网络虚拟化的过去、现在和未来

网络虚拟化过程中主要诞生过4类过渡技术:虚拟局域网络(VLAN)、虚拟专用网络(VPN)、主动可编程网络(APN)、覆盖网络。网络虚拟化的研究现在主要集中于3个领域:云计算应用、平台化实现、软件定义网络。认为网络虚拟化的未来在性能保障、可靠性、易用性和完备性等方面需要加强,为此未来的网络虚拟化需要优化自身服务结构,并向无线网络、光网络等领域推广,此外还需要提供更加友好的可编程接口(API)以及网络功能。     

OECD:加强保险在网络风险管理中的作用

随着数字化经济的发展,网络风险问题受到越来越多国家的关注。对此,经济合作与发展组织(OECD)发布研究报告《加强保险在网络风险管理中的作用》,指出网络风险保险日趋重要,其通过促进对网络损失风险的认识,分享风险管理的专业知识,鼓励投资以降低风险和促进网络事件响应,对管理网络风险做出重要的贡献。其中,报告重点介绍了日益增长的网络风险、市场上网络风险的范围和损失类型的多样性及网络保险市场面临的挑战。最后,分别针对网络保险保障端(政府)、网络保险供给端(保险公司)和网络保险需求端(机构)提出十条建议对策,希望可以给网络保险的发展做出贡献。     

无人船网络信息安全技术综述

随着智能航运时代的到来，世界各国都在积极推动无人船的研发工作。与此同时，无人船所面临的网络信息安全问题逐渐显露，已经成为阻碍行业发展的重大挑战之一。围绕信息安全问题，介绍了无人船发展现状以及网络组成，重点阐述无人船网络安全威胁。从身份认证技术、入侵检测技术、信息加密技术以及无人船位置信息保密技术四个方面对无人船网络信息安全相关的网络攻击对策进行综述，最后对前沿技术在未来无人船网络信息安全中的应用进行了展望和总结。     

局部网络概观

局部网络是由地理位置比较密切(在一幢或若干幢建筑内)的终端、主机和其它设备所组成的一种网络。局部网络在某种程度上既具有多处理机系统的性质又具有远距离数据网络的性质。其重要特征为: ·数据传输率高(0.1—100兆位/秒) ·距离短(0.1—50公里) ·误码率低(10~(-8)—10~(-11)) 局部网络的出现将给系统带来许多好处。其中最重要的好处是:在一个设计良好的网络中,局部网络支持系统的形成和扩充,能够增加或替换设备,而对网络中其它设备几乎不会     

网络功能虚拟化弹性和可扩展性研究

在NFV(网络功能虚拟化)过程中,将PNF(物理网络功能)转换为VNF(虚拟化网络功能)会面临诸多挑战。VNF(虚拟化网络功能)支持网络服务的按需部署和弹性增长,助力提升NFV的弹性和可扩展性。文章介绍主机VNF(虚拟化网络功能)和中间盒VNF两种类型,探讨多路径和分布式VNF设计思路,列举与VNF弹性设计相关的v PE(虚拟提供商边缘)实例,阐述NFV和SDN(软件定义网络)之间的关系。     

下一代光通信网络传送技术概述及其趋势

通过研究新一代传送网络技术,分析新一代传送网络市场和技术发展状况,介绍了新一代传送网络推动的软件定义网络(SDN)技术以及网络功能虚拟化(NFV)架构等新技术,指出随着新一代传送技术的发展,下一代光通信网络传送技术的趋势必然是高容量高动态的全光网络。     

六维分析法提升农村TD-LTE网络质量

农村区域特别是偏远农村地区LTE网络尚未能有效连续覆盖,导致LTE客户感知存在较多问题,文章对此提出一种科学、高效的面向农村客户感知的评估优化方法,通过网络优化手段,主动提升网络质量。采用包含网络覆盖、网络结构、网络干扰、网络容量、网络性能、CSFB(电路域回落)感知的基于客户感知的LTE(长期演进)六维分析法,分析网络短板,制定可行的网络优化手段,提升网络质量。     

SURPASS--西门子下一代网络解决方案

SURPASS方案是西门子针对未来网络发展提出的基于软交换机制的宽带电信级网络解决方案,方案基于面向NGN(下一代网络)的分布式网络结构。SURPASS完整的解决方案可分别从接入、核心、业务和支撑网络等多种网络角度提供全面的网络方案;可针对不同类型的运营商(CLEC、ILEC)的网络环     

固移网络边界网关虚拟化融合研究

固定/移动网络融合(Fixed-mobile Convergence,FMC)是未来网络演进的重要发展趋势。文章首先对固移网关边界网关功能进行介绍,分析边界网关融合面临的挑战。针对当前融合面临的挑战,利用SDN(Software Defined Networking)与网络功能虚拟化的思想,提出固移网络虚拟化融合解决方案,为运营商未来实现固移网络融合、简化网络结构、降低网络投资运营成本提供了理论指导。     

软件定义网络安全框架研究

SDN(软件定义网络)安全架构涉及到多种安全支撑技术或安全层,包括云安全、网络和应用安全以及ONAP(开放式网络自动化平台)安全。文章给出AIC(AT&T集成云)安全框架,介绍通过服务将安全组件链接到VNF(虚拟化网络功能)OAM(运营、管理和维护)路径的安全功能,列举MPLS(多协议标签交换)VPN(虚拟专用网)设计中应遵循的基本原则,考虑两种可能对SDN控制器安全构成威胁的情形,说明ONAP平台和接口,描述VNF安全需求评估的内容。     

Congestion Control Performance of R-DSDV Protocol in Multihop Wireless Ad Hoc Networks

Ad hoc wireless networks are composed of mobile nodes communicating through wireless links, without any fixed backbone infrastructure. Frequent topology changes due to node mobility make routing in such dynamic networks a challenging problem. Moreover, successful message routing implies every mobile node is potentially capable of acting as a router, thus supporting store-and-forward mechanisms. However, resource limitations on these nodes also require a control on congestion due to message forwarding. In this paper, we consider our recently proposed randomized version of the well-known Destination-Sequenced Distance Vector (DSDV) routing protocol, referred to as R-DSDV, and validate its performance through extensive simulation experiments. Our results demonstrate that a probabilistic control on message traffic based on local tuning of protocol parameters is feasible, and that R-DSDV outperforms the basic DSDV protocol by significantly reducing the average queue size associated with each mobile node and hence the average packet delay.     

一种能量平衡的无线体域网络AODV多播路由发现协议

在动态网络拓扑中,AODV协议通过数据源节点S泛洪广播RREQ消息请求到任意目标节点D的路由,而在无线体域网络中,只有一个sink目标节点,除最短跳数路由上的节点外,其他参与RREQ接收和转发的节点浪费了能量。提出了一种能量平衡的无线体域网络AODV多播路由发现协议,通过在节点广播的hello消息中增加到sink的最小跳数hops、到sink的下一跳节点next和节点本身是否具备转发能力isforward 3 个参数,只选择能到达sink节点的邻居节点参与转发RREQ消息,变广播为多播,有效地降低了路由发现的能量开销,并通过能量平衡延长了WBAN的使用寿命。性能分析与模拟实验表明,该协议在RREQ数量、数据传输率和能量消耗等方面优于相似协议EAAODV。     

A delay‐bounded routing protocol for vehicular ad hoc networks with traffic lights

In vehicular ad hoc networks, vehicles may use a routing protocol to inform emergent events, for example, car accidents or traffic jams. Hence, many of the researchers are focused on minimizing the end‐to‐end delay of the routing protocol. However, some applications, for example, email or ftp, are not time critical, and radio spectrum is a limited resource. Hence, delay‐bounded routing protocol, whose goal is to deliver messages to the destination within user‐defined delay and minimize the usage of radio, has become an important issue. The delay‐bounded routing protocols deliver message to the destination by the hybrid of data muling (carried by the vehicle) and forwarding (transmitted through radio). When the available time is enough, the message will be delivered by muling; otherwise, it will be delivered by forwarding. However, in an urban area, there are many traffic lights, which may greatly affect the performance of the delay‐bounded routing protocols. Existing works do not consider the effect of traffic lights, and hence, it may adopt an improper delivery strategy and thus wastes much available time. To improve previous works, we propose a novel delay‐bounded routing protocol, which has considered the effect of traffic lights. Whenever a vehicle passes an intersection, it will gather the information of the traffic light and traffic load of the next road section, and thus, it can make a more accurate prediction and adopt a more proper strategy to deliver message. Simulation results show that the proposed protocol can make a better usage of the available time and uses less radio resource to deliver the message in time. Copyright © 2013 John Wiley & Sons, Ltd.     

多层卫星网络链路中断容忍路由策略设计

链路中断和接续对卫星网络路由有重要影响,该文针对多层卫星网络,设计了链路中断容忍路由策略,利用非均匀时间段内卫星网络拓扑结构的可预测性进行路由表计算,采取动态的拥塞控制机制和洪泛策略,解决由于卫星运动、通信设备故障引发链路中断情况下的路由问题。仿真结果表明,该路由策略具有较高的链路利用率,能够减少动态路由计算中时延信息收集和星上路由表生成给卫星节点带来的时空开销。     

基于拥塞预知的WSN多径寻优路由协议

针对无线传感器网络中常出现传输拥塞的问题,该文提出了一种基于拥塞预知的多径寻优路由协议(MOPC)。该协议基于主动避免拥塞的设计思想,依据节点的拥塞预知度、剩余能量和最小跳数建立路径满意度模型,实现了最优路径的选取;通过设定最优路径上节点的转发满意度变化率阈值,实现局部路由的动态维护。仿真结果表明,该协议具有良好的实时性和可靠性,并能显著提高能量利用率,延长网络生命期。     

HVE-mobicast: a hierarchical-variant-egg-based mobicast routing protocol for wireless sensornets

In this paper, we propose a new mobicast routing protocol, called the HVE-mobicast (hierarchical-variant-egg-based mobicast) routing protocol, in wireless sensor networks (WSNs). Existing protocols for a spatiotemporal variant of the multicast protocol called a “mobicast” were designed to support a forwarding zone that moves at a constant velocity, \(\stackrel{\rightarrow}{v}\), through sensornets. The spatiotemporal characteristic of a mobicast is to forward a mobicast message to all sensor nodes that are present at time t in some geographic zone (called the forwarding zone) Z, where both the location and shape of the forwarding zone are a function of time over some interval (t _start ,t _end ). Mobicast routing protocol aims to provide reliable and just-in-time message delivery for a mobile sink node. To consider the mobile entity with the different moving speed, a new mobicast routing protocol is investigated in this work by utilizing the cluster-based approach. The message delivery of nodes in the forwarding zone of the HVE-mobicast routing protocol is transmitted by two phases; cluster-to-cluster and cluster-to-node phases. In the cluster-to-cluster phase, the cluster-head and relay nodes are distributively notified to wake them up. In the cluster-to-node phase, all member nodes are then notified to wake up by cluster-head nodes according to the estimated arrival time of the delivery zone. The key contribution of the HVE-mobicast routing protocol is that it is more power efficient than existing mobicast routing protocols, especially by considering different moving speeds and directions. Finally, simulation results illustrate performance enhancements in message overhead, power consumption, needlessly woken-up nodes, and successful woken-up ratio, compared to existing mobicast routing protocols.     

无线自组织网络中一种拥塞意识的多径路由算法

提出了无线自组织网络中一种拥塞意识的多径路由算法。该算法在路由发现过程中,综合节点的队列长度和路径跳数来动态确定路由请求消息的转发概率,可以在保证路由请求消息有一定送达率的条件下,降低路由开销;在路径选择和流量分配过程中,综合考虑节点的队列长度和路径质量作为路由度量,发现流量高吞吐量低拥塞路径,并基于该度量值进行流量分配。仿真结果显示,所提出的多径路由算法能有效提高网络性能。     

Boundary Mapping and Boundary-State Routing (BSR) in Ad Hoc Networks

This paper presents a geographic routing protocol, boundary state routing (BSR), which consists of two components. The first is an improved forwarding strategy, greedy-bounded compass, which can forward packets around concave boundaries, where the packet moves away from the destination without looping. The second component is a boundary mapping protocol (BMP), which is used to maintain link state information for boundaries containing concave vertices. The proposed forwarding strategy greedy-bounded compass is shown to produce a higher rate of path completion than Greedy forwarding and significantly improves the performance of greedy perimeter state routing (GPSR) in sparse networks when used in place of greedy forwarding. The proposed geographic routing protocol BSR is shown to produce significant improvements in performance in comparison to GPSR in sparse networks due to informed decisions regarding the direction of boundary traversal at local minima.     

一种基于区域广播的VANET机会路由协议

对VANET网络中现有的路由协议进行了系统的分析和研究,提出了一种基于区域广播的VANET机会路由协议。基于安全消息在网络割裂情况下的传播需求,新协议结合地理信息和机会转发算法,提出了不同于点对点的新的基于区域广播的消息传播模式,以实现安全消息在稀疏车辆环境下的有效传播。理论分析和仿真实验表明,该协议相比传统路由协议具有更优异的网络性能和可靠性。     

Early detection and rejection probability‐based congestion control scheme for deep space networks

Deep Space Networks (DSNs) are a class of DTNs. In such networks, owing to limited radio range and node mobility, end‐to‐end paths between source and destination nodes are not available. Messages are relayed by store‐and‐forward strategy and may be buffered for long periods before being forwarded to the next hop. Therefore, the buffer of message carriers may overflow, and congestion follows. To address this issue, this paper proposes an early detection and rejection probability‐based congestion control algorithm, named ERBA, in which every intermediate node estimates rejection probability when a new message arrives and refuses to receive the message with the rejection probability, so as to avoid congestion. To validate its effectiveness, ERBA is merged into static routing (SR) and dynamic routing (DR). SR and DR are classical routing algorithms for DSNs. The simulation results show that when working with ERBA, the routing overhead of SR and DR decreases rapidly. However, the message delivery ratio also decreases. To deal with this problem, we propose a buffer‐compensation mechanism that effectively reduces the routing overhead for SR and DR without causing the reduction of the message delivery ratio.Copyright © 2014 John Wiley & Sons, Ltd.