【作者】 徐林磊；

【导师】 郑明春；

【作者基本信息】 山东师范大学 ， 管理科学与工程， 2011， 硕士

【摘要】 目前,互联网已经成为一个由大量网络自治域连接起来的异构的、巨型的复杂系统,随着高速网络,通信技术和流媒体技术的发展,出现了大量的各种新型应用,使传统的尽最大努力传递型的互联网服务体系设计遇到了严峻的挑战。随着网络规模越来越大,通信数据流穿越的异构自治域也越来越多,单纯依靠ISP之间的协作已经无法控制跨域的服务质量。为此,IETF开发了一系列提高Internet服务质量的RFC标准,但是,迄今为止,这些成果都没有大规模地实际应用于互联网,因此,在目前的Internet中尚没有有效的端到端的QoS保证。我们需要一种机制打破现在的域间互相独立、互相制约的局面,为此,学者们提出了一种实现端到端QoS服务的技术:服务覆盖网络(SON)。SON是由被称为服务网关(SG)的SON节点及虚拟链路构成。这些服务网关是由SON经营商统一部署的独立于底层AS的网络节点,这些节点具有数据转发和其他控制功能,它们之间通过虚拟链路建立起逻辑连接,虚拟链路是由底层IP网络提供的具有QoS保证的物理链路组成。由于SON节点与底层网络相分离,由SON经营商统一管理,屏蔽了底层网络的技术细节,也就解决了长期困扰我们的难以跨越异构网络向网络用户提供QoS的问题,同时也降低了管理和控制SON服务的复杂性,尤其是控制QoS的复杂性。SON路由是解决SON的关键问题,国内外学者对此提出了多种路由算法。本文首先介绍了服务覆盖网络相关的概念并对服务覆盖网络的路由研究现状进行了综述,对比分析了各种覆盖路由算法,然后综合分析Wardrop原理及其在通信网络中的应用,并在此基础上提出了两种SON中的Wardrop路由算法。本文提出的路由算法一方面满足了网络用户QoS的需求,提高了网络的服务质量;另一方面均衡网络负载提高了网络资源的利用率。因此提出的路由算法具有较高的理论价值和十分重要的现实意义。本文综合考虑了网络延时和带宽等多种影响网络性能的因素,通过对Wardrop原理UE模型的研究,从网络用户的角度出发,提出了基于UE模型的服务覆盖网络路由算法(UERSON)以达到提高网络服务质量的目的。在NS2的仿真环境中通过导入真实网络数据流验证了算法的可行性,对仿真实验结果的分析表明该算法的性能在一定程度上要优于已有的路由算法。但UERSON路由算法是一种自私路由算法而且该算法没有综合考虑SON经营商的收益,可能会影响SON经营商继续为网络用户提供优质的接入SON的服务。因此本文又在Wardrop原理SO模型的基础上提出了一种多下一跳路由算法(MNHRSON),该算法综合考虑SON经营商的利益和网络用户的服务需求,从网络全局作出路由选择。该算法的提出一方面保证了用户的QoS需求提高了网络的服务质量,另一方面最大化SON经营商的收益。在NS2的仿真环境中通过导入真实网络数据流验证了算法的可行性,对仿真实验结果的分析表明该算法的性能在一定程度上优于UERSON算法。更多还原

【Abstract】 Currently, the Internet has become a heterogeneous giant complex system connected by quantities of autonomous domains, with the development of high-speed networks and communication technologies and streaming media technology, a large variety of new applications has arisen; the traditional Internet service system design of trying best effort delivery type has encountered serious challenges. With the scale of networks increasing and the number of heterogeneous autonomous domains for communication data stream to cross increasing, relying on the collaboration among the ISP has not been able to control the quality of services across domains, for which, IETF Internet developed a series of the RFC standards to improve the quality of service, however, so far, these results have not been a large-scale practical application to the Internet, till now , Internet hasn’t had an effective guarantee of an end to end QoS. We need a mechanism to break the situation of current inter-domain independence of each other and checking each other, thus, scholars have put forward a technique which can achieve end to end QoS services: Service Overlay Network (SON). SON consists of what is called SON nodes of Service Gateway and virtual links. These service gateways deployed by the SON operator and independent of the underlying unified network are AS nodes of Internet, these nodes have data forwarding and other control functions, they establish a logical connection through a virtual link, virtual link consists of the QoS guarantee physical link provided by the underlying IP network. The separation of SON nodes and the underlying network as well as the unified management by the SON operator, mask the technical details of the underlying network, which solves the difficult long-term problems for our network users across heterogeneous networks to provide QoS, meanwhile reducing the complexity of the management and control the SON, especially the complexity of the control the QoS.SON routing is the key to SON. Domestic and foreign scholars have proposed a variety of routing algorithms. This paper introduces the relative concept of service network coverage and reviews the present study situation of service network coverage, comparative analysis of the various overlay routing algorithm, and comprehensive analysis of Wardrop Principle and its application in the communication network, and on this basis the two Wardrop routing algorithms in SON are put forward based on Wardrop principle. On the one hand, the proposed routing algorithms meet the QoS requirements of network users and improve the quality of network service; on the other hand, they balance the network load and improve network resource utilization. Therefore, the proposed routing algorithm has higher theoretical value and very important practical significance.This paper, considering the network delay and bandwidth and other factors that affect network performance, through the study of the principle of Wardrop and EU model, from the perspective of network users, puts forward the service overlay network routing algorithm (UERSON )based on UE model in order to achieve the purpose of improving the quality of network services. In NS2 simulated environment through the introduction of the real network data streams, the algorithm is proved feasible, the analysis of simulated experimental results shows that the performance of the algorithm is better than the existing routing algorithms to some extent. But UERSON routing algorithm is a selfish routing algorithm and the algorithm does not consider the benefits of SON operators, which may affect that the network operators continue to provide quality services to access to SON. Therefore this article puts forward a multi-hop routing algorithm (MNHRSON) based on SO model of the Wardrop principle, the algorithm considers the interests of SON operators and the network service needs of users, the network route is chosen from the global internet. On the one hand, the proposed algorithm guarantees the user’s QoS requirements and improves the quality of network service, on the other hand it maximizes the revenues of SON operators. In NS2 simulated environment through the introduction of the real network data streams, the algorithm is proved feasible, the analysis of simulated experimental results show that the performance of this algorithm is superior to UERSON algorithm to a certain extent.更多还原