good balance between user satisfaction and the efficiency of the network. In this paper, we provide a comprehensive performance comparison of the systems both before and after the integration, based on an existing mathematical model, focusing on both the qualitative and the quantitative analysis of changes in the performance of the system to validate the efficiency and superiority of the cellular/WLAN integrated systems over cellular-only systems.展开更多
数据中心网络流量分布的不均衡增加了网络拥塞产生的可能性,由于数据中心网络的流量特性,使得传统IP网络的流量工程方法不一定适合。该文在SDN/OF(software defined network/OpenFlow)的结构下,提出了一种基于多路径传输的动态路由算法(...数据中心网络流量分布的不均衡增加了网络拥塞产生的可能性,由于数据中心网络的流量特性,使得传统IP网络的流量工程方法不一定适合。该文在SDN/OF(software defined network/OpenFlow)的结构下,提出了一种基于多路径传输的动态路由算法(dynamic routing algorithm based on multipath propagation,Dramp)并作为SDN/OF结构中应用层的流量均衡策略。该算法在重新定义链路关键度并求解链路权值优化问题的基础上,能充分利用数据中心网络中存在的冗余路径,在完成细粒度流量均衡的同时,能很好地克服控制器的计算开销,完成路由优化的目标。通过在Mininet仿真平台中部署并进行仿真实验,与等开销多路径路由算法ECMP(equal-cost multi-path)以及GFF(global first fit)路由算法相比较,结果展示了Dramp的优越性能,同时证明了在数据中心网络中采用Dramp作为流量工程的解决方案更简单、更实用。展开更多
基于软件定义网络(software defined network,简称SDN)的数据中心流量工程,能够通过对全局视图的网络管控,动态选择路由路径,规避拥塞发生的风险.但是在制定路由策略时,经常会对数据流进行迁移,尤其是针对大流的迁移容易造成数据流丢包...基于软件定义网络(software defined network,简称SDN)的数据中心流量工程,能够通过对全局视图的网络管控,动态选择路由路径,规避拥塞发生的风险.但是在制定路由策略时,经常会对数据流进行迁移,尤其是针对大流的迁移容易造成数据流丢包以及接收端数据包乱序的问题.提出了基于时隙的流片装箱算法(flowlet-binned algorithm based on timeslot,简称FLAT),通过集中控制的方式获取链路状态信息并计算出合理的数据流传输时隙值,能够避免在数据流迁移过程中的丢包以及接收端数据包乱序问题;同时,在充分利用数据中心冗余链路的前提下,实现高效和细粒度的流量均衡.通过在Mininet仿真平台中部署并与ECMP以及GFF路由机制相比较,在链路高负载情况下,丢包率分别下降了90%和80%,而吞吐量分别能够提升44%和11%,实验结果展示了FLAT的优越性能.展开更多
文摘To solve the traffic load imbalance issue in cellular networks, which is often in the form of hot-spots caused by the different user mobility levels, one of the good solutions at present is to construct heterogeneous integrated wireless networks that combine cellular networks and wireless local area networks （WLANs） together. In general, the traffic volume is significantly heavier in the hot-spots of cellular networks and a higher data transferring rate can be provided by introducing a WLAN so as to raise the utilization of the channel and achieve a good balance between user satisfaction and the efficiency of the network. In this paper, we provide a comprehensive performance comparison of the systems both before and after the integration, based on an existing mathematical model, focusing on both the qualitative and the quantitative analysis of changes in the performance of the system to validate the efficiency and superiority of the cellular/WLAN integrated systems over cellular-only systems.
文摘数据中心网络流量分布的不均衡增加了网络拥塞产生的可能性,由于数据中心网络的流量特性,使得传统IP网络的流量工程方法不一定适合。该文在SDN/OF(software defined network/OpenFlow)的结构下,提出了一种基于多路径传输的动态路由算法(dynamic routing algorithm based on multipath propagation,Dramp)并作为SDN/OF结构中应用层的流量均衡策略。该算法在重新定义链路关键度并求解链路权值优化问题的基础上,能充分利用数据中心网络中存在的冗余路径,在完成细粒度流量均衡的同时,能很好地克服控制器的计算开销,完成路由优化的目标。通过在Mininet仿真平台中部署并进行仿真实验,与等开销多路径路由算法ECMP(equal-cost multi-path)以及GFF(global first fit)路由算法相比较,结果展示了Dramp的优越性能,同时证明了在数据中心网络中采用Dramp作为流量工程的解决方案更简单、更实用。
文摘基于软件定义网络(software defined network,简称SDN)的数据中心流量工程,能够通过对全局视图的网络管控,动态选择路由路径,规避拥塞发生的风险.但是在制定路由策略时,经常会对数据流进行迁移,尤其是针对大流的迁移容易造成数据流丢包以及接收端数据包乱序的问题.提出了基于时隙的流片装箱算法(flowlet-binned algorithm based on timeslot,简称FLAT),通过集中控制的方式获取链路状态信息并计算出合理的数据流传输时隙值,能够避免在数据流迁移过程中的丢包以及接收端数据包乱序问题;同时,在充分利用数据中心冗余链路的前提下,实现高效和细粒度的流量均衡.通过在Mininet仿真平台中部署并与ECMP以及GFF路由机制相比较,在链路高负载情况下,丢包率分别下降了90%和80%,而吞吐量分别能够提升44%和11%,实验结果展示了FLAT的优越性能.
