共查询到19条相似文献,搜索用时 796 毫秒
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虚拟网映射是网络虚拟化研究中亟待解决的问题,针对已有映射算法中存在的对于网络拓扑信息利用不足的现状,该文提出了基于资源区域聚集度的虚拟网映射算法(RCI-VNE)。在映射预处理阶段,根据局部拓扑信息和区域资源聚集度提出节点区域资源聚集评价算法。在节点映射阶段,提出一种基于节点区域资源聚集排名的2-近邻聚集映射算法,该算法将虚拟网节点集中映射到底层网络中可用资源丰富的区域,减小承载链路的长度。实验结果表明,该算法降低了虚拟网映射开销,且具有较高的虚拟网请求接受率和较低的平均执行时间。 相似文献
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在网络切片环境下,虚拟网络的资源分配是重要的研究内容.为降低底层网络的开销、提升虚拟网资源分配的成功率,本文提出了基于遗传算法的虚拟网资源分配算法.首先,本文对虚拟网资源分配问题进行建模,并设计了底层网络开销和底层收益两个评价指标.其次,为提升资源分配算法性能,设计了虚拟网节点资源需求规模的评价指标.最后,对遗传算法的关键要素进行定义,并提出了基于遗传算法的虚拟网资源分配算法.本文算法能够按照虚拟网的节点资源需求评估值确定资源分配的优先级,通过智能算法获得全局最优解.在实验部分,通过与传统算法比较,验证了本文算法降低了底层网络开销,提升了底层网络的收益和虚拟网络映射的成功率. 相似文献
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针对优化服务功能链(Service Function Chain,SFC)可靠性时资源利用率低的问题,提出了特征关联的服务功能链可靠性优化算法。首先,从底层节点的资源可用率、周边资源密集度、全网中心性评价其作为虚拟网络功能(Virtual Network Function,VNF)实例备选节点的优势,从VNF实例的节点度数与带宽流量评价其作为备选对象的优势。其次,逐个对优越性最高的VNF实例选择备份底层节点,直到所有SFC的可靠性满足客户要求。在为VNF实例选择备份底层节点时,提出了基于资源特征关联感知的备份节点选择算法,将当前VNF实例所映射的底层节点与其他待备份VNF实例的底层节点的邻接节点进行关联,为当前VNF实例选择最优备份底层节点的同时,减少为其他待备份VNF实例选择备份底层节点时链路的开销。仿真结果表明,相比于已有算法,该SFC可靠性优化算法下备份实例数降低了约29%,备份带宽资源消耗降低了约42%,SFC接受率提升了约12%。 相似文献
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解决虚拟网动态加入、离开导致的底层网络资源占用不均衡问题,提出基于预测的资源重配置算法(FRRA)。FRRA用已知信息预测资源重配置时间间隔,代替已有算法中周期性时间间隔。采取两方面措施保证重配置时机全局最优:将资源划分为关键资源和普通资源并使用不同配置算法;根据资源迁移失败概率,推导重配置请求次数极限值。与算法VNA-II、PMPA实验比较表明,FRRA的重配置花费比VNA-II节省69%,比PMPA节省42%;FRRA的虚拟网请求接收率比VNA-II提高29%,比PMPA提高52%。 相似文献
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底层物理节点或链路失效将影响虚拟网服务提供的连续性,因此如何实现虚拟网的可靠性映射是当前研究亟待解决的问题。文章建立了虚拟网映射(VNM)的数学模型,量化分析了虚拟网的可靠性,并归结出影响虚拟网可靠性的因素。为了克服这些因素,文章分别提出基于拓扑影响度(TID)的虚拟网映射(VNM-TID)算法和基于回溯机制的迁移算法(MA-Back)。仿真结果表明,VNM-TID MA-Back算法在虚拟网请求接受率、迁移成功率和有效承载率上具有优势,提高了虚拟网的可靠性。 相似文献
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该文对网络虚拟化技术中的虚拟网映射问题及其研究现状进行介绍,指出当前虚拟网映射算法在接入控制和算法性能评估方面存在的问题,提出一种支持接入控制的虚拟网映射近似算法,并给出了算法的竞争比分析。实验表明,该算法能提高物理网资源的负载均衡度和利用率,从而提高了虚拟网构建请求的接受率和物理网提供商的收益。 相似文献
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In order to solve the problem of virtual network mapping,a mapping method based on ant colony hybrid genetic algorithm was put forward under SDN environment,which established a linear programming model for virtual network mapping,and divided the mapping process into node mapping and link mapping.Firstly,the fusion algorithm was adopted,in which virtual nodes were mapped to physical nodes.Then the shortest path algorithm was used to map the virtual link to a physical link.On this basis,the acceptance ratio of virtual network requests can be improved.Simulation experiment results show that acceptance rate of virtual network requests can be increased by 10% efficiently using the ant colony hybrid genetic algorithm,compared with existing mapping algorithms D-ViNE,RW-BFS and R-ViNE.Further more,proposed method can greatly improve the average utilization rate of nodes and links and the ratio of the mapping income to cost. 相似文献
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网络虚拟化使得智能能量感知网络部署成为可能,已有研究忽略了节点映射能耗最优化。本文把节点映射能耗优化问题转化为生产地与销售地之间物资运输代价最优化问题,建立高效节能节点映射运输模型。根据最大元素法,提出了混合一阶段与两阶段映射算法,在链路映射的约束下找到节点分配最小能耗代价最优解;利用主动休眠策略,提出了基于运输模型的主动休眠虚拟网络映射节能算法;利用节点可重复映射技术,提出了基于运输模型的节点可重复映射算法,进一步提高了底层网络资源休眠数量。仿真结果验证了本文所提算法能够显著降低系统能耗,适合大规模高效节能虚拟网络映射。 相似文献
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在具有集中式控制特点的carrier-SDN(软件定义承载网)中应用网络虚拟化技术为虚拟网络分配资源,实现承载网资源分配是解决承载网结构僵化的重要途径。提出carrier-SDN中基于负载均衡的虚拟网络资源分配算法。首先,建立carrier-SDN多层模型;其次,根据虚拟网络映射算法的特点,二值化粒子群优化算法;最后,以负载均衡为优化目标,求解虚拟网络映射问题。仿真结果表明,与已有方法相比,所提算法在虚拟网络负载均衡性、请求接受率和网络收益方面性能优越。 相似文献
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Zhiguo Liu Lingyu Qin Qingli Liu Junmei Liu Yuanming Ding 《International Journal of Satellite Communications and Networking》2019,37(3):224-233
The virtual resource management architecture for satellite networks currently suffers from a very poor virtual network mapping success rate. This arises because of the need to map multiple heterogeneous virtual networks to the underlying satellite network. Most heuristic algorithms divide virtual network mapping into node mapping and link mapping, which aims to reduce the complexity of the problem. However, this approach is not well suited to highly dynamic satellite networks. In this paper, we propose a hybrid virtual network mapping algorithm that is based on threshold load. This takes the overall load for the nodes as its optimization objective, and combines the idea of backtracking contained in 1‐stage mapping methods and the idea of global optimization contained in 2‐stage mapping methods. The algorithm reduces the complexity of backtracking computation, while avoiding any incompleteness that might result from separating nodes and link mapping. The success rate for virtual network mapping is thus improved, as is the utilization rate for satellite network resources. 相似文献
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Zhongbao Zhang Xiang Cheng Sen Su Yiwen Wang Kai Shuang Yan Luo 《International Journal of Communication Systems》2013,26(8):1054-1073
Virtual network (VN) embedding is a major challenge in network virtualization. In this paper, we aim to increase the acceptance ratio of VNs and the revenue of infrastructure providers by optimizing VN embedding costs. We first establish two models for VN embedding: an integer linear programming model for a substrate network that does not support path splitting and a mixed integer programming model when path splitting is supported. Then we propose a unified enhanced particle swarm optimization‐based VN embedding algorithm, called VNE‐UEPSO, to solve these two models irrespective of the support for path splitting. In VNE‐UEPSO, the parameters and operations of the particles are well redefined according to the VN embedding context. To reduce the time complexity of the link mapping stage, we use shortest path algorithm for link mapping when path splitting is unsupported and propose greedy k‐shortest paths algorithm for the other case. Furthermore, a large to large and small to small preferred node mapping strategy is proposed to achieve better convergence and load balance of the substrate network. The simulation results show that our algorithm significantly outperforms previous approaches in terms of the VN acceptance ratio and long‐term average revenue. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Mohamed Haji Dahir Hadi Alizadeh Didem Gzüpek 《International Journal of Communication Systems》2019,32(6)
In this paper, we focus on energy efficient virtual network embedding in federated (multidomain) software‐defined networks (SDNs). We first formulate an optimization problem as an integer linear program (ILP) that minimizes the energy consumption of the network links, while at the same time adhering to the bandwidth and CPU requirements of the virtual network requests. We then propose a polynomial‐time heuristic algorithm, which consists of three stages. In the first stage, the top SDN controller decides on whether to partition the virtual network request into smaller subrequests and give subrequests to multiple domains or give the enitre virtual network request to a single domain, while in the second stage, each SDN controller implements virtual network embedding in its own domain. Finally, in the third stage, the algorithm performs interdomain routing if partitioning decision had been made in the first stage. Our simulation results demonstrate that our proposed algorithm yields close performance to the solutions obtained by using the optimization software CPLEX that implements our ILP. 相似文献