OpenDaylight平台上基于业务需求路由引擎的研究与实现

发布时间：2018-03-26 05:56

本文选题：SDN　切入点：OpenDaylight　出处：《北京邮电大学》2017年硕士论文

【摘要】：近年来,软件定义网络(Soft Defined Network,SDN)的诞生无疑推动了传统分布式网络向集中式网络的过渡,而OpenDaylight是目前最为流行的开源SDN控制器,其开放的应用编程接口,以及控制与转发分离的思想被业内所接受。但是OpenDaylight仅仅实现了网络转发的基础功能,并没有针对各种各样的业务以及应用做相应的拓展,所以其并不能良好的满足当前网络多样化的业务需求,无法灵活的选择路由策略,这与SDN开放北向接口,面向业务的原则相违背,严重制约了软件定义网络的发展,而这正是木文所要解决的主要问题。本文基于 OpenDaylight平台,利用控制平面的可编程性质,研究并实现了基于业务需求的路由引擎,该引擎可以根据不同的业务需求收集底层网络的统计信息,从而作出最佳的路由决策。本文做的主要工作有:(1)通过分析OpenDaylight中web界面的开发步骤以及Yang模型的定义方法设计并实现了业务描述模块来描述具体的业务需求,获取描述参数作为路径计算的依据;(2)通过分析OpenDaylight中网络拓扑的获取流程,监听底层网络节点的变化通知获取网络的全局拓扑,同时自定义Graph数据结构存储拓扑数据;(3)根据具体的业务需求利用控制器向底层交换机下发封装了时间戳的 LLDP报文、Echo request消息以及OFPT_STATS_REQUEST消息,获取网络的带宽和时延信息,并将这些信息记录到Graph数据结构中;(4)设计并实现了路径计算模块,利用Dijkstra算法以及Yen算法分别计算基于跳数、时延和带宽的转发路径,并将结果写回到DataStore; (5)对本文设计的路由引擎进行功能性测试,确定其满足设计要求。本文在OpenDaylight基础上设计并实现了基于业务需求的路由引擎,经过测试,该引擎达到了预期效果,能够根据不同的业务需求触发不同的路径计算过程,从而得到最佳的路由决策。
[Abstract]:In recent years, the birth of soft Defined Network (SDN) has undoubtedly promoted the transition from traditional distributed network to centralized network. OpenDaylight is the most popular open source SDN controller, and its open application programming interface. The idea of separation of control and forwarding has been accepted by the industry. However, OpenDaylight has only realized the basic function of network forwarding, and has not made corresponding expansion for various services and applications. Therefore, it can not meet the needs of the current diversified network services, and can not flexibly choose the routing strategy, which is contrary to the SDN open northward interface and service oriented principle, which seriously restricts the development of the software defined network. Based on the OpenDaylight platform and the programmable nature of the control plane, this paper studies and implements the routing engine based on the business requirements. The engine can collect the underlying network statistics according to different business requirements, The main work of this paper is to analyze the development steps of web interface in OpenDaylight and the definition method of Yang model to design and implement the business description module to describe the specific business requirements. Obtaining description parameters as the basis of path calculation) the global topology of the network is obtained by analyzing the process of obtaining the network topology in OpenDaylight, monitoring the change notification of the underlying network node, and obtaining the global topology of the network by monitoring the change notification of the underlying network node. At the same time, the custom Graph data structure is used to store topology data. According to the specific service requirements, the controller sends the time-stamped LLDP message and OFPT_STATS_REQUEST message to the bottom switch to obtain the bandwidth and delay information of the network. The path calculation module is designed and implemented by recording these information into the Graph data structure. The forwarding paths based on hops, delay and bandwidth are calculated by using Dijkstra algorithm and Yen algorithm, respectively. The results are written back to data Store; 5) the routing engine designed in this paper is tested to satisfy the design requirements. This paper designs and implements a routing engine based on business requirements on the basis of OpenDaylight. The engine achieves the desired effect and can trigger different path calculation processes according to different business requirements, thus obtaining the best routing decision.
【学位授予单位】：北京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP393.0

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