网络链路冗余的设计与实现

热备份路由协议主要是提供一种在IP传输失败情况下不中断服务的机制。在文中对热备份路由协议的原理进行了介绍,并给出了一个高可靠性园区网的实例。     

一种基于BFD检测的IP快速重路由解决策略

BFD协议具备标准化规范、通用性好、介质和协议无关性等特点,在网络快速故障检测方面,具备良好的应用优势。文章在研究路由协议重路由、IP网络的故障快恢复相关技术研究得基础上,结合BFD快速检测机制,设计出提前路由备份算法的IP快速重路由技术,在链路出现故障等失效到路由重新收敛;通过仿真工具进行仿真测试,减少报文丢失,大幅度提高网络的故障恢复速度,实现50ms内的路由链路收敛时间,满足用户需求。     

浅析网管网改造规划和设计

本文根据网管网的改造规划和设计进行叙述,从分析的角度讲述了方案的目标和总体设计,从网络拓扑结构设计、IP地址规划、路由协议规划、VPN实例规划、网络备份及流量分担,到网络安全保障等方面进行总体设计,涵盖网络的整体设计到局部规划,为方案的实施提供依据和保障。     

基于消息的高可靠IP电话网关系统原理与实现

综合比较正在发展的H.323IP电话网关的几种实现高可靠性的方法后,提出了一种基于消息传送实现两个信令实体热备份的方案及其具体实现,并指出了今后的IP网上应用层协议冗余备份的实现可能方向。     

浅谈HSRP技术在空管CDM网络冗余设计中的应用

CDM(协同放行系统)作为机场空管的业务运行系统,在日常运行中对IP网络有着高可靠性的要求,本文主要介绍了目前主要的热备份路由协议HSRP的实现原理,以及HSRP技术在西北空管CDM网络中的应用方式,以及在运维时要注意的问题.     

IP接入网多种接入方案的性能比较

IP接入网主要有直接接入、第二层隧道、第三层隧道、路由器及多协议标记交换等接入方式。通过对这些 IP接入方案的性能比较以及当前 IP接入网研究重点的阐述 ,探讨未来 IP接入网的发展趋势及应用前景     

卫星IP通信网设计技术

卫星通信网用于传输IP业务时面临一些特有的问题。论述了卫星通信特有的长延时和误码特性对各种IP业务的影响并给出了一些切实可行的解决办法;着重阐述卫星IP通信网设计时,如何进行路由协议选择、提高卫星信道利用率、广播风暴、备份信道切换路由问题以及关注IP信道质量如何衡量等问题,给出了每个问题的解决办法和一些切实可行的措施,对有些问题专门做了研究试验,提供了一些试验测试数据、曲线和有关示意图。     

IS-IS路由协议分析与大型网络路由设计

作为链路状态路由协议,IS-IS路由协议具有极其优异的性能,适合大规模IP网络内部网关协议路由协议(IGP)。大型的IP网络中路由的规划与设计是一项复杂的任务,IS-IS适合大型IP网络的域内路由协议。本文针对IS-IS协议的特点,结合探讨区域的规划与设计、IP规划、CLNS地址规划、链路状体级别的规划等多个方面对IS-IS路由协议进行分析和提出设计思路。     

静态路由协议的重分发与备份

对于网管人员来说,在整个IP网络上运行单个路由协议,特别是动态路由协议进行自动选路,肯定是最理想的选择。但如果某些旧设备无法支持选定路由,或者是为防止动态路由协议选定的网路不通或配置有误时没有备份路由,在这种情况下,通常的做法是保留部分静态路由协议,并在路由器上利用动态协议重分发（redistribution）这些静态路由,这是在较为复杂网络中部署静态路由最为便捷的一种方法。     

在基于MPLS的层次化移动IP网络中支持DiffServ的研究

MPLS支持DiffServ、流量工程,能为网络提供较好的QoS保证,而移动IP(MIP)能为移动设备提供较好的移动性支持。文章探讨了在无线接入网中MPLS和MIP结合实现DiffServ的方案,并给出了一种在基于MPLS的层次化MIP网络结构中支持DiffServ的体系结构,设计了其节点功能模型和关键协议。方案中利用了层次化结构的区域注册和重路由机制,减少了切换时延和网络的信令负荷。     

IP城域网业务控制层BRAS可靠性设计方案探讨

BRAS作为IP城域网业务控制层管理用户及流量的核心设备,其可靠性设计是实现城域网高QoS的重要保证。在目前BRAS热备技术尚不完善的情况下,本文提出了端口聚合、分场景冷备等多种可靠性设计方案,并对各种方案的优劣势及适用场景进行了分析和探讨。     

基于热备份的主备倒换在高端路由器中的应用

从高端路由器的可靠性出发，提出提高可靠性、减少故障持续时间的关键在于减少路由器主备倒换时间。文中通过对传统的主备倒换与热备份下的主备倒换进行比较，分析了热备份下的主备倒换在节省业务板和路由板的重启时间、业务板恢复配置时间、路由板路由学习聚合时间等方面的优势。同时详细介绍了基于热备份的主备倒换在高端路由器中的主要实现步骤，并对其技术特点和给用户提供的解决方案进行了阐述。     

一种新的城域网大客户专线热备保护方案

本文通过对城域网大客户专线的保护现状进行分析,提出了一种新的热备保护方案:由一个管理VRRP实现批量大客户专线的主备切换,部署BFD技术来保证管理VRRP处于合适状态。大客户专线本身不启用VRRP协议,而是在配对SR上配置相同的IP地址。通过备用SR对外发布小COST值的业务路由来实现专线接口主备切换后的下行流量切换。采用本方案,能够节约公网IP地址,实现故障时大客户专线的批量快速自动切换,提升大客户专线的可靠性。     

一种新的城域网大客户专线热备保护方案

通过对城域网大客户专线的保护现状进行分析,提出了一种新的热备保护方案：由一个管理VRRP实现批量大客户专线的主备切换,部署BFD技术来保证管理VRRP处于合适状态。大客户专线本身不启用VRRP协议,而是在配对SR上配置相同的IP地址。通过备用SR对外发布小COST值的业务路由来实现专线接口主备切换后的下行流量切换。采用本方案,能够节约公网IP地址,实现故障时大客户专线的批量快速自动切换,提升大客户专线的可靠性。     

基于 ForCES的转发件中Xscale层的研究和实现

为了改进目前IP路由器的可扩展性和灵活性等特点,研究基于开放可编程的新一代路由器架构.介绍了控制和转发相分离的ForCES协议框架和Intel IXA结构,提出了一种基于网络处理器IXP2400并支持ForCES协议的开放可编程的路由器框架.详细地分析了转发件中Xscale层的设计和实现.在此基础上设计了相应的测试平台,实验结果表明了这种路由器框架的可行性.     

Power consumption analysis of a NetFPGA based router

For both economic and environmental reasons, energy efficiency is becoming increasingly important in the design of next generation networks (NGN). The energy efficiency improvements for network components can mainly be achieved by the support of smart standby and/or frequency scaling. This paper describes fine-grained power measurements of the peripheral component interconnect (PCI)-based network field-programmable gate array 1 gigabit (NetFPGA 1G) reference router when scaling the frequency of router core logic and static random access memories (SRAMs) between 125 MHz and 62.5 MHz. This paper presents the power consumption of a NetFPGA 1G reference router under different scenarios. Results show that by reducing the frequency from 125 MHz to 62.5 MHz, under a user datagram protocol (UDP) traffic load of 400 Mbit/s, 12.23% of power can be saved with the same quality of service (QoS), i.e. no packet loss in either case. Moreover, aggregating the traffic and rerouting the packets can save relatively high amount of energy. For example, our results show that 19.77% of power consumption can be saved by aggregating four 100 Mbit/s links into two 200 Mbit/s links.     

Demonstration of the highly reliable Hikari router network based on a newly developed disjoint path selection scheme

Integration of multiprotocol label switching functions and multiprotocol lambda switching functions can enhance the throughput of IP networks and remove bottlenecks that are derived from electrical packet processing. To enhance the packet forwarding capability, NTT proposed a photonic MPLS concept that includes MP/spl lambda/S, and demonstrated IP, MPLS, and photonic MPLS integrated router systems called the photonic MPLS router. This router system is now called the Hikari router. The word Hikari is Japanese meaning beam, light, lightwave, optical, photonic, and sunshine. The amount of IP data traffic has grown remarkably. Massive IP routers and flexible route control mechanisms are now required to cope with the increased amount of traffic. The Hikari router can offer two solutions utilizing photonic switching technologies, and photonic network operation and management technologies. The first solution is utilizing photonic switching technologies realized using optical-switch-based crossconnect systems. The other solution is realized using the MPLS and MP/spl lambda/S signaling protocol and photonic network protection functions. In this article we report on the implementation of the Hikari router systems, propose a newly developed disjoint path selection scheme for generalized MPLS networks with shared risk link group constraints, and demonstrate the signaling protocol and network protection functions. The demonstration system achieves a distributed optical path set-up/tear-down protocol with an extended constraint-based routing label distribution protocol. Fast self-healing through automatic protection switching and a new restoration scheme are also implemented. These functions are successfully implemented, and the performance is verified on a demonstration network. The protection switching scheme achieves protection in less than 20 ms, and the optical path restoration scheme achieves restoration in less than 500 ms.     

智能终端中热IP核的通信方法

片上网络通信架构的改进,使热IP核连接多个路由器,并且原本与热IP核相连的一个路由器的通信量被分配到多个路由器上。基于改进的片上网络通信架构,又设计出新的路由器选择算法。在该算法中,可以根据热IP连接的路由器的当前状态选择数据通信的路由,这样使得热IP能够更加均匀地分配通信量,从而有效地提高了数据传输效率,降低数据传输延时。实验表明,新的算法能够有效减少传输延迟。     

Multi‐topology routing based egress selection approach to achieve hybrid intra‐AS and inter‐AS traffic engineering

Hot‐potato routing is a border gateway protocol policy that selects the ‘closest’ egress router in terms of interior gateway protocol cost. This policy imposes inherent interactions between intra‐AS (Autonomous System) and inter‐AS traffic engineering. In light of this observation, we present a hybrid intra‐AS and inter‐AS traffic engineering scheme named egress selection based upon hot potato routing. This scheme involves link weight optimization, which can not only minimize the time that IP (Internet Protocol) packets travel across the network by assigning specified egress router but also balance the load among the internal links of the transit network. Egress selection based upon hot potato routing also incorporates multi‐topology routing technique to address the problem that one set of link weights might not guarantee specified egress routers. Accordingly, we formulate the link weights optimization problem using multi‐topology routing as a mixed integer linear programming model. And we present a new heuristic algorithm to make the problem tractable. Numerical results show that only a few topologies are needed to guarantee specified egress router, and maximum link utilization is also reduced. Copyright © 2014 John Wiley & Sons, Ltd.     

基于IPv4过渡时期NAT技术应用研究

当前网络IPv4协议逐渐被IPv6协议所取代,在此过渡时期,由于公网地址资源的紧缺,导致多种网络应用服务无法开展,迫切需要有新的解决办法来突破限制。针对当前IPv6技术仍处于未普及之时,通过在路由器上使用网络地址转换技术转换方案仍不失为最佳办法,尽管NAT本身仍存在许多弊端。