基于启发式多约束最优路径的软件定义网络服务质量路由算法研究

发布时间：2018-05-27 02:02

本文选题：软件定义网络 + 服务质量　；参考：《西安电子科技大学》2015年硕士论文

【摘要】：近年来,随着互联网的高速发展,互联网已逐步由单一的数据传送网向数据、图像和语音等多媒体信息的综合网演变,但现有互联网中的传输模型仍旧是单一的尽最大努力转发数据服务,故无法满足多媒体应用和各种用户对网络传输质量的不同要求。所以,为用户提供端到端的服务质量(Quality-of-Service,简称QoS)是一个极具活力的研究领域。传统网络架构下提供QoS的IntServ体系和DiffServ体系都面临着诸多问题,如IntServ体系需要数据通路上的每个路由器都参与路由决策,这就致使路由器负担太重,复杂度高;DiffServ体系下控制粒度过于粗放,导致端到端的控制效果不佳。因此,端到端的控制粒度与复杂度较低的集中控制就成了矛盾,这在传统网络架构中不可兼得。但在软件定义网络SDN(Software-Defined Networking)架构中,这一情况得以根本改变。和传统网络不同的是,SDN将网络中的控制平面和数据转发平面进行分离,使控制逻辑集中在了中央控制器,而普通的路由器只保留转发数据逻辑。因此在SDN中提供QoS是一种实现服务质量控制的高效率的方法,充分的应用了SDN的架构特点。然而,在SDN中,要实现跨越多个SDN网络的端到端QoS路由仍旧面临着巨大的挑战。为了解决跨越多个SDN网络的QoS路由问题,本文给出了一种基于多约束参数的QoS路由算法,同时,为了避免路径拥塞,给出了一种选择最优路径的启发式算法。并将该算法和其他几种路由算法做了对比实验。首先,对SDN网络的相关理论知识加以介绍,主要包括SDN概述、SDN体系架构以及SDN工作机制。随后介绍了几种经典的服务质量路由算法,包括多约束QoS路由算法、最优多约束QoS路由算法、探测法分布式路由算法、基于拉格朗日松弛算法、A*剪枝算法、遗传算法和蚁群算法。其次,针对SDN网络中域控制器只掌握本域的网络拓扑信息和转发器只有转发功能的特点,并且结合分布式路由策略和资源预留策略,给出了一种基于多约束参数的QoS路由算法。最后,本文基于SDN场景进行了仿真实验,并给出相应算法分析。使用测试数据进行了实验验证和对比。和其他两种QoS路由算法相比,我们提出的基于多约束参数的QoS路由算法能够大量减少网络中QoS请求包的数量,而获取的合理路径的数目只比利用洪泛法获取的合理路径数目少一小部分。
[Abstract]:In recent years, with the rapid development of the Internet, the Internet has gradually evolved from a single data transmission network to a comprehensive network of multimedia information, such as data, images and voice. However, the existing transmission model in the Internet is still a single best effort to forward data service, so it can not meet the different requirements of multimedia applications and various users on the network transmission quality. Therefore, providing end-to-end quality of service (QoS) for users is a very active research field. Under the traditional network architecture, both the IntServ system and the DiffServ system that provide QoS are faced with many problems. For example, the IntServ system requires every router in the data path to participate in the routing decision, which causes the router to bear too much burden. In the high complexity DiffServ system, the control granularity is too extensive, resulting in poor end-to-end control effect. Therefore, end-to-end control granularity and low complexity of centralized control become contradictory, which can not be used in traditional network architecture. But in the software defined network SDN(Software-Defined networking architecture, this has changed radically. Different from the traditional network, SDN separates the control plane from the data forwarding plane in the network, so that the control logic is centralized in the central controller, while the common router only retains the forwarding data logic. Therefore, providing QoS in SDN is an efficient method to realize QoS control, which fully applies the architecture characteristics of SDN. However, in SDN, end-to-end QoS routing across multiple SDN networks still faces great challenges. In order to solve the problem of QoS routing across multiple SDN networks, this paper presents a QoS routing algorithm based on multi-constraint parameters. In order to avoid path congestion, a heuristic algorithm is proposed to select the optimal path. The algorithm is compared with other routing algorithms. Firstly, the theoretical knowledge of SDN network is introduced, including an overview of SDN architecture and the working mechanism of SDN. Then, several classical QoS routing algorithms are introduced, including multi-constrained QoS routing algorithm, optimal multi-constrained QoS routing algorithm, detection distributed routing algorithm, Lagrangian relaxation algorithm and pruning algorithm. Genetic algorithm and ant colony algorithm. Secondly, a QoS routing algorithm based on multi-constraint parameters is proposed in view of the fact that the domain controller only knows the network topology information of the local domain and the repeater has only forwarding function in the SDN network, and combines the distributed routing strategy and the resource reservation strategy. Finally, the simulation experiment based on SDN scene is carried out, and the corresponding algorithm analysis is given. The test data are used to verify and compare the test data. Compared with the other two QoS routing algorithms, the proposed QoS routing algorithm based on multi-constraint parameters can greatly reduce the number of QoS request packets in the network. The number of reasonable paths obtained is only a small part less than that obtained by flooding method.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TP393.02

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