【作者】 张宏；

【导师】 李昕；

【作者基本信息】 北京邮电大学 ， 计算机科学与技术， 2015， 硕士

【摘要】 随着互联网的飞速发展,快速增长的流量和复杂的应用给传统的网络设施带来了巨大的压力。现有的网络在扩展性和灵活性上迎来了巨大的挑战。SDN的出现为网络管理和资源调度提供了新的思路。SDN把网络的控制层面和数据平面分离,增强了网络的控制逻辑,并且通过集中式的管理和可编程接口丰富了网络的扩展性。但是目前SDN仍然仅仅局限于数据中心和局域网的场景,由于网络设备的复杂性和网络结构的多样性,SDN在广域网中的应用还存在着很多限制。基于项目组对SDN在广域网中的应用研究[29][30],本文实现和优化了可用于广域网SDN的控制系统。该系统以代理技术、控制器技术和控制协议技术为核心,包含策略管理代理(Policy Management Agent,PMA)和策略管理服务器(Policy Management Server,PMS)。其中PMA对网络设备进行代理的方式进行信息采集和命令控制,PMS采用控制器技术,对网络设备进行管理和控制。PMS提供网络数据的查询和相应接口,可以在系统的基础上编写应用对网络进行编程控制。本文主要对系统的细节和实现方式进行了介绍。本文的主要内容如下:首先,介绍和分析了 SDN相关的研究现状;其次,介绍了项目组提出了 PMS-PMA架构;然后,对PMS-PMA系统的实现和优化方法进行了详细的说明,依赖于PMA,原本复杂的网络设备可以通过现有的网管方式如SNMP、CLI或NETCONF进行控制和访问。依赖于系统的核心组件PMS,系统可以对网络进行可编程的控制。同时,用户可以依赖于PMS提供的数据接口和通信机制来编写相关应用来优化和调整网络业务。最后,文章对该系统的性能和特点做了总结,并提出了对未来发展的展望。更多还原

【Abstract】 With the rapid development of the Internet,the increasing traffic and the complicated applications has brought great pressures to traditional network facilities.The existing network is facing huge challenge in extensibility and flexibility.SDN provides a new idea for network management and resource scheduling.It separates control plane from data plane,and enhances the control logical and extendibility of network through centralized management and programmable interface.But till now SDN is still a paradigm confined within data center and LAN area.Because of the complexity of the network device and the diversity of the network structure,there are still many restrictions on using SDN in WAN.Based on the research achievements of SDN for WAN system by our project team[29][30],this paper implement and optimize a SDN control system in WAN.The system implements the agent,the controller and protocol as core technology,contains Policy Management Agent(PMA)and Policy Management Server(PMS).The PMA,as an agent,is used to collect infomation from network devices and control them with command.The PMS,as a controller,can manage and control network device through the protocol between PMS and PMA.PMS also provide the query interface of network,infomation or other interface,so we can build application upon the system to control the network programmablly.This paper focuses on its implementation and optimization details.The main work of this paper is as follows:firstly,researches related with SDN were introduced and analyzed;secondly,our project team’s PMS-PMA architecture was introduced;thirdly,development and optimization of the PMS-PMA control system in WAN were introduced in detail.With PMA,the complicated network device now can be accessed and controlled through the existing network management methods such as SNMP,CLI and NETCONF.With PMS,which is the core component of the system,the system can control the legacy network flexibly.At the same time,users can develop corresponding applications to optimize or adjust network business through the data interface and the communication mechanism that PMS provided.Finally,this paper summaries the performance and characteristics of the system,and put forward the outlook on the future development.更多还原