基于关键IP核加固的片上网络容错机制

片上网络中的路由器故障将导致与其相连的IP核不能通信,严重影响了片上网络的性能.因此提出一种基于片上网络2D-mesh结构的容错机制,通过将关键IP核的资源网络接口与相邻节点的资源网络接口相连进行IP核的加固,在每个路由器的各个端口中配置邻居节点状态寄存器标示邻居节点的好坏,在路由计算时通过检查寄存器绕过故障路由器,同...     

基于NAT技术的即插即用服务实现

随着互联网的发展,越来越多的网络服务提供商需要客户固定设备的IP信息,致使用户更换使用场所时需重新设置而造成不便.提出了基于网络地址转换技术的网口即插即用服务,该技术利用Linux系统平台中IPTABLES等功能进行源地址转换及目的地址转换.通过测试,用户可以在不更改用户PC任何TCP/IP协议配置的情况下接入因特网进...     

NoC 中基于数据包分类的功率门控策略

随着制造工艺的精进,静态功耗逐渐成为路由器的主要功耗来源之一。 针对基于片上网络架构的多核系统高功耗问 题,提出了一种基于数据包分类的功率门控策略,并修改了路由器架构。 首先对数据包进行分类,其次利用旁路对分类数据包 进行不同的处理,来绕过休眠路由器,从而降低由于功率门控的应用而导致的额外数据包延迟和功耗。 旁路可以保证路由器休 眠时的数据包传输,增加休眠路由器的休眠时间,减少静态功耗。 数据包的分类处理使得路由器的休眠和唤醒更加合理高效。 仿真结果表明,本文方案能明显减少路由器的静态功耗和网络的延迟,相比传统的功率门控技术,最大减少 72. 4%静态功耗和 16. 8%平均数据包延迟;相比经典的采用功率门控的旁路路由器,减少 12. 4%静态功耗和 4. 7%平均数据包延迟。 路由器的额 外硬件开销仅增加了 3. 2%。     

多接口能源路由器主回路结构及功能仿真

能源路由器是构成未来能源互联网的重要设备。在分析基于能源路由器的分布式能源共享方式的基础上,分析了能源互联网对能源路由器的基本要求,并提出了一种基于电力电子变换器的模块化多接口能源路由器主回路结构,包括储能及其变换器,公共直流母线和能源接口,其中能源接口根据其用途可分为网络能源接口和本地能源接口。简要介绍了能源路由器各个模块的控制策略,在相应控制策略下,能源路由器一方面能够满足本地分布式电源的接入和负荷的供电需求,另一方面能够控制其多个网络能源接口的交换功率,实现多个能源路由器之间或与外部电网之间能量的点对点传输,即能源路由功能。提出了一种能源路由器储能和各网络能源接口之间的能量管理策略,能够实现分布式电源就地消纳及能源的网络共享。在MATLAB/Simulink环境下建立了能源路由器仿真模型,对能源路由器的动态响应特性和能量管理策略进行了仿真,结果验证了所提出的能源路由器主回路结构及控制策略的正确性和有效性,验证了能量管理策略的可行性。     

IPv6下边界网关路由协议的实现

路由器作为互联网的核心,在向IPv6转变的过程中,也需要有相应的改进。同时由于专用路由器昂贵的价格,以及Linux操作系统强大的网络功能和开放系统源代码的特性,对Linux操作系统进行适当的软件配置来打造软路由日趋成为研究热点。本文就基于Linux打造支持IPv6的边界网关协议的路由器进行了讨论和研究。     

浅谈IP over SDH技术

为适应数据通信网，尤其是Internet上急剧增长的业务需求以及解决随之而产生的网络拥塞、时延和服务质量等问题，IP over ATM、IP over WDM等技术应运而生，成为未来Internet技术、多媒体通信网络技术的竞争焦点，重点从支持IP over SDH技术的协议，新型千兆比特路由器的应用等方面阐述了IP over SDH技术的特点。     

Prototype implementation of fast and secure traceability service over public networks

Internet communication message protocol (ICMP)‐based traceability methods are widely used to trace packets over the Internet; however, in their attacks, adversaries likewise use ICMP packets. Furthermore, the lack of security in ICMP‐based traceability results in failures for many current traceability methods. Moreover, current routers are unable to provide extended services to Internet users and applications. To address this need, our laboratory has introduced the service‐oriented router (SoR). SoR is middleware that can be implemented on a Cisco AXP and Juniper JunosV App Engine. In this paper, we propose a secure method of providing packet traceability over public networks using SoR features. We implemented a secure packet traceability service prototype on the ns‐3 simulator. The test results conclude that there is a maximum additional cost of 48.69 and 123.91 μs of processing overhead per packet in each hop when the proposed secured traceability service is used with a 128‐bit key space in AES‐GCM and AES‐CTR modes, respectively. Moreover, for 256‐bit key spaces, AES‐GCM and AES‐CTR modes consumed additional 47.18 and 123.25 μs, respectively, over the plain traceability. Yet, from the evaluations on the test bed topology, it clearly shown that the proposed method was 79% faster than the conventional trace route method in providing the secured end‐to‐end traceability. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

能源互联网中H桥直流能源路由器的研究

能源互联网是构建在可再生能源发电和分布式储能装置基础上的新型电网结构,也是未来电网发展的新趋势。能源路由器主要任务在于能量的调节及信息的实时传递,是能源互联网的核心部分。文中提出的H桥型直流能源路由器,既可作为各种分布式能源发电装置和负载接入能源互联网的接口,又可实现能量的双向流动及协调控制,具有结构简单、适用范围广、经济成本低等特点,尤其是对直流微电网形式的能源互联网具有更强的适用性。文章首先介绍了能源路由器的国内外发展动态;然后介绍了能源路由器的应用领域及功能特性;接着对H桥型直流能源路由器的工作原理进行分析,并建立了H桥直流能源路由器的PSCAD仿真模型;最后,通过搭建相应实验平台验证了H桥型能源路由器能量的双向流动。     

智能变电站过程层网络流量控制和同步方法研究与实现

为解决智能变电站过程层网络装置过分依赖对时网络问题,及智能变电站过程层网络SMV报文间、SMV和GOOSE报文间及GOOSE报文间的相互干扰问题,提出了通过在交换机上实现延时可测技术和业务流量管理技术有效解决过程层网络现存的两个主要问题。延时可测技术通过GOOSE、SMV报文携带经过交换机的延时值实现时间同步。业务流量管理技术通过基于目标MAC地址的流量控制方法解决过程层网络报文间相互干扰问题。     

On the point-of-presence optimization problem in IP networks

This paper presents a model for the point-of-presence (POP) optimization problem in Internet protocol (IP) networks, where a POP is a node composed of several interconnected co-located backbone routers. This problem consists of selecting the number of routers and their types, selecting the interface card types, connecting the access and the backbone links to the ports, selecting the link types between the co-located routers, and routing the traffic within the POP. A detailed example solved by using a branch-and-bound algorithm is presented along with results for a set of randomly generated problems. The results show that fair-sized problems can be solved to optimality within a reasonable amount of time.     

浅析NAT技术在网络扩展中的应用

IP地址是一种有限的资源，它的使用受到严格控制。NAT(网络地址转换)技术可以在不申请新的网络地址和更新路由表的情况下，使不具备合法IP地址的私有网络与公用网络之间互相访问，从而实现网络扩展。     

Torus拓扑结构的双端口NoC模型与性能分析

为了充分利用片上网络的并行通信能力,挖掘网络带宽利用率,设计了一种高性能的双端口片上网络。该网络中每个路由节点提供两个本地端口,每个资源节点采用对角线的方式接入到网络中两个路由节点上,并针对这种接入结构提出一种目的节点切换方法用于提高网络的并行通信能力。同时,为进一步提高新路由结构的性能,将双端口路由节点引入Torus结构,构造了基于Torus的双端口网络的模型,并对其进行性能评估。实验结果表明,基于Torus结构的对角线双端口NoC在单目事物实验中较单端口网络平均吞吐量和平均包延迟最大改善了83.3%和55.9%,在双目事物实验中较同一维序双端口网络平均吞吐量和平均包延迟最大改善了91.1%和54.3%。     

Research on switching throughput of traffic manager in core routers

A general model is made to analyze switching throughput of traffic manager in core routers. By designing a real traffic manager that uses the OC-48c interface, the whole system is analyzed and it is pointed out that at least four HSSLs should be employed per CSIX interface when using Vitesse’s GigaStream switch chipset. Meanwhile, at the CSIX interface, the CFrame should be constructed according to the actual size of the last cell of each IP packet. The above principles can guarantee forwarding of IP packets at line rate. A general relationship between throughput and buffering scheme of IP packets in the external memory is given, which is useful in the design of switch fabric in core routers. __________ Translated from Acta Electronica Sinica, 2005, 33(7): 1243–1246 (in Chinese)     

MPLS 的服务质量

随着网络流量的不断增加，网络的业务范围不断拓展，如IP Phone,IP Fax，可视电话等，各种实时与多媒体业务对数据传输提出了低时延，低抖动等更高的要求，传统的IP网络已经很难保证QoS，这已成为网络进一步发展的瓶颈。为此，IETF提出了IP网络中实现了QoS的2种模型；综合服务模型和差分服务模型，其中差分服务模型是发展方向。与此同时，对QoS具有有良好保证的MPLS技术也应运而生，面介绍了2种模型的基本概念之后，讨论了MPLS对QoS姝具体技术实现，诸如按照传统路由器的方式进行选路的拓扑驱动MPLS，为特定服务的IP包创建隧道的约束路由的MPLS。     

Packet sniffing: a brief introduction

Packet sniffing is a method of tapping each packet as it flows across the network; i.e., it is a technique in which a user sniffs data belonging to other users of the network. Packet sniffers can operate as an administrative tool or for malicious purposes. It depends on the user's intent. Network administrators use them for monitoring and validating network traffic. Packet sniffers are basically applications. They are programs used to read packets that travel across the network layer of the Transmission Control Protocol/Internet Protocol (TCP/IP) layer. (Basically, the packets are retrieved from the network layer and the data is interpreted.) Packet sniffers are utilities that can be efficiently used for network administration. At the same time, it can also be used for nefarious activities. However, a user can employ a number of techniques to detect sniffers on the network and protect the data from sniffers. The technique behind packet sniffing on shared bus broadcast LANs is explained.     

Cellular digital packet data

Cellular digital packet data (CDPD) offers on-the-go users access to a low-cost, widespread, wireless data network. CDPD can be overlaid on existing analog cellular systems, and share their infrastructure equipment on a non-interfering basis. Basically, CDPD transmits packet data over idle cellular channels. It autonomously switches to another channel when the current channel is about to be assigned for voice usage. CDPD does not communicate with the underlining cellular network. However, CDPD does use its knowledge about the channel assignment algorithm of the cellular cell to predict the channels available for CDPD use. CDPD may serve as the wireless extension to other data networks (e.g., Internet) or public switched telephone networks. It supports connectionless network services which have packets called network protocol data units (NPDU). Every packet is routed individually based on the destination address of the packet and knowledge of the current network topology. Initially, CDPD provides two connectionless network services: the standard open systems interconnection connectionless network protocol and the Internet protocol     

智能配网数据网的研究与应用

结合目前已经建立的电力调度数据网运行情况,利用现有的网络路由交换设备加上新设备建立了智能配网数据网,在节约成本的基础上保证了高带宽和高可靠性。文章对智能配网数据网在网络拓扑、链路及带宽、节点配置、路由协议、IP地址规划、多协议标签交换部署、网络可靠性、网络安全等方面的设计进行了介绍。     

SPDnet在配电自动化通信中的应用

通过总结目前工程实施中关键技术相关经验及对比配电子站通信方案,提出了采用SPDnet作为大量DTU连接主站的通信平台以解决集中式配电自动化系统通信中存在问题的方法,结合SPDnet的技术特点给出了两种具体的应用方案。一是在SPDnet接入层路由器的VPN实例上绑定从IP引入配电的专用IP地址规划,并在供电公司SPDnet边界路由器上配置ACL策略来禁止配电专用IP网段的信息跨界路由;二是采用内部服务器NAT映射技术实现DTU以私网方式接入SPDnet。     

调度自动化系统双网卡热备冗余机制的设计与实现

为了提高调度自动化系统中网络通信的可靠性,提出一种基于双网卡的热备冗余机制。该机制包含了故障监测、故障切换和故障恢复算法。故障监测采用监测程序向核心网络设备发送探测报文的方式;若设备故障则由故障切换程序进行地址的切换;同时监测程序始终保持对故障设备的监视,一旦恢复正常则由切换程序进行故障恢复。文中实现的机制具有实现方便、部署简单、通用性好、可靠性高等特点,在电网调度自动化系统中已得到应用。     

含能量路由器的交直流混合配电网潮流计算

能量路由器(energy router, ER)作为新兴电力电子设备,可以实现电能在电力系统中的灵活分配。分析ER对系统的影响,研究以ER为配电枢纽的交直流混合配电网潮流计算方法,对实现配电网的优化运行具有重要意义。文中首先基于改进交替迭代法建立ER的稳态潮流模型,并对ER直流端口采用下垂控制策略,结合传统解耦法,提出一种适用于含ER的配电网交直流解耦迭代潮流计算方法。以含有多个ER的IEEE 14节点和IEEE 69节点配电系统为算例进行仿真计算,验证所提方法的正确性与收敛性。为分析ER对系统运行的影响,对不同场景下IEEE 69节点测试系统进行仿真计算,证明ER在系统中可以支撑节点电压,减小系统运行损耗。