【作者】 赵卫星；

【导师】 窦军；

【作者基本信息】 西南交通大学 ， 计算机应用技术， 2008， 硕士

【摘要】 交换技术可以说是新网络时代的核心,具有强大的寻址能力,不仅解决了网络智能化的问题,也促进了网络的发展。随着Internet网络规模的不断扩大和业务量的迅速增长,多层交换技术层出不穷,例如,第三层交换、第四层交换、标记交换等等。针对现有的Internet体系结构上在用户数据传输平台层次结构、传输效率和服务质量保障等方面存在的不足,西南交通大学四川省网络通信技术重点实验室提出了“单物理层用户数据传输与交换平台体系结构”(SUPA—Single Physical layer User—data transfer & switchingPlatform Architecture),以SUPA体系结构构建的网络称作SUPANET。SUPANET采用带外信令控制思想将Internet现有的协议栈保留在其“信控管理平台”(S&M-platform)上,以保持与Internet的互联互通能力,而利用面向以太网的物理帧时槽交换(EPFTS-Ethernet-oriented Physical FrameTimeslot Switching)技术将用户数据传输与交换平台(U-platform)简化为单物理层结构,为用户提供有服务质量保证的、面向连接的业务传输服务。本文主要分析EPFTS单物理层交换技术和多层交换技术在数据传输效率方面的性能,其中仿真的重点是分析数据传输在中间交换节点多个协议层次的处理时间(在输入端由下而上,输出端自上而下)产生的时延,分析EPF帧在单层和多层下的传输性能。文中分析了现有的多层交换技术,使用OPNET仿真技术对用户数据传输在层次结构改进基础上的性能进行了量化。对EPFTS和多层交换技术在服务质量、交换机制上进行了分析和比较,并对现有的以太网交换技术进行了改进,仿真分析了定长帧单层交换和多层交换下的数据传输效率。最后对基于EPF的单层和多层进行了仿真,对用户数据在中间交换节点的传输时延进行了量化,进一步从理论上支持了EPFTS单层交换技术在数据传输效率方面的优越性。本论文对单层交换的仿真采用了两种方案。第一种方案是在现有的以太网的二层交换机技术的基础上,为每个业务流分配一个虚拟的MAC地址,从而虚拟出多个“用户”,每个业务流在链路层形成以太网帧时,其源MAC地址域的值即为分配的虚拟MAC地址,建立一条基于“虚拟MAC地址”为标签的虚连接,实现了基于“虚拟MAC地址”的复用,直接进行MAC数据帧的转发。第二种方案是根据EPFTS用户数据传输的层次结构建立基于EPF帧单层仿真,在比较对象多层的仿真中,增加了EPF帧的解封和封装、查表等处理过程。论文的主要工作可以概括为:(1)分析现有的交换技术,并就交换层次带来的数据传输性能进行了仿真。(2)设计了基于现有以太网交换的单层交换技术的仿真仿案,对单层交换与多层交换技术在数据传输性能上进行了仿真比较分析。(3)设计了基于EPF帧的单层和多层仿真方案,对EPF帧在中间交换节点的层次处理延迟等性能进行了仿真对比。更多还原

【Abstract】 Switching technology can be said to be the core of the new Internet era, with a strong ability of address. It not only solves the problem of intelligent network, but also promotes the development of the Internet work. As the Internet continues to expand and the business volume grows rapidly, multi-layer switching technology developed day after day, for example, three-layer switching, four-layer switching, label switching etc. Internet was not catered for such converged service because of its’ complicated three-layer user-data translate platform, low transmission efficiency and absence of QoS insurance. For the very reason, SC-Netcom Lab (Sichuan Network Communication Technology Laboratory) has introduced the Single User-data transfer & switching Platform Architecture Network (SUPANET). The SUPANET simplifies User-data transfer & switching platform (U-platform) into a single physical layer platform by adopting the out-band signaling concept, while keeps existing protocol stacks of Internet in the Signaling & Management platform (S&M-platform) to enable interoperation with Internet. The key technique enabling the single U-platform is called EPFTS (Ethernet-oriented Physical Frame Timeslot Switching). SUPANET provides multimedia traffic with a QoS-insured, connection-oriented transmission service.This paper analyzes the network performance of EPFTS switching technology and multi-layer switching technology. The simulation is focused on the analysis of the transmission delay of user data in the switching node, and the transmission performance of fixed-length frame in multi-layer and single-layer switching. In this paper, first introduce the existing multi-layer switching technology. Using OPNET Modeler, the simulation of optimized the hierarchical structure is taken. Detailed analyzes and compares the multi-layer switching technology and EPFTS about QoS, switching mechanisms, design principles etc. the simulation of the transmission performance of EPF in a single layer and multi-layer is taken, the result further supports the theory EPFTS switching technology about the efficiency of data transmission.This paper presents two simulation programmers of the single-layer switching. The first idea is: on the basis of the existing two-layer switching technology in Ethernet, each application traffic in a "user host" is distributed a virtual MAC. When Ethernet frame is created for an application in data-link layer, its’ SOURCE MAC ADDRESS field was filled by the virtual MAC, and a correct virtual path is established by the map table of virtual MAC address. Implement the single switching and multiplexing. The second, according to the characteristics of user data transmission in EPFTS, establish a simulation model of the single-layer switching. In comparing object, increase the encapsulation, de-encapsulation, and look-up of the EPF frame.The author’s main contributions can be summarized as:A. Analyze the existing multi-layer switching technology, and simulate the transmission performance.B. On the basis of the existing switching technology in Ethernet, design the simulation programmer of the single layer switching, and simulate the programmer by OPNET.C. According to the characteristics of user data transmission in EPFTS, design the simulation model of the single-layer switching, and compare the transmission performance.更多还原