SDN的ForCES实现及服务部署研究

发布时间：2018-04-16 00:28

本文选题：SDN + ForCES　；参考：《浙江大学》2014年博士论文

【摘要】：SDN是当前网络领域的研究热点,被业界认为是下一代互联网发展方向而备受关注。服务部署对SDN北向接口来说至关重要,而网络虚拟化更是SDN实现网络可编程的基础,它们一直来都是研究者重点关注的对象。现有的网络虚拟化研究,往往都是就虚拟化而虚拟化,并未过多考虑SDN的实际需求。目前为止,SDN的成功应用案例尚不多见,SDN中服务部署相关的研究更是少之又少。而ForCES作为可编程网络的典型代表,其转发与控制分离的思想与SDN一脉相承,且ForCES在模型控制和数据平面虚拟化等方面优势明显,因此本文结合可编程网络内有关服务部署的研究成果,将ForCES引入到SDN的研究。本文从服务部署和网络虚拟化的角度,提出一种基于ForCES的SDN新型体系架构,研究SDN下的服务部署和网络虚拟化,进而探索服务部署过程中的优化问题。基于上述分析,本文的主要研究内容如下： 1)分析比较现有SDN体系架构设计和实现的不足,结合ForCES在模型控制方面的优势,提出一种基于ForCES的新型SDN体系架构设计。 2)构建一个基于ForCES的网络虚拟化平台,提出一种ForCES-in-ForCES的网络虚拟化方法,并在网络虚拟化平台构建过程中,针对ForCES体系架构中的“FE瓶颈”问题,引入了一个专门用于转发平面接口和交换管理的组件SE,简化了网络虚拟化过程中的资源分配和管理。 3)研究SDN下的服务部署模型,针对服务部署的代价计算问题,提出了一种基于网络功能副本的部署代价优化算法,该优化算法通过为每个服务组件创建一个网络功能副本,基于网络功能副本选择虚边组合,计算可能的转移矩阵,从而排除了一些不必要的转移矩阵计算,降低了部署代价计算的复杂度。 4)针对服务请求,研究虚拟网中的路径发现,提出了一种“最小F(.)最短”的路径选评价方法,采用该方法进行路径选择,可以在同一个虚拟网中为更多的服务请求分配路径；设计了一种F(.)最小的路径查找算法,运行该算法可以确保所找到的路径总是非环且F(.)最小；针对虚拟网调整过程,提出了一种“优化方法”,该方法在不增加任何查询开销的情况下,扩张虚拟网,提供更多的可用路径,进一步提高服务请求的成功率。 5)研究节点查询过程的优化问题,针对查询过程中的每种查询方式提出一种基于策略的查询代价计算方法,该方法通过分析策略中节点的出现概率,评估该种查询方式下的查询代价;为降低整个查询过程的查询代价、减少查询过程中可行策略的数量,论文进而又提出一种策略枚举树的修剪算法,该算法通过去除策略枚举树上多余的等价子树和较差子树,减少了可行策略被执行的次数,降低了整个查询过程所带来的资源开销。
[Abstract]:SDN is a research hotspot in network field, which is regarded by the industry as the development direction of next generation Internet.Service deployment is very important to the northward interface of SDN, and network virtualization is the foundation of SDN to implement network programming, which has always been the focus of attention of researchers.The existing research of network virtualization is usually based on virtualization, without considering the actual demand of SDN.Up to now, the successful application cases of SDN are few and far from the research of service deployment in SDN.As a typical representative of programmable network, ForCES's idea of separation of forwarding and control is the same as SDN, and ForCES has obvious advantages in model control and data plane virtualization.Therefore, this paper introduces ForCES into the research of SDN based on the research results of service deployment in programmable network.From the point of view of service deployment and network virtualization, a new SDN architecture based on ForCES is proposed in this paper. The service deployment and network virtualization under SDN are studied, and the optimization problems in the process of service deployment are explored.Based on the above analysis, the main contents of this paper are as follows:1) analyzing and comparing the shortcomings of existing SDN architecture design and implementation, and combining the advantages of ForCES in model control, a new SDN architecture design based on ForCES is proposed.2) build a network virtualization platform based on ForCES, propose a network virtualization method of ForCES-in-ForCES, and in the process of constructing network virtualization platform, aim at the "FE bottleneck" problem in ForCES architecture.This paper introduces a special component SEE for forwarding flat interface and exchange management, which simplifies resource allocation and management in network virtualization.3) the service deployment model under SDN is studied, and a deployment cost optimization algorithm based on network function replica is proposed to solve the problem of service deployment cost calculation. This optimization algorithm creates a network function copy for each service component.The virtual edge combination is selected based on the replica of the network function, and the possible transfer matrix is calculated, thus eliminating some unnecessary transfer matrix calculations and reducing the complexity of the deployment cost calculation.4) for the service request, the path discovery in the virtual network is studied, and a kind of "minimum FN" is proposed.The shortest "path selection and evaluation method, which is used for path selection, can be used to assign paths for more service requests in the same virtual network.The smallest path lookup algorithm, which is run to ensure that the path found is always off-loop and FG.)Aiming at the adjustment process of virtual network, this paper proposes an "optimization method", which expands the virtual network without adding any query overhead, provides more available paths, and further improves the success rate of service requests.5) the optimization problem of node query process is studied, and a policy-based query cost calculation method is proposed for each query mode in the query process, which analyzes the occurrence probability of nodes in the strategy.In order to reduce the query cost of the whole query process and reduce the number of feasible strategies in the query process, a pruning algorithm of the strategy enumeration tree is proposed.By removing the redundant equivalent and inferior subtrees of the enumeration tree, the algorithm reduces the number of feasible strategies being executed, and reduces the resource overhead brought by the whole query process.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TP393.09

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