可重构网络的服务承载网映射技术研究

发布时间：2018-08-26 19:33

【摘要】：随着网络规模的日益扩大以及新型网络服务的不断涌现,采用固定不变的网络体系结构支撑需求多样化的网络服务将变得非常困难。为了解决以上问题,可重构网络在设计时借鉴了网络虚拟化的设计思想,也就是将网络基础设施提供和服务提供两大功能实体在逻辑上相分离,并通过构建服务承载网(Service Carrying Network, SCN)的方式为终端用户提供满足其需求的基础网络服务,而如何进行服务承载网的映射将对底层资源的利用效率将产生重要影响。本文依托国家重点基础研究发展计划(973)项目——“可重构信息通信基础网络体系研究”,结合项目对服务承载网构建技术方面的实际需求,重点研究了不同场景下的服务承载网映射技术,同时设计了映射所需的相关支撑机制。首先对映射所需要的资源监测框架和服务聚类算法进行了研究,然后针对单域集中式、单域分布式、跨域分布式这三种网络管理环境,分别提出了相应的服务承载网映射算法或策略,具体而言,本文的主要研究成果包括以下几点：1.为了使网络管理节点能够高效地生成服务承载网映射方案,需要一种实时的资源状态监测机制作为支撑。针对该需求,设计了一种网络资源监测框架,该框架通过设置监测代理来减少资源监测所需的通信开销。为了把监测系统的整体通信开销降到最低,首先将监测代理的部署问题转化为0-1规划问题,并利用改进的量子遗传算法进行求解,从而得到最优部署方案。此外,为减少拓扑的动态改变对监测系统稳定性的影响,设计了一种监测代理的动态调整策略。仿真实验表明,本文提出的策略不但无需管理员手动设置监测代理的数量,而且在降低通信开销方面优于其他同类型策略。2.为了给不同类型的网络服务构建相适应的服务承载网,需要按照QoS需求对网络服务进行聚类。在对服务聚类的功能需求和各种聚类算法的特性进行详细分析的基础上,选择了一种层次型聚类算法BIRCH作为服务聚类的解决方案。同时针对BIRCH算法存在的缺陷,提出了一种改进算法AS-BIRCH,该算法在处理任意形状簇这一问题上有着更好的适应性。最后通过实验验证了在网络服务聚类方面,AS-BIRCH算法的聚类准确率优于BIRCH。3.在可重构网络环境下,为了使传输质量优化的实际效果得到提升,在传统的映射原则之上提出了聚合映射原则,并基于该原则设计了一种面向聚合的服务承载网映射算法,该算法不但在请求接收率、负载均衡以及平均虚拟链路长度等传统的评价标准上有着较好的表现,而且能将类型相同的服务尽量映射到同一组底层节点和链路上,从而使更多的服务承载网能够受益于传输质量的优化。另外还通过虚拟节点和链路的迁移实现了一种服务承载网动态重构算法,该算法能够减少过载节点和拥塞链路的数量,并能有效提高服务聚合程度。4.在管理节点失效或是网络采用分布式管理模式的情况下,只能利用分布式映射算法进行服务承载网的映射,但已有的分布式算法存在通信开销大、虚拟链路映射代价过高的缺点。首先分析了集中式映射与分布式映射之间的差别,阐述了分布式映射的特点和应用场景。然后设计了一种基于协商的分布式服务承载网映射算法,该算法仅在小范围内进行状态信息的交换,从而减少了映射所需的通信开销,并且在缩短虚拟链路长度方面进行了优化设计。此外为了支持并行处理能力,算法还加入了冲突避免机制。实验证明,本算法只需要以较小的通信代价就能在各项指标上获得较好的评价。5.横跨多个底层网络域的映射能够为服务承载网提供更多的底层资源,但也在利益划分上带来了新的问题。为此,从满足网络运营商自私性的角度出发,提出一种面向收益最大化的服务承载网跨域映射策略,该策略通过竞价来实现跨域映射过程的控制,然后将本地映射问题转化为整数规划模型,并利用遗传进化的思想对其进行求解。实验表明该策略不但能提高运营商的收益,同时能够有效降低映射所需的开销。
[Abstract]:With the expansion of network scale and the emergence of new network services, it will be very difficult to support network services with diverse needs by using fixed network architecture. To solve the above problems, reconfigurable networks are designed with the idea of network virtualization, that is, to provide network infrastructure. The two functional entities of service delivery are logically separated from each other and provide basic network services to meet the needs of end users by constructing Service Carrying Network (SCN). How to map service delivery network will have an important impact on the utilization efficiency of underlying resources. Point-based Research and Development Program (973) project - "Research on Reconfigurable Informational Communication Foundation Network Architecture". Combining with the actual requirements of the project on the construction technology of service bearer network, this paper focuses on the mapping technology of service bearer network in different scenarios, and designs the supporting mechanism needed for mapping. Firstly, the mapping needs Resource monitoring framework and service clustering algorithm are studied. Then, for the three network management environments of single-domain centralized, single-domain distributed and cross-domain distributed, corresponding service bearer network mapping algorithms or strategies are proposed respectively. Specifically, the main research results of this paper include the following points: 1. In order to enable network management nodes to be able to. A real-time resource status monitoring mechanism is needed to efficiently generate service bearer network mapping schemes. To meet this requirement, a network resource monitoring framework is designed, which reduces the communication overhead of resource monitoring by setting up monitoring agents. The deployment problem of monitoring agents is transformed into a 0-1 programming problem and solved by an improved quantum genetic algorithm to obtain the optimal deployment scheme. In addition, a dynamic adjustment strategy of monitoring agents is designed to reduce the impact of dynamic topological changes on the stability of monitoring systems. Simulation results show that the proposed strategy is not only effective but also effective. There is no need for administrators to set up the number of monitoring agents manually, and it is superior to other similar strategies in reducing communication overhead. 2. In order to build a suitable service bearer network for different types of network services, network services need to be clustered according to QoS requirements. Based on the detailed analysis of the rows, a hierarchical clustering algorithm BIRCH is selected as the solution of service clustering. At the same time, an improved algorithm AS-BIRCH is proposed to overcome the shortcomings of BIRCH algorithm. The algorithm has better adaptability in dealing with the problem of arbitrary shape clusters. Finally, the experiment verifies the clustering of network services. As for clustering accuracy, AS-BIRCH algorithm is superior to BIRCH.3. In order to improve the actual effect of transmission quality optimization in reconfigurable network environment, the principle of aggregation mapping is proposed based on the traditional mapping principle, and an aggregation-oriented mapping algorithm for service bearer network is designed based on the principle. The algorithm not only requests connection, but also requests connection. Traditional evaluation criteria such as yield, load balancing and average virtual link length have better performance, and can map the same type of services to the same group of underlying nodes and links as far as possible, so that more bearer networks can benefit from the optimization of transmission quality. A dynamic reconfiguration algorithm of service bearer network is presented, which can reduce the number of overloaded nodes and congested links, and improve the degree of service aggregation effectively. 4. When the management node fails or the network adopts the distributed management mode, only the distributed mapping algorithm can be used to map the service bearer network, but the existing distribution. Firstly, the difference between centralized mapping and distributed mapping is analyzed, and the characteristics and application scenarios of distributed mapping are described. Then, a distributed service bearer network mapping algorithm based on negotiation is designed, which only carries out state information in a small range. In addition, in order to support the parallel processing ability, the algorithm also adds a conflict avoidance mechanism. Experiments show that the algorithm can get better evaluation on various indicators with less communication cost. 5. Mapping across multiple underlying network domains can provide more underlying resources for the service bearer network, but it also brings new problems in the division of benefits. To meet the selfishness of network operators, this paper proposes a cross-domain mapping strategy for service bearer network for maximizing revenue, which achieves cross-domain mapping through bidding. The local mapping problem is then transformed into an integer programming model and solved by genetic evolution. Experiments show that the strategy can not only improve the operator's profit, but also reduce the cost of mapping.
【学位授予单位】：解放军信息工程大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TP393.09

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