基于OpenFlow的SDN组网技术研究

发布时间：2018-04-01 08:12

本文选题：SDN　切入点：OpenFlow　出处：《北京邮电大学》2014年硕士论文

【摘要】：随着网络互联技术的不断革新,传统的TCP/IP网络向着更加高速、开放、智能的方向发展,各种新的网络技术和协议不断出现。基于尽力而为的传输理念在承载新业务时面临了许多挑战,在扩展性,安全性,虚拟化,QoS等方面的问题层出不穷。研究者们开始着手设计一种新的构架来解决这些问题,软件定义网络SDN(Software-Defined Networking)由于其开放的网络构架,可编程性、集中控制、资源虚拟化等优势得到了学术界和企业界的广泛关注。单纯的SDN构架模型相对简单,如何有效的利用SDN的优势来实现业务需求是人们关注的焦点。本文面向未来网络的服务感知和数据感知的目标进行SDN组网技术研究。首先分析了SDN网络的构架,OpenFlow协议以及SDN网络设备的特点,并且调研了目前SDN在企业网,校园网,无线接入网,数据中心等方面的典型组网方案。SDN作为一种未来网络构架,对组网技术的研究既要考虑实现传统的网络业务需求,又要充分利用SDN的可编程特点考虑如何承载未来网络应用如信息为中心网络ICN(Information-Centric Network)业务。本文结合具体应用,讨论了两种组网应用模型。(1)针对现有组播网络的不可控和用户接入的任意性,提出基于SDN的安全组播组网模型,在该机制中不需要网络转发节点维护复杂的组播路由协议,由SDN控制器根据全局的拓扑来负责建立组播树,管理组播组,对用户的IGMP请求进行鉴权,设计了组播控制器并且基于开源的NOX编程实现。(2)分析了信息为中心网络(ICN)的关键技术,提出了基于SDN实现ICN的组网方案。ICN网络基于名字路由转发,而SDN基于流表匹配项中字段来转发数据包,本文中提出了ICN信息对象名字与OpenFlow标签的映射机制,为了更好的满足ICN对节点缓存和基于名字路由的需求,对现有的OpenFlow协议进行了扩展,包括增加缓存管理消息,流表的管理机制,最后提出了具备ICN功能的OpenFlow节点模型。 (3)搭建SDN实验平台,在实验平台上验证了基于SDN安全组播组网方案和基于SDN实现ICN组网方案的有效性。实验表明本文提出的组播机制,用户加入组播组时的需要鉴权,非法用户不能加入组播组。与传统IP组播相比,由于采用了集中式控制器计算组播树,具有更小的用户接入时延。基于SDN实现ICN方案中,和传统IP技术相比,由于在网络在进行了缓存,减小了源服务器的负载量,并且用户直接从距离较近的节点中获取内容,有更小的传输时延。文章的最后对全文所做的工作进行总结,并且对以后的工作进行了展望。
[Abstract]:With the continuous innovation of network interconnection technology, the traditional TCP/IP network is developing in the direction of higher speed, more open and more intelligent. A variety of new network technologies and protocols are emerging. Based on the best possible transmission concept, there are many challenges in carrying new services, such as scalability, security, There are many problems in virtualization, such as QoS. Researchers have begun to design a new framework to solve these problems. Software defines the network SDN(Software-Defined network, because of its open network architecture, programmability, centralized control, and so on. Resource virtualization and other advantages have been widely concerned by academia and the business community. The simple SDN architecture model is relatively simple, How to effectively utilize the advantages of SDN to realize business requirements is the focus of people's attention. This paper focuses on the research of SDN networking technology for future network service awareness and data awareness. Firstly, this paper analyzes the SDN network architecture and OpenFlow. Protocol and the characteristics of SDN network devices, As a kind of future network framework, the typical networking scheme of SDN in enterprise network, campus network, wireless access network, data center and so on is investigated. The research on networking technology should take into account the need of realizing traditional network service. It is also necessary to make full use of the programmable characteristics of SDN to consider how to carry future network applications such as information-centric network ICN(Information-Centric network. This paper discusses two networking application models. (1) aiming at the uncontrollable multicast network and the arbitrariness of user access, a secure multicast network model based on SDN is proposed, in which the network forwarding nodes are not required to maintain complex multicast routing protocols. According to the global topology, the SDN controller is responsible for establishing multicast tree, managing multicast group, authenticating the user's IGMP request, designing the multicast controller and implementing NOX programming based on open source. In this paper, we propose a network scheme based on SDN to implement ICN. ICN network is based on name routing, while SDN forwards data packets based on the fields in stream table matching items. In this paper, a mapping mechanism between ICN information object name and OpenFlow tag is proposed. In order to better meet the requirements of ICN for node caching and name-based routing, the existing OpenFlow protocols are extended, including the addition of cache management messages, the management mechanism of flow tables, and the proposed OpenFlow node model with ICN function. The SDN experimental platform is built to verify the validity of secure multicast network scheme based on SDN and ICN network scheme based on SDN. The experiment shows that the multicast mechanism proposed in this paper needs to be authenticated when users join multicast group. Illegal users can not join multicast group. Compared with traditional IP multicast, the centralized controller is used to calculate multicast tree, which has smaller user access delay. In ICN scheme based on SDN, it is compared with traditional IP technology. Because of the cache in the network, the load of the source server is reduced, and the user gets the content directly from the nearest node, so the transmission delay is smaller. At the end of the article, the work done in the paper is summarized, and the future work is prospected.
【学位授予单位】：北京邮电大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP393.02

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