IP高速骨干网络交换标准——MPLS

1多协议标签交换多协议标签交换(MPLS,multi-protocollabelswitching)属于第三代网络架构,是新一代IP高速骨干网络交换的标准,由因特网工程任务组(IETF)提出,由思科、ASCEND、3Com等网络设备厂商主导。MPLS是集成式的IPoverATM技术(即在帧中继或ATM交换上结合路由功能),数据包通过虚拟电路传送,只需在OSI第二层(数据链结层)执行硬件式交换(取代第三层(网络层)软件式选路)。它把IP选路与第二层标签交换整合为单一的系统,因此可解决Internet的路由问题,缩短数据包传送的时延,加快网络传输速度,适合于多媒体信息传送。MPLS最大…     

基于GNS3的宽带交换技术仿真实验设计

本文针对在真实设备上做实验存在的不能多人同时配置数据的问题,基于网络仿真软件GNS3设计了有关多协议标记交换(MPLS)的实验。实验内容包括路由协议实验、MPLS实验和MPLS VPN实验。路由协议包括RIP、EIGRP、OSPF。每种类型的实验又分为初级、中级和高级。文中详细给出了MPLS VPN高级实验的实现方法,包括数据配置过程和测试方法。根据学生实验后的反馈信息,本文给出了改进方案。     

MPLS VPN不同解决方案的比较分析

MPLS VPN是一种基于多协议标记交换(MPLS)技术的IP虚拟专用网络(VPN),是通过在网络路由和交换设备上应用MPLS技术,简化核心路由器的路由选择方式,并结合传统路由技术的标记交换来实现的.本文介绍了MPLS VPN的基本原理和发展现状,分析和比较了主要的2层(L2)和3层(L3)MPLS VPN技术.     

MPLS技术及其应用

Internet核心网中的路由／转发技术的最新发展是多协议标签交换(MPLS)。MPLS将IP路由控制和第二层交换的简单性无缝地集成起来，ATM与IP技术的有机结合，在不改变用户现有网络的情况下能提供高速、安全、多业务统一的网络平台，将在下一代网络中的选路、交换和分组转发中扮演非常重要的角色，满足网络用户多种多样的需求。     

MPLS技术在电子政务网中的应用

MPLS(多协议标签交换)是新兴的一种路由技术。这种新技术通过优化网络可以给服务提供商提供更多的增值服务。MPLS简化了数据包的路由，使网络最优路径的选择更为容易。MPLS还支持通过保留带宽和实现传输优先级的QoS(服务质量)管理。另外，MPLS的一个关键优势在于它支持虚拟专有网络(VPN)。因此，它允许服务商在网络上销售他们的服务给他们的许多客户。MPLS是互联网技术自然发展的一步。它以现存IP协议为基础。能被很容易地和目前的路由协议(BGP-4，IS-IS，OSPF)集成。而且现在很多在互联网上运行的核心路由器都可以通过软件升级的方式支持MPLS。     

MPLS在城域MSTP中的应用

为解决QoS等IP网络存在的问题，每个ISP都渴望寻求一种能够结合快速交换技术和IP路由技术优势的网络解决方案．MPLS(多协议标签交换技术)应运而生。标签交换技术就是致力于把L2层交换技术的最优属性(通常由ATM或帧中继具体实现)与L3层路由技术的最优属性(由IP具体实现)紧密结合起来，其中多协议标签交换(MPLS)是目前标准最统一、最具发展前景的标签交换技术。MPLS由因特网工程任务小组(IETF)制定，始于1997年初．其目标是实现在大规模IP网内通过ATM和帧中继等多种媒介实现保证QoS的快速交换。     

浅谈基于移动IP的移动通信系统优化

本文提出了一种方案来综合移动IP和MPLS协议.MPLS技术是一项利用绑定在IP包中的标记,通过网络进行数据包转发的技术,它结合了第二层(数据链路层)交换的快速性和第三层(网络层)路由选择的可扩展性.是IP与ATM技术相结合的一种较好的解决方案.文章将MPLS技术引入移动IP中.充分利用了MPLS技术的优点.使得移动IP不再需要利用隧道来传递分组.相反,整个的转发过程都是在MPLS层上处理.MPLS交换远远快于传统的IP分组转发业务.大大减少了传输和分组处理时延并且扩展了移动IP的可用性.     

浅析OSPF动态路由协议

对目前在通信基础网络中广泛使用的OSPF动态路由协议进行分析,从路由表、动态路由协议、OSPF路由算法、OSPF网络规划等方面分别进行了阐述,为优化网络结构,提高网络管理水平打下基础。     

MPLS的原理及技术融合

MPLS(Multiprotocol Iabel Switching，多协议标签交换技术)属于第三代网络架构，是新一代的IP高速骨干网络交换标准，由IETF(Internet Engineering Fask Force，因特网工程任务组)所提出。MPLS是一个可以在多种第二层媒质上进行标记交换的网络技术。这一技术结合了第二层的交换和第三层路由的特     

MPLS VPN在CMNET-GD的应用

MPLS(多协议标签交换)是有效结合第2层(数据链路层)的交换技术和第3层(网络层)路由技术的基于标准的下一代Internet解决方案。本文主要介绍了MPLSVPN的网络构成,并重点介绍了该技术在CMNET-GD的应用,展示了MPLSVPN技术良好的应用前景。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.