智能光网络的路由架构及实现方案

本文对智能光网络路由架构中的路由控制器、链路资源管理器、协议控制器和路由信息数据库的功能进行了介绍，对分发路由信息过程中所使用的路由属性及路由消息作了描述，最后给出了基于GMPLS的智能光网络控制平面的实现方案。     

自动交换光网络路由技术

主要讨论自动交换光网络（ASON）中的路由技术。首先介绍了ITU－T关于ASON路由技术体系结构的要求，然后讨论了ASON路由技术与IP网络路由的不同之处，接着分析了IETF GMPLS对IP路由协议的扩展，包括OSPE－TE和ISI－TE。最后介绍了光互连论坛（OIF）在网络－网络接口（NNI）路由协议方面的进展情况。     

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。     

智能光网络的路由架构及实现方案

本文对智能光网络路由架构中的路由控制器、链路资源管理器、协议控制器和路由信息数据库的功能进行了介绍 ,对分发路由信息过程中所使用的路由属性及路由消息作了描述 ,最后给出了基于 GMPL S的智能光网络控制平面的实现方案     

无线传感器网络路由问题探讨

无线传感器网络（WSN）具有与传统网络显著不同的特点，导致应用于传统网络的路由协议并不适用于无线传感器网络，因此有必要研究新的路由协议为之服务。文中在介绍WSN的特点后，将着重讨论其路由过程并把整个过程分为路由建立和路由更新两个阶段，通过对当前应用较多的路由协议分析，对每个阶段进行阐述；文章最后对WSN路由协议未来的研究策略与发展趋势提出了一些具体研究意见。     

智能OXC在ASON中的应用

IP与光技术的融合要求底层光网络具有高度的灵活性和可扩展性，产生了全新的ASON（自动交换光网络），智能OXC（光交叉连接）设备是ASON中的最关键的设备。文中简单介绍了智能自动交换光网络的概念、网络结构，详细分析了ASON中智能OXC矩阵硬件结构和OXC控制平面信令路由功能，最后讨论了智能OXC相关协议及扩展的GMPLS技术。智能OXC强大的光交换能力结合智能信息路由协议，必将与现有网络融合向全智能光网络发展。     

移动Ad hoc网络中基于链路稳定性预测的按需路由协议

移动Ad hoc网络拓扑的高度动态变化是造成传统按需路由协议的路由频繁通断的主要原因,因此在传统按需路由协议的基础上进行链路稳定性预测扩展,增强路由稳定性具有十分重要的意义。该文利用分组的接收功率把节点间的相对运动划分为靠近和远离两种类型,然后在不同相对运动类型下根据节点间距离得到了的链路平均维持时间。在路由过程中,中间节点利用得到的链路平均维持时间设置请求报文的转发延迟,通过一定转发规则选择稳定性较强的链路构成路径。仿真结果表明进行链路稳定性预测扩展后的按需路由协议能够有效增强路由的稳定性,并提高网络性能。     

灵活透明光网络的自适应传输控制策略

灵活透明光网络是传送网的发展演进方向之一。目前,智能传送网的协议标准主要用于选路与交换过程的控制,若在自动交换光网络(ASON)架构基础上引入对传送平面物理特性的智能控制功能,基于损伤感知对控制平面进行功能扩展,可以实现端到端传输质量最优化。传输自适应的控制过程可以用可调节补偿单元信息搜集、链路传输性能监测、自适应调节计算、可调节补偿单元控制等4个步骤来实现。支持光通路自适应传输过程的协议扩展可采用分布式路由方案和分布式信令方案两种解决方案。     

下一代光网络ASON中的控制组件

文章主要阐述了作为下一代光网络的自动交换光网络控制平面的基本功能,以及实现这些功能所需要的控制组件,并对几个主要控制组件的功能和接口作了描述,同时简单介绍了控制平面中信令、路由和链路管理所采用的相关协议。     

一种基于ASON的新型动态恢复路径建链协议

讨论了动态波长路由光网络的恢复路径提供问题，在联合可变权重路由选择(JVWR)算法的基础上重点对恢复路径建立时延进行了分析，通过对恢复路径建立过程中的非物理资源相关因素的考虑，基于ASON控制平面的分布式信令协议提出了前向并行建链协议(FPLSP)。理论分析和仿真实验表明，该建链协议对于减少恢复路径链路建立时延具有明显的效果。     

An Ad Hoc Routing Protocol with Multiple Backup Routes

Numerous routing protocols have recently been developed for ad hoc mobile networks. Routing protocols to date can be categorized as either ‘table-driven’ or ‘on-demand’. Many of the proposed routing protocols take the on-demand approach because this does not require keeping lots of routing information. However, these kinds of protocols are not able to react fast enough to maintain routing. In this paper, we propose a new protocol to improve existing on-demand routing protocols by constructing multiple backup routes; when the network topology changed, the proposed protocol could transmit data packets dynamically through backup routes. We then developed an analytic model to estimate the reconnection probability of the proposed algorithm. We also examined the performance by simulating the protocol using ns2. The experimental results showed that the protocol had fewer control packages, lower routing packet overhead, and a higher receiving ratio than others.     

基于GMPLS的OBS网络技术

GMPLS(通用多协议标签交换)是MPLS技术向光网络发展的产物。描述GMPLS和MPLS控制平台的区别,介绍引用GMPLS协议作为控制平面的OBS网络。提出的网络结构是在OBS的突发控制包中用通用标签代替源节点和目的节点地址,并使用GMPLS协议栈对路由协议、信令功能以及链路管理协议进行增强和扩展以便更好地支持OBS网络。     

FIRE: flexible intra-AS routing environment

Current routing protocols are monolithic, specifying the algorithm used to construct forwarding tables, the metric used by the algorithm (generally some form of hop count), and the protocol used to distribute these metrics as an integrated package. The flexible intra-AS routing environment (FIRE) is a link-state, intradomain routing protocol that decouples these components. FIRE supports run-time-programmable algorithms and metrics over a secure link-state distribution protocol. By allowing the network operator to dynamically reprogram both the properties being advertised and the routing algorithms used to construct forwarding tables, FIRE enables the development and deployment of novel routing algorithms without the need for a new protocol to distribute state. FIRE supports multiple concurrent routing algorithms and metrics, each constructing separate forwarding tables. By using operator-specified packet filters, separate classes of traffic may be routed using completely different routing algorithms, all supported by a single routing protocol. This paper presents an overview of FIRE, focusing particularly on FIRE's novel aspects with respect to traditional routing protocols. We consider deploying several current unicast and multicast routing algorithms in FIRE, and describe our Java-based implementation     

A Review on Hierarchical Routing Protocols for Wireless Sensor Networks

The routing protocol for Wireless Sensor Networks (WSNs) is defined as the manner of data dissemination from the network field (source) to the base station (destination). Based on the network topology, there are two types of routing protocols in WSNs, they are namely flat routing protocols and hierarchical routing protocols. Hierarchical routing protocols (HRPs) are more energy efficient and scalable compared to flat routing protocols. This paper discusses how topology management and network application influence the performance of cluster-based and chain-based hierarchical networks. It reviews the basic features of sensor connectivity issues such as power control in topology set-up, sleep/idle pairing and data transmission control that are used in five common HRPs, and it also examines their impact on the protocol performance. A good picture of their respective performances give an indication how network applications, i.e whether reactive or proactive, and topology management i.e. whether centralized or distributed would determine the network performance. Finally, from the ensuring discussion, it is shown that the chain-based HRPs guarantee a longer network lifetime compared to cluster-based HRPs by three to five times.     

基于ZigBee的无线传感器网络路由分析

为了研究基于ZigBee的无线传感器网络路由协议的性能优劣,在路由设计中有选择地改进。介绍了ZigBee无线传感器网络结构,分析了AODV、LEACH和ZigBee路由三种路由协议的基本原理,并使用NS2模拟仿真软件,在其他外部条件相同的情况下,分别对ZigBee路由和AODV进行模拟仿真,以能量消耗和网络生命周期为衡量网络性能的指标,仿真结果表明ZigBee路由在能耗上高于AODV,算法在节能上有待改进。指出了ZigBee路由算法在节能上的改进方法。     

Recent developments in securing Internet routing protocols

Routing protocols distribute network topology information around the routers of a network. They are part of the critical network infrastructure, but are vulnerable to both internal and external attacks. In this paper, different routing protocols are first introduced, followed by reviews of routing protocol security publications in academia and industry. The general vulnerabilities and threats of routing protocols are then analysed. The two major protection countermeasures for both link-state routing protocols and distance-vector routing protocols are presented in detail. The popular hacking tools which can be used directly or customised to launch attacks are described. The product vendors of routing protocol security and the best practice adopted by network carriers and ISPs are investigated. The paper aims to provide an overview of Internet routing protocol security, and highlight areas for further research.     

Information Theoretic Analysis of Proactive Routing Overhead in Mobile Ad Hoc Networks

This paper considers basic bounds on the overhead of link-state protocols in mobile ad hoc networks. Hierarchical protocols are known for their good scalability properties, and hence this paper considers a two-level hierarchical protocol. In such protocols, nodes need to keep track of shortest path information, link states and cluster membership. Two types of overheads are considered; the memory needed to store routing-related information, including link-states and cluster membership, and the control messages that need to be exchanged to keep track of the changes in the network. Memory overhead is important practically for dimensioning network nodes, while message routing overhead is important since it reduces the effective capacity of the network to carry user data (vis-a-vis control data). The scalability properties of the message routing overhead are analyzed for different modes of network scaling. Practical implications, such as optimal cluster size, average/fixed memory requirement and routing protocol parameter selections are discussed.     

A simulation study of table-driven and on-demand routing protocolsfor mobile ad hoc networks

Bandwidth and power constraints are the main concerns in current wireless networks because multihop ad hoc mobile wireless networks rely on each node in the network to act as a router and packet forwarder. This dependency places bandwidth, power, and computation demands on mobile hosts which must be taken into account when choosing the best routing protocol. In previous years, protocols that build routes based on demand have been proposed. The major goal of on-demand routing protocols is to minimize control traffic overhead. We perform a simulation and performance study on some routing protocols for ad hoc networks. The distributed Bellman-Ford (1957, 1962), a traditional table-driven routing algorithm, is simulated to evaluate its performance in multihop wireless network. In addition, two on-demand routing protocols (dynamic source routing and associativity-based routing) with distinctive route selection algorithms are simulated in a common environment to quantitatively measure and contrast their performance. The final selection of an appropriate protocol will depend on a variety of factors, which are discussed in this article     

Scalability enhancement of AODV using local link repairing

Dynamic change in the topology of an ad hoc network makes it difficult to design an efficient routing protocol. Scalability of an ad hoc network is also one of the important criteria of research in this field. Most of the research works in ad hoc network focus on routing and medium access protocols and produce simulation results for limited-size networks. Ad hoc on-demand distance vector (AODV) is one of the best reactive routing protocols. In this article, modified routing protocols based on local link repairing of AODV are proposed. Method of finding alternate routes for next-to-next node is proposed in case of link failure. These protocols are beacon-less, means periodic hello message is removed from the basic AODV to improve scalability. Few control packet formats have been changed to accommodate suggested modification. Proposed protocols are simulated to investigate scalability performance and compared with basic AODV protocol. This also proves that local link repairing of proposed protocol improves scalability of the network. From simulation results, it is clear that scalability performance of routing protocol is improved because of link repairing method. We have tested protocols for different terrain area with approximate constant node densities and different traffic load.     

Duty cycle allocation to maximize network lifetime of wireless sensor networks with delay constraints

In wireless sensor networks, the routing control overhead could be large because multiple relays are involved in the routing operation. In order to mitigate this problem, a promising solution is to use tier‐based anycast protocols. The main shortcoming of these protocols is that they can consume a much greater amount of energy as compared with other competing protocols using deterministic routing. In this paper, we analyze, in depth, a tier‐based anycast protocol and develop a new technique of improving network lifetime. Our solution is guided by our analytic framework that consists of subtiering and a new forwarding protocol called ‘scheduling controlled anycast protocol’. We formulate the problem for finding an optimal duty cycle for each tier with a delay constraint as a minimax optimization problem and find its solution, which we show is unique. From the analytical results, we find that the network lifetime can be significantly extended by allocating a different duty cycle adaptively for each tier under a delay constraint. Through simulations, we verify that our duty cycle control algorithm enhances the network lifetime by approximately 70% in comparison with an optimal homogeneous duty cycle allocation. Copyright © 2012 John Wiley & Sons, Ltd.