最小化路径代价和流量均衡模型及算法

流量均衡是流量工程中为避免网络拥塞经常采用的路由优化目标,如何选择路径以使流量达到均衡分布是流量路由的研究热点和难点.为了最小化网络拥塞,该文在指出网络拥塞决定于流量路由时所选路径的拥塞特征后,建立了流量分布的最小化路径代价和模型.在流量路由选择路径时,提出基于瓶颈链路的最小代价路径路由算法.在实际的网络拓扑和流量矩阵数据基础上对所提模型及算法进行了实验验证,结果显示:在网络负载较大时最大链路利用率相对于已有模型可降低近20%.     

基于最大流的无线mesh网络负载均衡信道分配算法

针对无线mesh网络中各信道间的干扰情况及流量负载均衡问题,定义了负载均衡的目标优化函数,设计一种基于最大流的负载均衡信道分配算法。该算法优先考虑为负载量比较大的链路分配更多的带宽,使得一些关键链路能够承受较大的流量负载,实现各信道的负载均衡,减少网络拥塞,降低分组丢失率和延迟。实验结果表明,该算法较好地平衡了网络负载,在网络业务较重的情况下还能获得较好的网络性能。     

基于价格调整和流量工程的软件定义数据中心网络传输优化方法

分析数据中心网络动态价格调整拥塞控制和流量工程传输优化方法的研究现状,提出结合拥塞控制、流量调度和负载均衡的网络传输优化方法,设计一种新型数据中心网络资源动态价格调整策略框架,构建一种两层结构的数据中心网络拥塞控制价格设置算法,平衡和调节各发送端的购买力和链路带宽收益之间的关系,根据各价格指标设计具有QoS路由技术与调度算法实现资源优化利用的流量工程方法,扩展OpenFlow协议算法,整合SDN、FAST协议、ECN三种技术,从运行机制方面找到提高数据中心网络传输性能的方法.     

智慧协同网络中基于流量矩阵的负载均衡路由机制

智慧协同网络具有能够实时准确测算流量矩阵的特点。将流量矩阵作为约束,对负载均衡路由优化问题进行建模,利用拉格朗日对偶方法,将原问题转化为优化目标易实现的对偶问题。为实现对偶问题优化目标,提出一种基于流量矩阵的负载均衡路由 (TM-LB,traffic matrix based load balancing) 算法,供控制层根据实时网络情况为后续流规划传输路径。利用OMNET++仿真器在NFSnet拓扑结构上进行仿真实验,结果表明TM-LB相比传统路径规划机制能有效避免拥塞,实现负载均衡。最后,搭建原型系统对TM-LB算法的开销进行测试。     

基于FPGA的流量负载均衡系统设计

介绍一种FPGA实现的流量负载均衡系统设计。该系统用于一路oc-192速率数据到四路oc-48速率数据的高速数据交换。设计基于区分服务,对有服务质量协议的数据固定队列交换，保证其QoS，并采用随机早期丢弃算法．提高对付网络拥塞的能力对无服务质量协议的数据采用灵活的最短队列交换，充分利用带宽。文中提出系统结构，给出存储单元管理方案,并且分析了结构的合理性，最后给出设计的硬件仿真结果。     

PRED:一种具有优先级自适应的队列管理新算法

现有的拥塞控制采用以TCP为核心的基于窗口技术的端到端控制,具有丢包、响应速度慢等缺陷.本文提出的基于优先级的队列管理算法(PRED),使路由器更加精确地管理队列,算法的主要参数能够适应网络负载的动态变化,有效地克服了现有拥塞控制的缺陷.实验结果表明,在相同的配置下,采用PRED的网络在降低丢包率、减少队列抖动等性能上均优于端到端拥塞控制.     

流量/拥塞控制技术研究

流量/拥塞控制的基本目的是以分布处理的方式有效地控制结点间的数据流,从而避免网络中出现拥塞。拥塞控制相应的控制策略称为拥塞控制算法(协议)。简述了Internet上基于TCP/IP的拥塞控制机制,分析和比较了TCP/IP上具体实现算法的稳定性,讨论了TCP/IP拥塞控制所面临的问题。     

基于分形点过程自相似流的队列性能分析

通过对交换机排队系统进行仿真,分析了以分形点过程( FPP )自相似业务流为输入的排队系统的性能.仿真结果显示,自相似业务流量模型下队列的性能与传统指数流量模型下的队列性能大不相同.文中所获得的仿真结果可用于网络流量模型、网络设计、网络拥塞控制和流量工程等.     

随机回退的TCP拥塞控制算法

 面对目前大量使用弃尾队列管理的网络中间节点,提出了一种随机回退的TCP拥塞控制算法TCP Njust,拥塞时在一定范围内随机减少拥塞窗口,拥塞避免时其拥塞窗口在一定范围内随机增加,以减缓TCP全局同步.该算法在Newreno基础上增加了一个随机函数,仿真表明该算法的性能优于Newreno,在网络突发数据流较多时,其性能优于Vegas,适合在Internet上使用.     

基于多信道协作负载均衡的WSN路由

在无线传感网络中,节点的资源限制给路由协议的设计提出了挑战。在高数据率应用场景中,带宽和存储容量成为其主要问题。为此,提出基于多信道协作负载均衡算法(M-CoLBA)的路由协议来提升网络带宽,并避免因队列溢出导致的数据包丢失。M-CoLBA协议先利用拥塞感知的动态路由度量均衡流量负载,再依据队列时延选择下一跳转发节点。实验数据表明,与单一信道路由协议(S-CoLBA)和多信道协议(M-HopCount)相比,提出的M-CoLBA协议具有较高的数据包传递率。     

基于SDN的互联网域间路由研究

互联网流量的爆发式增长,叠加互联网流量固有的突发性特点,使得网络流量不均衡现象日益加剧。传统BGP协议由于缺乏全网拓扑和全局流量观,只能遵循标准BGP选路原则,在解决流量调度和负载均衡方面存在不足。针对BGP协议存在的局限性,研发了基于RR+的互联网骨干网流量调度系统,并应用于ChinaNet骨干网的网内中继、网间互联出口、IDC出口等多个流量优化场景。更进一步地,提出了一种基于SDN的互联网域间路由架构,通过在域间控制器之间交换BGP路由,无需在域内和域间运行BGP协议,极大地简化了网络协议,并能够实现灵活的流量调度和负载均衡。     

Load Balancing for Parallel Forwarding

Workload distribution is critical to the performance of network processor based parallel forwarding systems. Scheduling schemes that operate at the packet level, e.g., round-robin, cannot preserve packet-ordering within individual TCP connections. Moreover, these schemes create duplicate information in processor caches and therefore are inefficient in resource utilization. Hashing operates at the flow level and is naturally able to maintain per-connection packet ordering; besides, it does not pollute caches. A pure hash-based system, however, cannot balance processor load in the face of highly skewed flow-size distributions in the Internet; usually, adaptive methods are needed. In this paper, based on measurements of Internet traffic, we examine the sources of load imbalance in hash-based scheduling schemes. We prove that under certain Zipf-like flow-size distributions, hashing alone is not able to balance workload. We introduce a new metric to quantify the effects of adaptive load balancing on overall forwarding performance. To achieve both load balancing and efficient system resource utilization, we propose a scheduling scheme that classifies Internet flows into two categories: the aggressive and the normal, and applies different scheduling policies to the two classes of flows. Compared with most state-of-the-art parallel forwarding schemes, our work exploits flow-level Internet traffic characteristics.     

粒度自适应的多径流量分割算法

针对多径传输存在的负载均衡和分组乱序之间的矛盾,提出了一种粒度自适应的多径流量分割算法。该算法在“流分片”的基础上,通过对流量特性的分析,将网络流量区分为正常流和强势流,基于“区分服务”的思想,不同流量分别采用适应其流量特性的流片分割粒度。理论分析和仿真结果表明,在考虑路径时延估计误差的情况下,该算法在降低分组乱序的同时具有良好的负载均衡性能。     

VoIP traffic in wireless mesh networks: a MOS‐based routing scheme

Support of Voice over Internet Protocol (VoIP) services in wireless mesh networks requires implementation of efficient policies to support low‐delay data delivery. Multipath routing is typically supported in wireless mesh networks at the network level to provide high fault tolerance and load balancing because links in the proximity of the wireless mesh gateways can be very stressed and overloaded, thus causing scarce performance. As a consequence of using multipath solutions, lower delay and higher throughput can be supported also when a given path is broken because of mobility or bad channel conditions, and alternative routes are available. This can be a relevant improvement especially when assuming that real‐time traffic, such as VoIP, travels into the network. In this paper, we address the problem of Quality of Service (QoS) support in wireless mesh networks and propose a multipath routing strategy that exploits the Mean Opinion Score (MOS) metric to select the most suitable paths for supporting VoIP applications and performing adaptive load balancing among the available paths to equalize network traffic. Performance results assess the effectiveness of the proposed approach when compared with other existing methodologies. Copyright © 2015 John Wiley & Sons, Ltd.     

Two phase load balanced routing using OSPF

The Internet traffic is growing, and its nature changes because of new applications. Multimedia applications require bandwidth reservations that were not needed initially when the file transfers dominated the Internet. P2P applications are making traffic patterns impossible to predict, and the traffic loads generated at nodes need to be routed regardless of the traffic pattern. When the guaranteed node traffic loads are known, bandwidth reservations can be made simple as will be explained in the paper. The shortest path routing (SPR) protocols used on the Internet today do not maximize the guaranteed node traffic loads, and do not provide scalable and fast bandwidth reservations. Load balancing can improve the network throughput for arbitrary traffic pattern. In this paper we analyze and implement a routing protocol that is based on load balancing and a commonly used shortest path routing protocol, and is, consequently, termed as LB-SPR. LB-SPR is optimized for an arbitrary traffic pattern, i.e. it does not assume a particular traffic matrix. Optimization assumes only the weights assigned to the network nodes according to their estimated demands. It will be shown that the optimized routing achieves the throughputs which are significantly higher than those provided by the currently used SPR protocols, such as OSPF or RIP. Importantly, LB-SPR calculates the guaranteed traffic loads and so allows fast autonomic bandwidth reservations which are the key for the successful support of triple-play applications, including video and audio applications that require high QoS. An actual modification of the TCP/IP stack that includes LBSPR is also described. Using the signaling mechanisms of the OSPF protocol, the information needed to perform the routing optimization is automatically distributed among the network nodes whenever the network topology changes. The LB-SPR implementation is validated on a sample network using a popular virtualization tool - Xen.     

Domain load balancing routing for multi-gateway wireless mesh networks

As Wireless Mesh Networks (WMNs) are typically used for Internet access, most traffic is routed through the gateways which connect WMN to the wired network. As a result, the gateways tend to get congested and balancing of the traffic load of gateways is critical. In this paper, we consider applications that require continuous provision of a certain bandwidth to a server located at the wired network. If a path that satisfies the bandwidth request cannot be found, the request will be rejected, so that load imbalance will result underutilization of the network capacity. We present a novel load balancing routing algorithm for maximizing the network utilization (i.e., accommodating service requests as many as possible) for multi-gateway WMNs. In the proposed scheme, a WMN is divided into domains. Each domain is served by one gateway, so that all traffic of a domain is served by the corresponding gateway. Our scheme determines routing to balance the traffic load among domains, and then performs load balancing routing within each domain. Simulation results show that in square grid topologies, our intra-domain routing achieves near optimal performance with about 70% less overhead than the existing schemes. Our inter-domain load balancing scheme outperforms the existing heuristics by up to 25% while achieving about 80% performance of the optimal solution.     

Flow-based load-balancing architecture for the agile all-photonic network

A novel routing architecture that balances incoming Internet flows over the agile all-photonic network (AAPN) is proposed. The architecture is based on the adaptive highest random weight (adaptive HRW) algorithm proposed to design load-balanced Internet routers. Extensive numerical evaluation of static and adaptive variations of the routing architecture is studied, and their effect on the network performance in terms of packet drop and flow remapping is presented. The architecture can be seen as a combination of adaptive core node scheduling and adaptive load balancing at the edge nodes. It is stateless and can compute routes quickly based on the packet flow identifier.     

一种支持业务均衡的OBS自适应多可达性路由机制

针对光突发交换(OBS)网络中如何高效解决频繁发生的光突发竞争问题,提出了一种支持业务均衡的OBS自适应多可达性路由机制(AMR-LB).首先根据发送端发送业务量大小和当前网络业务承载状态,按需地为光突发确定多可达性路由;然后在非线性规划下,自适应地调整各条路由的业务承载比例.通过性能仿真,并与自适应替代路由算法(AA...     

Research on scheduling method based on traffic matrix for IoT security

With the increasing number of sensors in the Internet of Things (IoT), network nodes are prone to load imbalance, which seriously affects the reliability and scalability of the IoT. In this paper, a method of load balancing is proposed to reduce the pressure of switches in IoT and improve the efficiency of switch. The method is based on software defined network (SDN) technology using dynamic traffic scheduling of server cluster (DTSSC) model. It obtains the traffic and load matrices for each server and achieves load balancing on each of them. This method has high efficiency and low overhead and is easy to deploy. The validity of this method is verified through experiments; ie, the load ratio of each server is balanced.