Autonet: a high-speed, self-configuring local area network usingpoint-to-point links

Autonet is a self-configuring local area network composed of switches interconnected by 100 Mb/s, full-duplex, point-to-point links. The switches contain 12 ports that are internally connected by a full crossbar. Switches use cut-through to achieve a packet forwarding latency as low as 2 ms/switch. Any switch port can be cabled to any other switch port or to a host network controller. A processor in each switch monitors the network's physical configuration. A distributed algorithm running on the switch processor computes the routes packets are to follow and fills in the packet forwarding table in each switch. With Autonet, distinct paths through the set of network links can carry packets in parallel, allowing many pairs of hosts to communicate simultaneously at full link bandwidth. A 30-switch network with more than 100 hosts has been the service network for Digital's Systems Research Center since February 1990     

高速实时的一种邮件蠕虫异常检测模型

提出了一种基于带泄漏的积分触发测量方法的电子邮件蠕虫异常检测方法,用来检测邮件蠕虫在传播过程中的流量异常。根据邮件流量所表现出的明显的日周期特性和周周期特性,首先计算出当前邮件流量和历史邮件流量的最小Hellinger距离,通过带泄漏的积分触发方法把邮件流量的Hellinger积累起来,从而把邮件蠕虫在传播过程中没有明显流量特征的慢速酝酿阶段的异常特征进行积累,达到在其进入快速传播期之前检测出异常的目的。检测过程只需要检查邮件的流量信息,因而适合大规模高速网络的异常检测。     

An application of principal component analysis to the detection and visualization of computer network attacks

Network traffic data collected for intrusion analysis is typically high-dimensional making it difficult to both analyze and visualize. Principal Component Analysis is used to reduce the dimensionality of the feature vectors extracted from the data to enable simpler analysis and visualization of the traffic. Principal Component Analysis is applied to selected network attacks from theDarpa 1998 intrusion detection data sets namely: Denial-of-Service and Network Probe attacks. A method for identifying an attack based on the generated statistics is proposed. Visualization of network activity and possible intrusions is achieved using Bi-plots, which provides a summary of the statistics.     

Giga-bit CMOS equalizers for high-speed data links

Consumer electronics are experiencing an explosive growth in bandwidth requirements. This growth is driven by demand for fiber-to-the-home Internet connections, the increasing capabilities of in-home consumer devices as well as the demands of multimedia recording and playback in mobile devices. However, traditional copper channels and previous generations of optical fiber experience dispersive effects at data rates above 1 Gbps, leading to inter-symbol interference (ISI). This paper presents a finite impulse response filter-based feed forward equalizer (FFE) to reduce the effect of ISI on these channels. The efficacy is of the FFE is demonstrated by measuring the eye diagrams of a 10 Gbps signal transmitted through an optical fiber as well as a copper backplane with and without FFE compensation. The proposed FFEs successfully compensate ISI for both the optical and copper backplane links. All circuits are fabricated using a 0.18 μm CMOS process.     

Receiver structure trade-offs in equalized high-speed fiber-optic links

We experimentally investigate receiver structure trade-offs for equalized OC-192 fiber-optic links relying on Viterbi-algorithm-based sequence estimation. Our results prove that energy detection provides better performance than few-samples-per-bit detection at shorter distances of propagation. Alternatively, few-samples-per-bit detection provides longer reach at the cost of over-sampling and substantial power penalty for smaller amounts of accumulated dispersion.     

基于高速DSP的实时语音增强系统设计

随着移动通信技术的快速发展,语音增强的研究及其实际应用成为数字化通信的一个重要的研究方向。在数字信号处理技术的支撑下,许多优秀的语音增强算法的实时实现成为了可能。谱减法是一种运算量相对较小,增强效果明显,并且容易实时实现的语音增强算法,但是其缺点就是残留有音乐噪声。针对传统谱减法,本语音增强系统采用了一种改进算法,就是...     

The high-speed access network

The high-speed access network will replace part or all of the local-line distribution and will become an increasingly important element of the network. The network operator will wish to provide the full range of broadband and narrowband services to end users connected to the access network. To ensure that these can be delivered by the access network to end users in a consistent and standard manner and to allow interoperability of access networks and local exchanges, it will be necessary for the suppliers of access network equipment to support ETSI V5.1, V5.2 and V_b5 interfaces. This tutorial paper describes the fundamental principles and key functional capabilities of these interfaces     

高速采集图像实时压缩算法

为了解决高速图像采集给图像数据的实时传输和存储带来的困难,提出了一种基于提升形态Haar小波的面向自动目标识别(ATR)的图像压缩算法——目标形态小波图像编码(TMWC).该算法将形态Haar小波与数学形态学方法结合应用.首先将采集图像进行二维提升形态Haar小波分解,结合目标感兴趣区域(ROI)检测要求的特点,仅在尺...     

A new power-efficient CDMA-based transmitter for high-speed serial links

Conventional CDMA serial links suffer from the drawback that the number of transmitters is limited to only two in practical implementations due to the reduced voltage spacing between adjacent logic states of the transmitted data. In this letter, we propose a new CDMA serial link architect that allows an arbitrary number of transmitters to transmit data over the same channel while keeping the voltage spacing between adjacent logic states of the transmitted data to be the same as that of 4 pulse-amplitude-modulation serial link transmmitters. The effectiveness of the proposed architect is validated using the simulation results of a serial link with four transmitters designed in an IBM 130 nm 1.2 V CMOS technology.     

基于应用的高速网络入侵检测系统研究

传统的网络入侵检测方法基于传输层以下的数据包特性来检测入侵，因此存在一些难以克服的缺点，如易受欺骗（evasion)、误报警（false positive)多、检测效率低等，难以适应高速的网络环境。为了解决这些问题，本文提出将应用协议分析方法应用到网络入侵检测中，实现基于应用的检测，并提出了一个改进的多模式匹配算法，进一步提高检测的效率；同时针对高速网络环境，利用基于数据过滤的压缩技术与负载均衡技术提出了一个新的网络入侵检测系统结构模型，给出了系统的设计与实现方法。实验测试表明系统能够对吉比特以太网进行有效的实时检测。     

Effective network management via dynamic network anomaly visualization

Managed network has become increasingly large, complex, heterogeneous, and dynamic. With tremendous number of network components changing at any moment, deciding which events and changes are possibly abnormal and need further investigation is extremely challenging. While there has been widely adopted practice to log daily activities through standard file formats such as netflow, syslog, firewall, and IDS systems, it is vital for system administrators and network managers to be able to analyze the vast amount of log data in order to detect suspicious behaviors or patterns, possibly because of malicious users/applications or faulty devices. While there are automated systems that are available to generate warnings, whether such alarms are true or false, and more importantly, what are the underlying causes are still difficult to know. To bridge the gap between network logging and anomaly analysis, we design and implement a visualization tool that combines multiple useful visualizations together with algorithms such as graph link anomaly analysis. We study the effects of different visualization methods on detecting and analyzing network and system anomalous events and their causes and show that these views, when combined and linked together, may provide an effective alternative for network management and anomaly analysis. Copyright © 2016 John Wiley & Sons, Ltd.     

New pseudoternary line code for high-speed twisted pair data links

Regulated mark inversion (RMI) is a new pseudoternary line code which minimises high-frequency spectral components in a similar way to the FDDI TP-PMD MLT3 code, and yet also has a bounded running digital sum. The code has significantly lower DC content than standard MLT3, and a lower high-frequency content than run-length-limited MLT3 codes     

基于高速相关采样的锁模激光回波实时检测

针对锁模激光器微弱回波信号探测的需求,提出了一种基于高速相关采样和在线实时并行累加处理算法相结合的方法,对传统的模拟取样积分方法进行了改进,可实现无参考信号条件下的实时数字累加检测。设计并实现了一套基于该方法的锁模激光器微弱回波信号检测原型系统,使用12 bit@900 MSPS模拟-数字转换芯片（ADC） ADS5409对经光电转换之后的锁模激光回波信号进行波形采样,并利用现场可编程逻辑门阵列（FPGA）芯片Kintex-7实现对ADC的控制及在线数据处理。系统测试结果表明,对于重复频率为8 MHz、平均功率为0.04 nW的锁模激光回波信号,通过在FPGA内进行16 000次脉冲波形精确累加,可实现信号的有效检出,且从波形采集完毕到输出检测结果的延时小于100 ns,达到了高度的实时性。经900次重复实验,检测效率达到100%,且无虚警情况发生。     

星地激光通信链路地面集成测试系统的构建

针对星地激光通信链路的地面集成测试需求,提出了一种地面集成测试装置的构建方案,该方案可有效解决真实通信终端在地面环境下的相互捕获、跟踪、瞄准及通信等功能验证问题.     

一种使用光纤传感器的全光网络攻击检测研究

全光网络是通信网络发展的大趋势,光纤传感器因其所特有的特性具有电子传感器所无法比拟的优势。介绍了全光网络的结构和对全光网络可能采取的攻击方式,讨论了如何利用光纤传感器对针对全光网络的攻击进行检测。     

对一种网络攻击可视化方法的改进

根据一种简单有效的可视化方法，设计实现了一个网络攻击实时监测系统，实际网络中的测试表明该系统有明显优点，但准确性受门限值影响较大。为解决存在不足，引入暗网技术，根据仿真分析对系统进行相应改进，并在某专用网络中进行了测试。结果显示该系统比在用系统更早发现网络蠕虫，且时间提前明显。     

可视化技术及其在复杂网络上的研究与应用现状

可视化技术是有效、直观表达数据的重要手段,目前因特网等复杂网络上的数据量逐渐增多,为可视化技术带来了新的挑战。概述了可视化算法的发展历程,从平面图、层次图、有向图、立体图这4个图形分类出发,介绍了各自适用的可视化算法的发展情况。然后,以复杂网络为应用背景,从复杂网络拓扑结构、传播机理、入侵检测三方面的应用研究进展,说明了可视化技术对复杂网络研究的推动作用。最后,对几种适用于复杂网络的使用较广泛的可视化工具进行了分析和对比。     

安全协议和网络攻击分析

安全协议提供安全服务,是保证网络安全的基础。文章通过形式化分析方法,采用AVISPA分析工具对安全协议进行分析,总结出网络攻击方式的类型及其相应的解决办法。     

A new wave in network data links

Describes wavelength-division-multiplexed optical interconnects for LANs using monolithic VCSEL and resonant photodetector arrays     

云计算的电子政务网络安全可视化研究

本论文的主要内容就是对云计算的电子政务网络安全可视化研究的简要分析,希望能够为电子政务网络发展做出一定的贡献.