第三层千兆比以太网交换机的设计与实现

以太网技术的发展和成熟,以及计算机性能和应用需求的增长促进了对第三层千兆比以太网交换机的应用.介绍了用MARVELL公司芯片为主芯片设计及实现的第三层千兆比以太网交换机,描述了交换机的各部分电路的设计和实现的功能,同时对其性能指标和实验测试结果的进行了说明.     

DCS-3926S交换机重生记

电脑网络的普及给人们的生活和工作，带来了极大的便利，这其中交换机的作用很关键。交换机可分为以太网交换机、令牌环网交换机、FDDI交换机、ATM交换机等。以太网交换机目前占局域网交换机的绝大多数，我这里就给大家介绍一款以太网交换机DCS-3926S（版本号：V2．10）的两类故障维修方法。     

电力配网光纤交换网工业交换机设备性能测试研究

电力通信配网基建项目将在所有变电站新增配网三层商用以太网交换机,并且无配套的配网主干光缆建设,考虑配网业务量的大小和主网光纤资源的稀缺,新接入的配网三层交换机将采用MSTP接入现有网络。所以未来将存在工业交换机、商业交换机、MSTP、光纤混合组网的问题。最后需测试商业以太网交换机需要采用何种光模块与二层工业以太网交换机进行互联。并且针对未来存在工业交换机、商业交换机、MSTP、光纤混合组网的问题,该报告将对工业以太网交换机的性能、二层功能、三层功能等内容进行测试,并且测试MSTP、百兆光纤、千兆光纤是否能混合组网。     

以太网交换机集群管理的设计与实现

随着以太网交换机在网络中应用规模的不断扩大,对以太网交换机的有效管理成为一个重要的研究课题。交换机集群管理技术的出现为这一问题提出了一个较好的解决方案。文章在国内起草的《以太网交换机集群管理技术规范》的基础上,重点介绍集群管理的设计与实现,结合实际工作中遇到的问题探讨了集群管理策略。     

IEEE 标准容限内以太网转发时延的测试与分析

本文在介绍以太网时延和以太网线速的基础上,对线速转发丢包问题进行分析.以测试交换机和Smartbits测试卡作为两个对接交换设备的模型,提出了时钟频偏是交换机转发时延的主要影响因素.推导了以太网交换机内部转发时延和频偏时延的计算公式,进行了以太网交换机一次、二次转发时延测试,理论计算和实验研究的结果验证了提出理论的正确性.     

无线传感网络与以太网无缝结合的应用研究

根据目前无线传感网络无法直接接入以太网的现状,根据以太网交换机的工作原理提出了eWSN交换机(使用以太帧格式的WSN交换机)、EI-eWSN交换机(带以太网接口的eWSN交换机)以及逻辑网络节点的概念,设计并实现了基于TCP/IP协议的无线传感网络系统.系统将以太网地址应用于无线节点,并将数据封装成以太帧格式进行传输,实现了无线传感网络与以太网的无缝结合.     

基于以太网交换机的仿真教学系统的设计与实现

以太网交换机是一种标准的局域网技术,其通过星型拓扑结构实现各功能的运用。交换机是为两台联网设备提供连接点的一种虚电路,可有效避免数据传输冲突,进而提高数据的网络传送速度。本文从以太网交换机的工作原理及功能入手,提出了基于以太网交换机的仿真教学系统的设计与实现。     

北电网络倾力打造新一代智能商用企业网

最近,北电网络先后在北京、上海、济南、成都和广州五大城市举办主题为"建设高性能、安全可靠的企业网络"的巡展,向客户介绍新一代商用企业网的发展前景和北电网络的智能商用企业网的基础架构,宣布推出支持这种智能商用网络的新产品(包括下一代二层以太网交换机、增强型VoIP及应用服务平台、IP-VPN服务网关和防火墙产品等),并推出新产品技术培训活动。北电网络的新一代智能商用企业网解决方案是建立在北电网络长期的电信和网络技术领先优势的基础上的,它包括了一系列最先进的产品:全新的BayStack5510和BayStack425交换机;全新的Passpo…     

基于以太网交换机平台的SNMP代理实现

网络管理是提高网络性能的有效方法,ＳＮＭＰ是当今最流行的网络管理协议。可管理交换机是交换机发展的趋势。本文介绍了基于以太网交换机平台的ＳＮＭＰ代理的实现。读者可以初步了解带有网络管理功能的交换机的硬件结构,ＭＩＢ库的构建,在Ｌｉｎｕｘ下ＳＮＭＰ代理软件的实现方法。同时,也介绍了在Ｌｉｎｕｘ下ＭＩＢ库的查询,守护进程的实现及Ｌｉｎｕｘ设备驱动的编写。     

Improved Message Forwarding for Multi-Hop HaRTES Real-Time Ethernet Networks

Nowadays, switched Ethernet networks are used in complex systems that encompass tens to hundreds of nodes and thousands of signals. Such scenarios require multi-switch architectures where communications frequently occur in multiple hops. In this paper we investigate techniques to allow efficient multi-hop communication using HaRTES switches. These are modified Ethernet switches that provide real-time traffic scheduling, dynamic bandwidth management and temporal isolation between real-time and non-real-time traffic. This paper addresses the problem of forwarding traffic in HaRTES networks. Two methods have been recently proposed, namely Distributed Global Scheduling (DGS) that buffers traffic between switches, and Reduced Buffering Scheme (RBS), that uses immediate forwarding. In this paper, we discuss the design and implementation of RBS within HaRTES and we carry out an experimental validation with a prototype implementation. Then, we carry out a comparison between RBS and DGS using worst-case response time analysis and simulation. The comparison clearly establishes the superiority of RBS concerning end-to-end response times. In fact, with sample message sets, we achieved reductions in end-to-end delay that were as high as 80 %.     

CQ Ethernet Switch Implementation on the NetFPGA Platform

In this paper, we present an original design for an Ethernet switch with crosspoint-queued crossbar switching fabric and analyze its performance. Recently, significant progress has been made on performance analysis of crosspoint queued crossbar switches using analytical and simulation methods. We propose a hardware implementation on the NetFPGA platform that can provide reliable results obtained in an experimental environment. It is shown that the proposed design performs as expected and outperforms reference design under some incoming traffic conditions.     

Traffic Shaping for Resource-Efficient In-Vehicle Communication

In-vehicle communication has become complex and costly due to the growing number of automotive network systems applied for different data types. In this work, our previously proposed in-vehicle network architecture that is based on Internet Protocol (IP) and full-duplex switched Ethernet (IP/Ethernet) is further investigated for real-time audio and video streaming. Quality-of-service (QoS) and resource usage are analyzed for selected IP/Ethernet-based network topologies. Traffic shaping is used to reduce the required network resources and consequently the cost. A novel traffic shaping algorithm is presented that outperforms other traffic shapers in terms of resource usage when applied to variable bit rate video sources in the proposed double star topology. In addition, a new architecture design is introduced for traffic shaper implementation in switches which operates on a per stream basis. Analytical and simulation results confirm that the proposed network architecture with traffic shaping is well-adapted for in-vehicle communication.      

一种针对SSM的二层转发方法

以太网交换机仅依据目的介质访问控制(Media Access Control,MAC)子层地址进行数据转发,指定源组播(Source Specific Multicast,SSM)数据进入交换机后可能被转发至其他频道的订阅用户。针对此问题,在分析了SSM协议模型的以太网交换问题的基础上,提出了SSM数据标识及源标识的加入方法,详细设计了SSM转发表的建立过程,给出了SSM数据的转发流程,并对方法的可行性进行了仿真验证。     

一种基于RIP和帧中继的网络设计

广域网和以太网是两种不同的网络技术,而小型局域网因为其业务多样性和分布离散性,使得其需要兼容不同协议的网络。提出一种基于以太网RIP路由协议和广域网的帧中继协议的网络设计,满足不同协议互通,为不同核心路由器和交换机之间配置RIP路由、静态默认路由和帧中继子接口,最终完成了该网络的布置。     

风起云涌的电子商务为运营商带来机遇

随着电子商务的日益兴起,电信运营商为企业提供基于IP的虚拟专用网(IP VPN)等数据服务的市场前景十分广阔.Tellabs 8800智能多业务路由器(MSR)以其对传统形式ATM/FR接入,以及新的以太网和IP接入的支持非常适合提供IP VPN.     

Rethinking Enterprise Network Control

This paper presents Ethane, a new network architecture for the enterprise. Ethane allows managers to define a single network-wide fine-grain policy and then enforces it directly. Ethane couples extremely simple flow-based Ethernet switches with a centralized controller that manages the admittance and routing of flows. While radical, this design is backwards-compatible with existing hosts and switches. We have implemented Ethane in both hardware and software, supporting both wired and wireless hosts. We also show that it is compatible with existing high-fanout switches by porting it to popular commodity switching chipsets. We have deployed and managed two operational Ethane networks, one in the Stanford University Computer Science Department supporting over 300 hosts, and another within a small business of 30 hosts. Our deployment experiences have significantly affected Ethane's design.      

浅论基于光纤通信的智能配电网通信技术

本文介绍了智能配电网的概念、智能通信网的特点,重点论述了工业以太网交换机和以太网无源光网络(Etherent Passive Optical Network,EPON)的原理和系统结构的异同,以及它们的应用.     

Limitations of current Ethernet switch architectures for enhanced flow control and service differentiation

One of the new challenges associated with full‐duplex Ethernet is that of providing for network congestion control. The IEEE 802.3x Standard does not specify the switch architecture for implementing PAUSE flow control or at what point a MAC Control entity actually generates a PAUSE frame. This is an implementation issue that is product specific and as a result many different switch architectures are possible. There are also a number of limitations of the PAUSE flow control mechanism when implemented in Ethernet switches. These issues have not been adequately addressed in the literature. In addition, multimedia traffic such as real‐time voice and streaming video are now being deployed over switched Ethernet networks, thus calling for congestion control with service differentiation for the various classes of traffic. Here we examine current Ethernet switch architectures and show that the PAUSE flow control when implemented in these architectures does not provide service selectivity and differentiation, making it unsuitable for real‐time traffic. Copyright © 2008 John Wiley & Sons, Ltd.     

基于嵌入式系统的以太网通信开发

采用基于ARM内核的嵌入式处理器LPC2478为核心的硬件平台和开源、内核可裁剪的实时多任务操作系统μC/OS-Ⅱ,提出了一种嵌入式以太网通信系统设计方案。阐述了硬件平台设计及软件驱动、多任务操作系统μC/OS-Ⅱ的移植以及TCP/IP协议栈的实现过程,实现了嵌入式以太网的数据传输。