SDN网络中QoS控制技术研究与实现

发布时间：2018-04-15 04:33

本文选题：软件定义网络 + OpenFlow协议　；参考：《电子科技大学》2017年硕士论文

【摘要】：随着互联网的飞速发展,网络中业务种类日益增多,不同种类业务对服务质量(Quality of Service,QoS)的需求各不相同。然而,传统数据报网络对所有的业务都只提供尽力而为的服务。这使得在拥塞的情况下,网络很难保障不同业务的不同QoS需求。软件定义网络(Software Defined Network,SDN)作为一种新型网络,它解耦了传统网络中的控制层和转发层,使得控制层能获取全网拓扑视图并集中控制转发层的行为,为业务数据流提供灵活的QoS保证,这为QoS的研究提供了一个新思路。本文利用SDN网络可编程、易扩展以及有较强的网络管控能力等特点,研究SDN网络中的QoS控制技术,主要工作有:1)对四种不同种类业务进行了等级的区分,并设定不同等级值,在此基础上,提出了SDN网络中区分业务优先级的QoS控制框架,对最高优先级业务进行动态QoS路由,对其他等级业务进行以跳数为代价最短路径算法的路由,使用队列调度管理区分保障不同等级业务的QoS;2)以链路拥塞率、路径跳数为代价,路径时延为约束条件,对最高优先级业务使用拉格朗日松弛聚合代价(Lagrange Relaxation Based Aggregated Cost,LARAC)算法进行动态QoS路由,以保障最高优先级业务端到端的时延;3)提出了基于优先级队列(Priority Queue,PQ)调度算法、差额加权轮询(Deficit Weighted Round Robin,DWRR)队列调度算法和加权随机早期检测(Weighted Random Early Detection,WRED)队列管理算法的队列调度管理策略,进行不同优先级业务的区分调度管理;4)改进了OpenFlow协议,使得OpenFlow协议能支持队列命令,以对队列调度管理策略进行灵活配置。本文对QoS控制框架的拓扑管理模块、网络监测模块、路径计算模块、路由管理模块、队列代理模块和流量管理模块分别进行了实现,并在搭建的真实SDN网络中,对QoS控制框架进行了功能和性能测试。实验结果表明,QoS控制框架能对最高优先级业务进行动态QoS路由,较好地保证了最高优先级业务端到端的时延,并区分保障了不同等级业务的QoS,同时还提高了网络的吞吐量和带宽的利用率。
[Abstract]:With the rapid development of the Internet, the types of services in the network are increasing day by day. Different kinds of services require different quality of Service QoS (QoS).However, the traditional Datagram network provides only the best possible service for all services.This makes it difficult to secure different QoS requirements for different services under congested conditions.As a new type of network, Software Defined Network (SDN) decouples the control layer and the forwarding layer in the traditional network, enables the control layer to obtain the topology view of the whole network and centrally control the behavior of the forwarding layer, and provides flexible QoS guarantee for the service data flow.This provides a new idea for the study of QoS.This paper makes use of the characteristics of SDN network programmable, easy to expand and strong network control ability to study the QoS control technology in SDN network. The main work of this paper is to distinguish four kinds of different kinds of services, and to set up different grade values.On this basis, a QoS control framework is proposed to distinguish service priority in SDN network. Dynamic QoS routing is carried out for the highest priority services, and the shortest path algorithm at the cost of hops is used to route the other services at the cost of the number of hops.Queue scheduling management is used to distinguish the QoS of different classes of traffic at the cost of link congestion rate, number of path hops, and path delay.The Lagrange Relaxation Based Aggregated Code (LARAC) algorithm is used to route the highest priority services dynamically in order to guarantee the end-to-end delay of the highest priority services. A priority queue based scheduling algorithm is proposed.Difference weighted polling Weighted Round queue scheduling algorithm and weighted Random Early Detection (WREDR) queue management strategy, the differentiated scheduling management of different priority services (4) improves the OpenFlow protocol.The OpenFlow protocol can support queue commands to configure queue scheduling management policy flexibly.In this paper, the topology management module, network monitoring module, path calculation module, routing management module, queue agent module and traffic management module of QoS control framework are implemented, respectively, and are implemented in the real SDN network.The function and performance of QoS control framework are tested.The experimental results show that the QoS control framework can dynamically route the highest priority services and ensure the end-to-end delay of the highest priority services.The QoS of different levels of traffic is protected, and the throughput and bandwidth utilization of the network are improved.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP393.0

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