共查询到18条相似文献,搜索用时 140 毫秒
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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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针对现有的虚拟网络重构算法对物理网络中产生的碎片资源考虑不够周到,导致其对在线虚拟网络映射算法的性能改善不够显著的问题,该文定义了一种网络资源碎片度度量方法,并提出一种碎片感知的安全虚拟网络重构算法。该算法通过周期性考虑物理网络中节点的碎片度,选择出待迁移虚拟节点集合;通过综合考虑物理网络的碎片度减小量和虚拟网络的映射开销减少量,选择出最佳的虚拟节点迁移方案。仿真结果表明,该算法的请求接受率和收益开销比均优于当前的重构算法,特别是在收益开销比方面的优势更加明显。 相似文献
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虚拟网络映射是网络虚拟化的关键问题之一,其目的是在满足虚拟网络资源需求的前提下,为该虚拟网络分配合适的底层网络节点和链路资源,从而在共享的物理网络基础设施之上构建彼此隔离的多重异构虚拟网络,为网络基础创新研究提供实验环境和平台,为网络新应用提供承载服务。论述了虚拟网络映射模型和映射算法,并提出基于最小割集理论设计VN映射算法。 相似文献
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基于粒子群优化的负载均衡的虚拟网络映射 总被引:1,自引:0,他引:1
虚拟网络映射忽略通信路径上中间节点的资源消耗,以底层物理网络资源消耗最小或路径最短为目标,导致最优路径上中间节点资源不足而出现瓶颈,影响整个底层网络的性能及后续虚拟网络请求成功率。该文针对这一问题考虑物理路径上中间节点资源消耗,以节点负载和链路负载同时达到均衡为目标,将路径跳数限制作为约束,建立虚拟网络映射的数学模型,并采用多目标负载均衡粒子群优化算法求解,记作 LB-PSO。实验证明该算法有效地消除了资源瓶颈,为后续虚拟网络请求提供一个更为均衡的底层物理网络,从而提高了虚拟网络构建成功率、网络资源利用率以及基础设施提供商的收益。 相似文献
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网络虚拟化是解决网络僵化问题和更好地共享底层网络资源的一种有效途径,虚拟网络映射是实施网络虚拟化的关键问题之~。虚拟网络映射包括节点映射和链路映射两个方面,其目标是为虚拟网络请求分配合适的底层网络节点和链路资源。阐述了底层网络支持路径分割时,如何基于多商品流模型实现VN链路映射。 相似文献
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Network virtualization is a promising way to overcome the current ossification of the Intemet. It is essential challenge to find effective, efficient and robust embedding algorithms for recovering virtual network. The virtual network mapping algorithm based on integer programming which was proposed months ago. But it did consider the faults of physical network resources, which is so called survivable virtual network embedding (VNE) problem. Previous strategies for enabling survivability in network virtualization focused on providing protection for the physical network or enhancing the virtual networks by providing backup physical resources in advance, and treated all the physical failures as link failures. In the article, a dynamic recovery method is proposed to solve the survivable virtual network embedding problem based on the integer programming VNE algorithm. The dynamic recovery method doesn't need to backup physical resources and it makes more substrate resources which can be used in the embedding. The dynamic recovery process will be activated only when physical failures occur. Different algorithms are used to recovery node and link failures. Simulations show that the method helps to recover almost all of physical failures by finding the substitute nodes and paths, and its performance is very close to that of pure VNE method without considering physical failures. 相似文献
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Lü Bo HUANG Tao WANG Zhen-kai CHEN Jian-ya LIU Yun-jie LIU Jiang Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts Telecommunications Beijing China 《中国邮电高校学报(英文版)》2011,(5):87-94
Network virtualization is considered as a powerful way to deploy different network architectures and protocols over a shared physical infrastructure.Virtual network(VN)embedding plays an important role in the network virtualization environment.Virtual network embedding is mainly about mapping virtual nodes and virtual links onto the physical network resources efficiently.However,load balancing of substrate network has not received much consideration.This paper proposes an adaptive virtual network mapping algorithm based on status feedback.The main contribution is to embed the virtual network requests according to the current load distribution of substrate network.This adaptive algorithm differentiates the residual bandwidth of substrate links and takes full advantage of the multi-path to improve the load balancing of the substrate network.Simulation experiments show that the proposed algorithm improves the load distribution of substrate network distinctly while reducing the average substrate link stress significantly. 相似文献
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针对无线网络链路可靠性差影响无线虚拟网络的分配这一问题,提出了一种基于链路可靠性的无线虚拟网络分配算法(WVNEA-LR)。该算法通过物理网络拓扑预处理和允许同一个虚拟请求中的多个虚拟节点映射到同一个物理节点上的方法,提高了Vn构建成功率和节约了物理链路资源。利用Q因子改善了因拓扑分配稀疏时Vn构建成功率低的问题。此外,WVNEA-LR的节点分配为链路分配作了准备,并通过选择可靠性高的承载路径保证了分配后的Vn具有高可靠性。仿真结果表明, WVNEA-LR获得较好的虚拟网络构建成功率、较高的收益成本比和资源利用率。 相似文献
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The virtual network embedding/mapping problem is an important issue in network virtualization in Software-Defined Networking(SDN).It is mainly concerned with mapping virtual network requests,which could be a set of SDN flows,onto a shared substrate network automatically and efficiently.Previous researches mainly focus on developing heuristic algorithms for general topology virtual network.In practice however,the virtual network is usually generated with specific topology for specific purpose.Thus,it is a challenge to optimize the heuristic algorithms with these topology information.In order to deal with this problem,we propose a topology-cognitive algorithm framework,which is composed of a guiding principle for topology algorithm developing and a compound algorithm.The compound algorithm is composed of several subalgorithms,which are optimized for specific topologies.We develop star,tree,and ring topology algorithms as examples,other subalgorithms can be easily achieved following the same framework.The simulation results show that the topology-cognitive algorithm framework is effective in developing new topology algorithms,and the developed compound algorithm greatly enhances the performance of the Revenue/Cost(R/C) ratio and the Runtime than traditional heuristic algorithms for multi-topology virtual network embedding problem. 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