互联网路由可扩展问题探讨

随着Internet网络的迅猛发展,传统互联网架构面临着严峻挑战,尤其是路由可扩展问题。本文阐述了互联网路由可扩展问题的背景,分析了导致路由系统可扩展性问题的内在原因和外部原因,在此基础上讨论了设计新型网络架构时所需要满足的要求,并对目前主要的技术策略及思路,以及几个重要解决方案进行了分析与对比。     

基于位置无关名字的可扩展几何路由方案

名字路由已成为未来网络的研究热点之一,由于网络中节点和信息规模的持续增长,可扩展问题成为其瓶颈.几何路由作为新型可扩展路由方案,可同时满足路由表规模和路由路径的可扩展,但难以支持名字路由.首先在几何路由基础上提出了一种通用的基于位置无关名字的可扩展几何路由方案——GRIN,结合源路由和贪心路由实现混合几何路由,在混合几何路由上引入基于双层稀疏群组的名字解析(映射).然后理论分析了节点状态及名字映射的路径延展度上界.最后通过仿真验证了GRIN具备可扩展、低延展度以及高可靠性等特征,并优于其他名字路由方案.     

可信路由机理及关键技术

文章认为由于网络规模的增大以及节点移动、多宿主、网络流量工程等需求的不断增强,使得路由可扩展性、安全性、可靠性等问题凸显。尽管与可信路由相对应的理论技术方案不断提出,但未能从根本上解决网络路由的可信任问题。为此文章提出可信路由体系结构模型、可信域内路由、可信域间路由等新网络环境下的可信路由参考机制,并对可信路由涉及的关键技术,如映射可扩展技术、路由信任机制、多径路由技术、服务质量保证、路由监测管理技术,进行了研究和探讨。     

基于APG合并及拓扑势优化的启发式用户关联策略

针对去蜂窝网络的可扩展问题,定义了网络可扩展度作为性能衡量指标,设计了一种提高网络可扩展度的用户关联策略。该策略以网络耦合度最小和用户速率最大为优化目标。为了进一步降低求解该多目标优化问题的复杂度,通过利用拓扑势函数建立网络耦合度和用户速率的关系,提出了基于接入点簇（APG）合并及拓扑势优化的启发式算法。仿真结果表明,所提策略以较小的用户速率损失为代价提高了去蜂窝网络的可扩展度。与传统策略相比,用户速率损失4.43%时,可扩展度可提高9.59%;与文献[10]的策略相比,用户速率损失4.99%时,可扩展度可提高22.15%。     

一种基于推荐网络的拒绝服务攻击检测发现方法

在开放、动态的环境中,如何区分正常与异常数据已经成为互联网的难点和关键问题。针对在推荐网络中没有考虑数据来源的可信度问题,提出了一种基于推荐网络信任模型的路由算法。构建了一个推荐网络信任模型,并给出了相关策略。数据在路由的过程中,根据策略决定数据的路由概率,从而迅速降低恶意数据的传播。     

基于网络拓扑的分布式可扩展对等网模型设计

针对当前主流P2P路由模型存在的缺陷和不足,提出一种基于网络拓扑的分布式可扩展的对等网络模型,该模型设计以Gnutella,Napster和Chord子网为研究对象,提出综合路由维护机制,对普通节点和边缘节点采用不同路由策略,在节点加入退出机制以及路由维护策略中,新模型既降低网络的负载又提高了网络的可用性,仿真测试表明新型网络模型的平均时延和查询跳数均比chord网络模型低.     

基于DHT的对等网络路由定位模型研究

分布式哈希表[1](Distributed Hash Table,DHT)是一种非常有前景的对等网络拓扑模型。介绍了目前最流行的3种P2P网络模型,其中重点描述了具有自组织、可扩展、负载均衡,以及较好的容错性的结构化对等网络模型。通过分析基于DHT的CAN,Chord,Tapestry,Pastry的4种结构对等网系统的路由定位模型,比较并总结出4种网络不同的路由定位策略、路由性能、路由效率及各自的特点。     

基于LSRR选项的可扩展IPv4网络

考虑到互联网快速膨胀发展以及3G、IMS的大规模部署的需要，本文提出了一种现行IP网络可扩展的实现方法，采用公有域和局部域的两级可扩展IP网络架构。根据源IP节点与目的IP节点的位置表示，基于源路由的方式控制IP数据包无障碍的穿行于整个可扩展IP网络。该方案采用既有的互联网标准按需扩展，不必改造现有网络，没有升级过渡问题。     

一种面向智慧协同网络的自适配路由策略研究

现有互联网网络体系和机制相对"静态"和"僵化",缺乏支持智慧网络的有效机制.要从根本上解决现有互联网存在的严重弊端,必须创建新的网络理论体系.本文在智慧协同网络"三层"、"两域"体系结构下,针对"网络组件层"的路由自适配问题展开研究,提出基于生物启发的转发网络族群自适配路由策略,实现族群内路由组件之间的智慧协调、动态重构和优化决策,有效解决现有路由策略的静态、僵化等问题.通过数学分析证明:如果设定模型参数μ∈(0,1),提出的自适配路由策略可以始终保持稳定性.最后,通过原型系统验证了提出自适配路由策略是切实可行的,能够提高网络的承载业务数量和提升用户体验.     

新互联网体系理论及关键技术

互联网在可信(安全、可靠、可控、可管)等方面存在严重弊端。为解决这些问题,文章研究和探索新一代互联网体系的基础理论,给出了新网络的体系结构模型;创造性地提出新网络体系下的交换路由模型与理论,建立接入标识、广义交换路由标识及其映射理论;提出普适服务体系模型与理论,创建服务标识及其映射理论、连接标识及其映射理论;并对新互联网体系中的接入控制管理、可信路由及服务质量、多流传输、网络监测管理等关键技术进行了研究和探讨。     

Emulation platform for inter-domain protocols validation of integrated space-terrestrial network

The inter-domain routing protocol is a key factor in the rapid integration of various satellite systems and heterogeneous networks in integrated space-terrestrial network (ISTN).However,the wide difference between network topologies of space and terrestrial networks may present significant challenges to the deployment of existing inter-domain protocols.To test the performance of these protocols,an emulation platform for ISTN was designed to efficiently emulate the dynamic and large-scale space network and the existing terrestrial networks using virtual network technology.Extensive experiments demonstrate that,with the expansion of the scale of space network and the scale of terrestrial Internet’s routing table,the integration efficiency between space and terrestrial networks becomes very low.     

实际网络的复杂特征分析

随着对复杂网络的深入研究,现实生活中越来越多的网络被证明具有复杂网络的特性,如小世界特性,无标度特性和高聚类系数等.本文介绍了九种现实网络所具有的复杂网络特性,并介绍了权重网络和空间网络的基本概念,它们更多的考虑了现实网络的特性,并能更好的模拟实际网络.     

Safari: A self-organizing, hierarchical architecture for scalable ad hoc networking

As wireless devices become more pervasive, mobile ad hoc networks are gaining importance, motivating the development of highly scalable ad hoc networking techniques. In this paper, we give an overview of the Safari architecture for highly scalable ad hoc network routing, and we present the design and evaluation of a specific realization of the Safari architecture, which we call Masai. We focus in this work on the scalability of learning and maintaining the routing state necessary for a large ad hoc network. The Safari architecture provides scalable ad hoc network routing, the seamless integration of infrastructure networks when and where they are available, and the support of self-organizing, decentralized network applications. Safari’s architecture is based on (1) a self-organizing network hierarchy that recursively groups participating nodes into an adaptive, locality-based hierarchy of cells; (2) a routing protocol that uses a hybrid of proactive and reactive routing information in the cells and scales to much larger numbers of nodes than previous ad hoc network routing protocols; and (3) a distributed hash table grounded in the network hierarchy, which supports decentralized network services on top of Safari. We evaluate the Masai realization of the Safari architecture through analysis and simulations, under varying network sizes, fraction of mobile nodes, and offered traffic loads. Compared to both the DSR and the L+ routing protocols, our results show that the Masai realization of the Safari architecture is significantly more scalable, with much higher packet delivery ratio and lower overhead.     

基于可延展带宽分配的卫星网络高可用性方案

随着IPTV等网络服务的蓬勃发展,以及地面互联网的接入与融合,针对空间信息网络的资源规划势在必行.同时,为了有效抵抗分布式拒绝服务(DDoS)攻击,可用性设计成为卫星正常运转的重要前提.提出了基于网络带宽资源分配的DDoS攻击防御体系,建立了有效的卫星网络拓扑结构模型,并引入了路由状态数据包的概念,设计了相应的卫星网络路由协议.在此基础上,阐述了具有延展性的网络带宽分配机理及其实现方式.根据安全性分析与实验评估结果,提出方案可在有效防范敌手攻击的同时,保障带宽资源的可延展分配,同时方案具备良好的实现性能.     

Scalable peer-to-peer resource discovering scheme for wireless self-organized networks

Peer-to-peer technologies have attracted increasing research attention with fruitful protocols and applications proposed for wired networks. As to mobile environments, there are currently no mature deployments. A novel resource managing and discovering protocol, Cheer, is proposed to realize scalable and effective peer-to-peer lookup in wireless self-organized networks. Cheer resolves the topologies mismatch problem between peer-to-peer overlay networks and actual nodes distribution, allowing for frequent nodes membership changes. With specially designed resource storage table, Cheer also supports multikey and fuzzy lookup. Its hybrid architecture and improved routing scheme based on small-world theory may realize effective lookup routing. Theoretical analysis and simulation results both prove that Cheer makes using peer-to-peer applications in large-scale self-organized mobile networks feasible and promising.     

An architecture for IP over WDM using time-division switching

This paper proposes an architecture for routing Internet protocol (IP) packets directly on optical networks. The use of label switching is assumed in the IP routers, while a new routing architecture is introduced to transport IP packets across an optical backbone network. The architecture is based on a two-tier multiplexing approach with wavelength division multiplexing (WDM) addressing the number of regional exchanges and time-division switching communicating among the hubs. Such an architecture not only has the advantages of simple network management and high efficiency with low latency; it also is scalable by addition of regional exchanges, hubs, and fibers     

A novel Topology Aggregation approach for shared protection in multi-domain networks

Routing for shared protection in multi-domain networks is more difficult than that in single-domain networks because of the scalability requirements. We propose a novel approach for shared protection routing in multi-domain networks where the key feature is a special Topology Aggregation. In this Topology Aggregation, only some potential intra-domain paths (intra-paths for short) are selected for carrying working and backup traffic between domain border nodes. The abstraction of each intra-path to a virtual edge makes the original multi-domain network to become an aggregated network. On the aggregated network, a single-domain routing algorithm for shared protection can be applied for obtaining the complete routing solutions. The experiments show that the proposed approach is scalable. Moreover it is close to the optimal solution in single-domain networks and outperforms the previously proposed scalable solutions in multi-domain networks.     

Scalable domain partitioning in Internet OSPF routing

This paper addresses the scalability problem arising from rapidly increasing routing overhead at network expansion. Focusing on the OSPF (Open Shortest Path First) protocol, we propose a hierarchical routing scheme of partitioning a routing domain into areas. Supplemented to the scheme is a step to reinforce system performances, particularly reliability, against possible degradation from domain partitioning. For an Internet service provider with its own domain, the framework provides a practical vehicle for scalable hierarchical routing indispensable to overall service quality. Due to the unavailability of similar studies, a simple experiment with a small network is reported on, in place of extensive comparative testing. This revised version was published online in June 2006 with corrections to the Cover Date.     

Analysis of tree‐based multicast routing in wireless sensor networks with varying network metrics

Wireless ad hoc and sensor networks are emerging with advances in electronic device technology, wireless communications and mobile computing with flexible and adaptable features. Routing protocols act as an interface between the lower and higher layers of the network protocol stack. Depending on the size of target nodes, routing techniques are classified into unicast, multicast and broadcast protocols. In this article, we give analysis and performance evaluation of tree‐based multicast routing in wireless sensor networks with varying network metrics. Geographic multicast routing (GMR) and its variations are used extensively in sensor networks. Multicast routing protocols considered in the analytical model are GMR, distributed GMR, demand scalable GMR, hierarchical GMR, destination clustering GMR and sink‐initiated GMR. Simulations are given with comparative analysis based on varying network metrics such as multicast group size, number of sink nodes, average multicast latency, number of clusters, packet delivery ratio, energy cost ratio and link failure rate. Analytical results indicate that wireless sensor network multicast routing protocols operate on the node structure (such as hierarchical, clustered, distributed, dense and sparse networks) and application specific parameters. Simulations indicate that hierarchical GMR is used for generic multicast applications and that destination clustering GMR and demand scalable GMR are used for distributed multicast applications. Copyright © 2012 John Wiley & Sons, Ltd.     

On the design of self-organized cellular wireless networks

It has been observed that complex networks such as the Internet, World Wide Web, social networks, and biological systems are self-organizing in nature and exhibit some common properties such as the power law degree distribution. Recently, two models (i.e., small world and scale-free network models) have been proposed and successfully used to describe the nature of such networks. In this article we investigate whether these concepts can also be applied to cellular wireless networks, which typically do not exhibit self-organizing or scalability properties due to the limited range of the wireless nodes. Our ultimate goal is to design robust, reliable, scalable, and efficiently utilized wireless networks via self-organizing mechanisms.