基于SDN网络的负载均衡和流量工程技术的研究

发布时间：2018-01-06 07:12

本文关键词：基于SDN网络的负载均衡和流量工程技术的研究　出处：《安徽大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着计算机网络技术的不断发展,造成现有网络协议种类繁多、网络架构复杂且难以维护。流媒体、视频会议、云服务等新型网络业务的广泛应用,使得人们对网络服务质量要求越来越高,也使得如何提高网络综合性能来满足激增的网络应用和客户需求已成为时下热门的话题和关注的焦点。近几年,SDN网络的提出为网络创新研究提供了新的解决思路。这种新型的可编程网络体系架构可以从根本上解决一些已存在的网络问题,符合当今网络发展需求。SDN网络允许开发人员通过网络编程的方法控制网络流,通过一个控制器,实时地、全局地调控整个网络参数,同时可以监控网络设备的资源状态。当网络中出现状态变化的时候,底层网络设备会将情况变化通知给控制器,控制机会根据内设的算法进行计算出最优的结果,然后反馈到网络底层设备。底层设备会根据计算得到的流表信息对网络数据进行调度操作。SDN作为下一代网络研究创新平台,提高了网络整体的响应速度,显著提高了点到点的转发速度。OpenFlow是一种新型的将控制与转发分离的架构,是SDN网络的具体实例,OpenFlow控制器提供整体网络的控制和管理,OpenFlow交换机通过匹配流表负责数据转发。本论文概述了SDN的起源与发展,分析了OpenFlow协议标准,深入阐述了Floodlight控制器及Open vSwitch技术原理。本文针对SDN网络的需求,结合对传统网络的负载均衡和流量工程技术的研究,完成主要工作如下：首先,在SDN网络中,提出一种基于方差分析的负载均衡方法。针对现有传统负载均衡不能进行动态调整,对网络环境变化的感知能力差的问题,本文提出利用方差分析的方法对网络服务器端口流量进行监测,并通过概率选择的方法来动态地进行流量重定向控制。用户访问请求到达SDN网络的某个设备上,由SDN控制器根据网络运行状态,动态地将用户请求调度至合适的服务器,实现了服务器的负载均衡。该方法能够提供从接入、转发到服务的全方位容错,充分发挥服务器集群的总负载能力。通过实验表明该方法能有效地解决现有传统负载均衡可靠性不足,负载不均的缺点。其次,在SDN网络中,本文设计并实现了面向流量工程的约束分级模型。针对传统路由协议只是按照最短路径进行流量路由与转发,当最短路径流量已经满负荷时仍然将新的流量导入而不分流处理的问题,本文提出基于流量优先级的分级模型,当最短路径发生网络阻塞时,可以控制器会根据业务流量优先级进行分流处理,并分别对其架构和功能的实现进行了详细阐述。最后,通过构建的SDN网络仿真模拟环境进行实验,验证了模型的正确性及有效性。
[Abstract]:With the continuous development of computer network technology, there are many kinds of existing network protocols, the network architecture is complex and difficult to maintain. Streaming media, video conferencing, cloud services and other new network services are widely used. It makes people demand higher and higher quality of network service, and how to improve the comprehensive performance of the network to meet the surge of network applications and customer needs has become a hot topic and focus of attention in recent years. The SDN network provides a new solution for the research of network innovation. This new type of programmable network architecture can fundamentally solve some existing network problems. SDN network allows developers to control network flow through network programming, and to control the whole network parameters in real time and globally through a controller. At the same time, it can monitor the resource status of the network device. When the state changes in the network, the underlying network device will notify the controller of the change of the situation. The control opportunity calculates the optimal result according to the built-in algorithm. Then feedback to the network bottom device. The underlying device will schedule the network data according to the calculated flow table information. SDN will be used as the next generation network research innovation platform to improve the overall response speed of the network. OpenFlow is a new architecture that separates control from forwarding, and it is a concrete example of SDN network. The OpenFlow controller provides the control and management of the whole network. The OpenFlow switch is responsible for data forwarding through the matching flow table. This paper summarizes the origin and development of SDN. This paper analyzes the standard of OpenFlow protocol, expounds the Floodlight controller and the principle of Open vSwitch technology. This paper aims at the requirement of SDN network. Combined with the traditional network load balancing and traffic engineering technology, the main work is as follows: first, in the SDN network. This paper presents a load balancing method based on ANOVA, which aims at the problem that the traditional load balancing can not be dynamically adjusted and has poor perception of the change of network environment. In this paper, an analysis of variance (ANOVA) method is proposed to monitor the port traffic of the network server. Through the method of probability selection, the flow redirection control is carried out dynamically. The user access request reaches a device in the SDN network, and the SDN controller is based on the network running state. Dynamic scheduling of user requests to the appropriate server realizes the load balance of the server, and the method can provide an all-directional fault tolerance from access, forwarding to service. The experiments show that this method can effectively solve the shortcomings of the traditional load balancing reliability and load imbalance. Secondly, in the SDN network. This paper designs and implements a constraint hierarchy model for traffic engineering. The traditional routing protocol only performs traffic routing and forwarding according to the shortest path. When the shortest path traffic is already full load, the new traffic is still imported without shunt processing. In this paper, a hierarchical model based on traffic priority is proposed, when the shortest path is blocked. The controller can deal with the traffic flow according to the priority of traffic flow, and the implementation of its architecture and function are described in detail. Finally, the simulation environment of SDN network is constructed to carry out experiments. The correctness and validity of the model are verified.
【学位授予单位】：安徽大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TP393.06

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