【作者】 王金春；

【导师】 隗永安；

【作者基本信息】 西南交通大学 ， 通信与信息系统， 2003， 硕士

【摘要】 随着互联网的迅速发展、以网络为中心的计算时代的到来，通信网正在完成从电路交换技术转向分组交换技术，特别是无连接IP技术的战略性转型。同时人们对网络带宽，网络性能和网络管理的要求也都愈来愈高，这些都对网络互连的核心设备——交换机和路由器的设计实现提出了新的挑战。 本文首先从两个方面阐述了在这种需求下以太网技术的发展历程：一方面传递速率从最初的10Mbps、100Mbps发展到现今的1Gbps和10Gbps；另一方面网络也从共享发展到交换，并从第二层交换到目前流行的第三层交换。该部分重点解释了千兆以太网的体系结构和协议规范，对PCS、PMA和PMD子层的实现技术和有关算法的设计思想进行了深入的分析；并对设计中用到的几种物理层芯片进行了介绍；此外该部分还分析了传统第二层交换机和路由器的局限性，对集第二层交换和第三层路由优点于一身的第三层交换技术进行了讨论，阐述了以太网第三层交换机的一般原理和实现，并介绍了其优点和应用。 之后文章对多层交换芯片BCM5615的交换结构、内部各个功能模块的原理实现以及芯片中的二、三层数据流程作了比较详细的分析。在此基础上提出并实现了一款基于BCM5615的千兆路由交换机。接着文章详细介绍了该款交换机的硬件设计，给出了包括微处理器子系统模块、L2／L3交换模块、FE接口模块、千兆接口模块以及带外管理模块在内的主要模块的电路设计实现，对各模块之间的接口电路也作了介绍，文章最后对软件的总体结构进行了分析。本文的实现方法对基于其他交换芯片的设计同样具有参考价值。更多还原

【Abstract】 Along with the fast development of the Internet, the main technology used in the communication network is changing from circuit-switched technology to the packet-switched technology, especially to the connectionless IP technology. Meanwhile, the people have more and more urgent requirements on the bandwidth, performance and management of network. Such requirements are challenging the core devices used for interconnecting the networks, such as the switches and routers.. This thesis first describes the development procedure of Ethernet technology from two aspects: 1) The transmission speed has evolved from 10Mbps/100Mbps to 1 Gbps/10Gbps. 2) The network has developed from shared mode to the switched mode. In this part, the system structure and protocol specifications of Gigabit Ethernet (GE) are described in detail. The implementation methods and related algorithms of PCS, PMA and PMD sublayers are analyzed. The physical chips used in the design are also introduced. Furthermore, the limitations of traditional Layer 2 switches and routers are also analyzed. The Layer 3 switching technology, which combines the advantages of Layer 2 switching and Layer 3 routing is discussed. The general principles and implementation methods of Ethernet Layer 3 switch are described, and its advantages and applications are also introduced.In the later part of the thesis, detailed analysis is made for the realization principles of the switching structure and internal function modules of multiplayer. switching chip BCM5615. The data flows in Layer 2 and Layer 3 are analyzed in detail. According to the analysis, the thesis describes the implementation of a gigabit routing switch based on BCM5615. The thesis also describes the design of the switch hardware, including microprocessor subsystem module, Layer 2/Layer 3 switching module, FE interface module, GE interface module and out-band management module. The interface circuits among modules are introduced as well. Finally, the thesis estimates the overall structure of the software.The implementation methods described in the thesis are also valuable references for the design of other switches based on other switching chips.更多还原