网络虚拟化中的高效映射与流量管理研究

发布时间：2018-09-01 13:30

【摘要】：网络虚拟化是推动互联网体系结构创新的有效途径，其发展面临着虚拟网高效映射和物理网流量管理的双重挑战。一方面，虚拟网覆盖范围广，涉及物理网络自治域多，设计全局优化映射决策困难，数据中心虚拟网资源需求描述复杂，要求虚拟网映射机制不仅满足虚拟网的资源需求，还要提高物理资源的利用效率。另一方面，流量超线性增长，物理网络拥塞风险增大，网络不断扩容造成能耗持续攀升，要求流量管理机制不仅能够优化网络性能，还可以降低网络能耗。针对上述挑战，本文围绕提高虚拟网映射效率和增强物理网流量管理能力两大核心目标，分别从跨域虚拟网映射、数据中心虚拟资源分配、最优流量工程泛化路由框架、节能路由机制等4方面进行了研究和创新。本文的主要贡献包括： 1.设计了跨域虚拟网映射机制。针对映射过程中信息不对称的难题，本文提出了涉及多个物理网络域的有限信息共享机制，进而将映射问题建模为整数规划问题，并设计了可以在多项式时间求解的高效在线映射算法。实验表明，该算法的映射成功率和物理资源利用率均可达到理想情况下最优值的80% 90%。 2.设计了支持带宽保证的数据中心资源分配机制。针对数据中心虚拟资源需求描述难的现状，提出了任务资源需求解耦和的思路，设计了支持带宽保证的Dual Hose模型，以及与该模型相适应的虚拟机分配算法和带宽分配算法。实验表明，该机制的任务接受率比现有最佳方案提高了5.3%。 3.提出了实现最优流量工程的泛化路由框架。为了满足流量工程优化目标和实现方式的多样化需求，本文基于网络效用最大化理论提出了一种泛化路由框架和一类通用负载均衡效用函数，设计了实现最优路由的链路状态路由协议SPEF，并分析了基于MPLS的实现方式。实验表明，SPEF可将OSPF的网络效用提高10% 40%，基于MPLS的实现方式路径变化率仅为6.67%，路由稳定性好。 4.设计了高鲁棒性节能路由机制ROD。针对流量管理中性能、节能和鲁棒性互相制约的难题，ROD采用了分层组合优化的策略：首先建立以性能和节能为目标的联合优化模型，，得到满足特定约束的最优路由，然后优化该路由的鲁棒性，使其可以应对任意单链路故障的情形。实验表明，ROD可以按照流量管理需求，灵活地调整三个目标之间的关系，得到对应的路由结果。
[Abstract]:Network virtualization is an effective way to promote the innovation of Internet architecture. Its development is facing the dual challenges of virtual network efficient mapping and physical network traffic management. On the one hand, the virtual network covers a wide range, involves many autonomous domains of physical network, it is difficult to design global optimal mapping decision, and the data center virtual network resource requirement description is complex, which requires the virtual network mapping mechanism not only to meet the virtual network resource needs. It is also necessary to improve the efficiency of the utilization of physical resources. On the other hand, because of the super-linear growth of traffic, the increase of physical network congestion risk, and the continuous expansion of the network, energy consumption continues to rise, which requires that the traffic management mechanism can not only optimize the network performance, but also reduce the network energy consumption. Aiming at the above challenges, this paper focuses on the two core goals of improving the efficiency of virtual network mapping and enhancing the traffic management capability of physical networks, respectively from cross-domain virtual network mapping, data center virtual resource allocation, and optimal traffic engineering generalization routing framework. Energy-saving routing mechanism and other four aspects of research and innovation. The main contributions of this paper are as follows: 1. The mapping mechanism of cross-domain virtual network is designed. In order to solve the problem of information asymmetry in mapping process, a finite information sharing mechanism involving multiple physical network domains is proposed in this paper, and then the mapping problem is modeled as an integer programming problem. An efficient online mapping algorithm is designed, which can be solved in polynomial time. Experiments show that the mapping success rate and physical resource utilization rate of the algorithm can reach 80% 90% of the optimal value in ideal conditions. A data center resource allocation mechanism supporting bandwidth guarantee is designed. In view of the difficulty in describing the requirement of virtual resource in the data center, this paper proposes the idea of decoupling the resource requirement of the task, and designs the Dual Hose model which supports bandwidth guarantee, and the allocation algorithm of virtual machine and the bandwidth allocation algorithm which are suitable for the model. Experiments show that the task acceptance rate of the mechanism is 5.3. 3% higher than that of the best scheme available. A generalized routing framework for optimal traffic engineering is proposed. In order to meet the diverse requirements of traffic engineering optimization objectives and implementation methods, this paper proposes a generalized routing framework and a class of general load balancing utility functions based on the network utility maximization theory. A link state routing protocol (SPEF,) for optimal routing is designed and the implementation based on MPLS is analyzed. The experimental results show that the network utility of OSPF can be increased by 10% or 40%, the path change rate of the realization mode based on MPLS is only 6.67, and the route stability is good. 4. A robust energy-saving routing mechanism ROD. is designed. Aiming at the problem that performance, energy saving and robustness restrict each other in flow management, ROD adopts the strategy of hierarchical combinatorial optimization. Firstly, a joint optimization model is established to meet the specific constraints. Then the robustness of the route is optimized so that it can deal with any single link failure. Experiments show that ROD can flexibly adjust the relationship between the three objectives according to the requirements of traffic management and obtain the corresponding routing results.
【学位授予单位】：清华大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TP393.01

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