OSPF的流量工程扩展和CSPF路由算法研究

概要介绍了OSPF链路状态路由协议及其主要特点,同时描述了OSPF在带宽有限网络环境下的局限 性;针对OSPF的局限性,给出了MPLS流量工程的原理以及对OSPF的扩展要求。详细阐述了OSPF流量工程扩展 的方法以及CSPF的算法机制。最后结合工程实践,详细介绍了OSPF流量工程扩展和CSPF算法的实现。     

具有多维服务质量保证的OSPF实现技术

文中研究了一种具有多维服务质量保证的OSPF实现技术,通过优化OSPF的软件协议实现架构、增加扩展协议报文、基于路由算法进行适应性改造及软件内部元素结构扩展,使路由协议运行和计算路由表时可综合考虑链路的带宽、跳数、通信质量等要求,均衡网络流量并减小网络拥塞发生的可能性,使网络带宽资源利用率趋于最大化.理论分析证明,该技术最终满足通信最大限度的畅通与多维服务质量保证的综合要求.     

无线网络中基于DSDV的最大化吞吐量的协作路由算法

为最大化无线自组织网络的吞吐量,提出一种自适应的协作路由算法。在算法中,协作分集技术与路由选择相结合,通过在路由的每一跳选择最佳的中继节点协作发送节点传输信息来改善网络吞吐量。首先通过目的序列距离矢量路由协议（DSDV）初步建立最短路由路径,在每条链路的发送节点和接收节点根据邻节点表选出公共邻居节点,建立候选中继集合;进一步,每一跳根据链路吞吐量,在候选中继集合中自适应选择最多两个中继来协助发送节点进行传输,并根据选出的中继节点数动态分配节点发射功率。在保证系统发射功率一定的情况下,最大化网络吞吐量。仿真结果表明,在相同的发射功率下,相对于非协作路由DSDV算法,采用固定数量中继的协作路由算法提高了整个网络的吞吐量,而自适应的协作路由算法可进一步提高吞吐量;同时仿真了网络吞吐量与网络规模和节点最大移动速度的变化关系。      

集成IS-IS路由选择协议的研究

集成IS-IS是一种既可支持ISO无连接网络协议又可支持IP协议的域内网关路由选择协议。它与OSPF同属于链路状态路由选择协议,但更适合大型骨干网络,已经为许多运营商网络所采用。对集成IS-IS路由协议进行了分析,着重介绍了其工作原理,并与大家熟知的OSPF进行了对比,指出了集成IS-IS的特点。     

OSPF路由选择算法(Dijkstra)的理论与实现方法

导言数据网出现的历史并不长,但与其有关的技术却已经经历了多次的更新换代,其中域内选路协议更是如此。八十年代中期,RIP协议在大型、异构网络的环境下暴露出来的问题越来越多,迫切需要开发一种能够适应大型网络运营的可靠高效的域内选路协议。OSPF就是由IETF的IGP工作组为IP网开发的这样一种能适应大型网络需要的链路状态选路协议。如何高效快速的选路是每一种选路协议要解决的核心问题,本文将就OSPF的路由选择算法及其实现作深入的探讨。OSPF概述OSPF(开放式最短路径优先协议)是一种在自治域内部使用的、基于链路状的路由选…     

栅格化网络路由协议安全增强机制研究

文中研究栅格化网络广泛应用OSPF和BGP路由协议的安全性,分析路由协议的脆弱性与常规攻击手段,重点论证基于数字签名的OSPF、可信OSPF协议设计、BGP安全扩展、BGP报文保护等方案,以实现OSPF路由器发布公告与OSPF路由器间建立邻居关系的可靠性,有效解决BGP协议点到点通信链路的安全、地址起源认证、路由信息的完整性和真实性认证,为栅格化网络建设提供自主可控、安全可靠的路由协议。     

浅析OSPF动态路由协议

对目前在通信基础网络中广泛使用的OSPF动态路由协议进行分析,从路由表、动态路由协议、OSPF路由算法、OSPF网络规划等方面分别进行了阐述,为优化网络结构,提高网络管理水平打下基础。     

MPLS网络OSPF协议的实现与仿真

IETF的MPLS工作组.主要目标是开发一个综合选路和交换的标准,把路由选择功能转移到网络边缘,把效率更高、结构更简单的交换功能放在核心网络中.MPLS(多协议标签交换)技术是将第二层交换和第三层路由很好的结合起来的,以十分简洁的方式完成信息传递.路由协议有动态路由协议和静态路由协议之分,动态路由OSPF(Open Shortest Path First)协议允许将连续的网络和主机组合在一起形成一个集合,再加上有接口与这个集合中的任何一个路由相连的路由器形成了一个区域,这样有利于以后的大规模网络的仿真研究.本文中OSPF路由协议为MPLS提供了路由信息.     

基于时间序列分析的链路质量预测和稳定路由算法研究

针对现有链路质量预测算法不适用于实际通信场景的问题,该文提出一个不依赖于任何特定信号传输模型和节点移动模型、低复杂度的实时链路质量预测算法,并将其应用于稳定路由协议设计。通信节点存储并更新其邻节点的接收信号强度集合以构成时间序列,将时间序列分析中的局部线性核平滑方法和滑动窗口局部多项式预测方法引入链路质量判断及预测。在此基础上,结合跨层协作思想,提出了节点移动自适应的提前路由修复机制。仿真结果表明,该预测算法具有较高的预测准确度,并能显著增强路由稳定性,提高网络性能。     

针对MPLS网络流量工程的链路关键性路由算法

该文针对多协议标签交换(MPLS)网络流量工程提出了一种链路关键性路由算法(LCRA),该算法通过定义链路的平均期望负载来确定链路的关键性,进而映射为链路的权值来决定路由的选择。该算法的目的是使网络快捷地建立尽可能多的有带宽保证的路由,并且使这些路由均衡通过网络,实现网络负载均衡。与其他算法相比,该算法在路由拒绝率和重路由性能方面有很好的表现,并且路由的建立时间相当快捷。     

Energy-saving algorithm considering idle light-path prediction in SDM-EON

To effectively reduce the energy consumption,blocking rate and crosstalk between adjacent cores in a multi-core fiber for space division multiplexing elastic optical network (SDM-EON),an energy-saving algorithm considering idle light-path prediction was proposed.The extreme learning machine model was used to predict the traffic volume of each light-path in the network.Thus the idle light-path set and the maintenance time threshold of each idle light-path were obtained.Then,the actual maintenance time of the idle light-path was perceived by the prediction algorithm.Finally,in the light-paths where the actual maintenance time do not exceed the minimum maintenance time threshold and the inter-core crosstalk are lower than the crosstalk threshold,the idle light-path with the least loading energy consumption was selected to carry the new traffic.The simulation results show that compared with the traditional energy-saving algorithm,when the SDM-EON crosstalk limitation is satisfied,the proposed algorithm can lead better energy-saving while maintain the blocking rate at levels compatible.     

Integrating operation scheduling and binding for functional unit power-gating in high-level synthesis

Power-gating-aware design has been an active area of research in the last decade, aiming at reducing power dissipation while meeting a desired system throughput. In this study, an algorithm integrating both scheduling and binding processes is developed with the functional unit (FU) power-gating technique, to achieve maximum leakage energy reduction under both performance and resource constraints. Firstly, the possible leakage energy reductions of all idle intervals are analyzed by evaluating the operation mobilities. Secondly, a split network indicating the leakage energy reduction in each idle interval is constructed, and a min-cost flow-based algorithm is conducted to this network to evaluate the total leakage energy saving from power-gating FUs; operations are scheduled to the clock cycles and bound to FUs with a maximization of leakage energy saving. Finally, proper FUs are clustered under power domain constraints to maximize the leakage energy saving while reducing the area and wirelength penalties for fine grain power-gating. Experimental results show the effectiveness of our proposed algorithms in saving leakage energy.     

IP over WDM网络最小功耗模型和休眠机制研究

针对IP over WDM网络,建立了整数线性规划(ILP)最小功耗模型,计算了满足峰值业务需要开启的设备数目;对于低峰业务提出休眠机制,分别利用最小光路数算法与最小跳数算法,在保证连接无阻塞的情况下找出空闲设备,对比峰值业务得到不同算法下的设备使用率,确定IP over WDM网络的节能潜力。结果表明,ILP优化模型的网络功耗最小,最小光路数算法次之;低峰业务下利用休眠机制可以关闭设备的比例占40%～60%;采用最小光路数算法的休眠机制节能效果较优。     

嵌入式系统动态电源管理预测算法研究

针对目前在嵌入式系统中动态电源管理普遍采用超时算法节能效率低的缺点,采用预测的方法进行动态电源管理.提出一个动态电源管理预测算法,该算法通过利用设备空闲状态的历史信息对未来的空闲时间进行预测,预测结果作为动态电源管理的依据.实验结果说明该算法对工作状态平稳的系统空闲预测效果比较理想,适用于动态电源管理.     

基于网格分簇的无线传感器网络节能算法

无线传感器网络中,能量消耗问题一直最受人们关注.为了节省网络能量,针对现有算法存在的冗余节点过多以及能量利用率较低等问题,在以往算法的基础上,提出了一种基于网格分簇的节能算法,即基于网格分簇的无线传感器网络节能算法EABGC(Energy-saving Algorithm Based on Grid Clustering).该算法采用虚拟网格和贪婪算法等来节约网络能量.通过仿真实验,该算法与LEACH协议相比,能减少网络的能量消耗,从而达到节能的目的.EABGC算法,能有效地降低网络消耗,实现节能效果.     

无线自组传感器网络中基于能量的超宽带多路径路由算法

The Energy based Ultra-Wideband Multipath Routing (EUMR) algorithm for Ad hoc sensor network is proposed. It utilizes the function of UWB positioning to reduce the network communication delay and route overhead. Furthermore, the algorithm considers energy consumption, the residual energy and node hops of communication paths to make energy consumption more balanced and extend the network lifetime. Then routing which is stable, energy-saving and low-delay is realized. Simulation results show that the algorithm has better performance on saving energy, route overhead, stability and extending network lifetime.     

Method of network slicing deployment based on performance-aware

In order to deal with the performance degradation caused by resource contention due to the sharing of physical resources between VNF in the network slicing,a network slicing deployment method based on performance-awareness was proposed.When deploying network slice instances,first two-phase deployment that mapping virtual nodes was adopted,and then virtual links were mapped.In the virtual nodes mapping phase,the VNF performance influences factor was defined from the perspective of resource supply and demand to quantify the degree of VNF performance impact.Then the sum of the performance influence factors of all VNF on the deployable physical server was found in the network slice instance,the physical server with the smallest sum of performance influence factors was used as the mapping location,and the simulated annealing-discrete particle swarm algorithm was used to find the nodes mapping result.In the virtual links mapping phase,the shortest path algorithm was used to obtain the link mapping result.The simulation results show that the proposed method reduces the impact of other network slices on its own service performance.     

基于无色无向无冲突可重构光分插复用器节点的全光IP组播能效调度

为了提高无色无向无冲突灵活的可重构光分插复用器(CDC-F ROADM)节点的弹性光网络IP组播频谱-能耗效率,该文提出一种全光组播能效调度算法(AMEESA)。在算法路由阶段,考虑能耗和链路频谱资源使用情况设计链路代价函数,构建最小代价光树算法组播光树。在频谱分配阶段,设计基于高效光谱分辨率(HSR)光树中间节点频谱转换方法,选择节能频谱转换方案为组播光树分配频谱块资源。仿真分析表明,所提算法能有效提升网络能效,降低IP组播带宽阻塞率。     

IP over WDM网络中能耗自感知的混合疏导专有保护算法

针对绿色生存性IP over WDM网络中资源开销大、网络阻塞率高的问题,提出一种能耗自感知的混合疏导专有保护(HG-PA-DPP)算法。首先在IP层的核心路由器对低粒度业务请求集中疏导;然后通过实时感知WDM层的链路负载和双层器件带来的链路能耗状态定义链路权值,基于分层图在不同波长平面上为各业务请求寻找权值小且链路分离的工作路径和保护路径,同时在业务的中间节点处对不需要光-电-光转换的光路进行光旁路处理;最后,将空闲或保护资源设置为休眠模式以实现节能。仿真结果表明,所提算法在高负载时有着更好的节能效果,且在大网络拓扑下资源开销(RO)为传统算法的76.5%,阻塞率(BP)仅为传统算法的61.1%。     

Sleep mode operation for IEEE 802.16e UGS based WiMAX

To solve the problem of energy efficiency drop in wireless metropolitan area network communication due to frequently sleep-awake transitions, the energy-saving mechanism of the sleep mode operation was researched in WMAN. In this paper we propose a dynamic algorithm to tune the ratio of the sleep windows and receive windows according to the real time load. Then, a Markov chain model was set up to analyze the energy efficiency and mean access delay. NS2 simulation results show that the proposed algorithm can achieve marked gain in energy efficiency compared to the traditional energy saving mechanism.