基于Mtrace的Ipv6组播监听的实现

针对日益增多的高带宽需求的多媒体应用，下一代互联网协议——IPv6提供了增强的组播技术。在IPv4向IPv6推进的过程中，一些IPv6环境下组播相关的问题亟待解决，其中之一就是提供用于组播管理的工具。介绍了IPv6组播相关技术，并基于Mtrace在开源的IPv6协议栈——KAME上实现了一个IPv6组播路由查找工具。     

IPv4-IPv6组播过渡技术

要使IPv4主机与IPv6主机进行组播通信，必须做协议转换工作。采用多播转换网关（MTG）技术方案能较好地实现IPv4网和IPv6网之间的组播互通。方法是将MTG部署在lPv4和IPv6网络的边界，将IPv4网络和IPv6网络视为地位对等的两个异构网络。IPv6主机可以加入组播源位于IPv4网络的组播组，IPv4主机也可以加入组播源位于IPv6网络的组播组。在IPv4中，MTG作为IPv6的代理，参与IPv4的组播；同样，MTG在IPv6中则作为IPv4的代理。在MTG系统内部，两个代理之间进行协议转换。     

基于IPV6的组播路由协议PIM-SM的研究及实现

文章首先分析了研究IPv6组播技术的重要意义.然后详细分析了组播路由协议PIM-SM,并且在实验室生成IPv6环境下,对PIM-SM协议中的BSR选举、RP竞争、HelIo消息发布和数据流树切换等进行了测试,测试结果表明该协议工作正常,以其为基础实现的组播系统是正确的,符合RFC相关文档说明.     

IPv6组播技术综述

综述了IPv6组播的新特性及相关协议，指出目前组播技术的研究热点，介绍了当前国内外IPv6组播标准研究、协议实现及试验网的情况。     

基于IPv6的QoS控制组播路由机制

设计并实现了一种基于IPv6的QoS(quality of service)控制组播路由机制.基于启发式单播路由协议,修改了PIM-SSM协议与MLD协议,实现了IPv6下启发式源特定组播.为提供QoS控制,扩展了RSVP协议,设计了分层组播流量控制机制,基于博弈分析确定为用户预留的带宽量,优化网络提供方与用户方效用.开发了该机制的原型系统并进行了大量试验,结果表明该机制具有良好的性能,能够提供IPv6下的QoS控制组播路由.     

一种新的IPv6任播地址解析协议及应用

任播技术是一种新的网络应用。任播通信是支特导向服务地址的，但是目前IPv6中它的很多定义是模糊的，并且在控制路由方面没有选成一致的协议标准，因此节点间任播通信仍然无法实现。首先说明了基于IPv6的任播通信及目前在该领域中存在许多可能的应用，并指出一些问题和与之对应的解决办法，随后介绍了一种使用特殊任播地址来建立TCP连接的任播地址解析协议(AARP)，使得任播地址在适应已经存在的应用和高层协议时，不需要修改或者扩展的情况下更加有效。     

IPv6组播技术及其在IPTV中的应用

本文在研究IPv6组播技术的基础上,深入分析IPTV直播业务模型,从基于MLD的频道切换和可控组播技术分析IPv6组播技术在IPTV中的应用。     

IPv6组播技术的研究和实现

文章介绍IP组播的基本原理,在分析IPv6组播协议工作原理的基础上,提出基于IPv6的PIM-SM协议的实现方案。     

局域网中的IPv6

文章分析了IPv6实施以后,局域网中几个重要协议的变化,包括手工配置IPv6地址和自动配置IPv6地址的协议,组播应用的增多和组播协议的改进,邻居发现协议取代ARP解析地址的过程。Internet可以看成是用路由器连接起来的多个局域网的网络,终端用户使用IPv6,最先的体验也可能是在局域网中。     

IPv6协议一致性测试的实现

在863课题“IPv6协议测试技术”的支持下，以提供IPv6测试能力为着眼点，讨论了与IPv6测试相关的测试集描述语言、测试平台设计、测试方法、测试集生成等几个方面的技术，介绍了功能完善的IPv6一致性测试平台及完整的IPv6协议测试集，并对几种常见的IPv6协议实现进行了实际测试。     

ON MULTICAST TREE CONSTRUCTION IN IPV4-IPV6 HYBRID NETWORK

With the IPv4 addresses exhausting and IPv6 emerging,the Peer-to-Peer (P2P) overlay is becoming increasingly heterogeneous and complex: pure IPv4,dual stack and pure IPv6 hosts coexist,and the connectivity limitation between IPv4 and IPv6 hosts requires the overlay protocols to be fit for this hybrid situation. This paper sets out to answer the question of how to construct multicast tree on top of IPv4-IPv6 hybrid network. Our solution is a New Greedy Algorithm (NGA) which eliminates the problem of joining failure in the hybrid network and keeps the efficiency of greedy algorithm in tree construction. Simulation results show that our algorithm has excellent performance,which is very close to the optimal in many cases.     

Arranging multicast forwarding table in class sequence in ternary-cam for line-speed lookup

PIM-SM (Protocol Independent Multicast-Sparse Mode) is a main multicast routing protocol in the IPv6 (Internet Protocol version 6). It can use either a shared tree or a shortest path tree to deliver data packets, consequently the multicast IP lookup engine requires, in some cases, two searches to get a correct lookup result according to its multicast forwarding rule, and it may result in a new requirement of doubling the lookup speed of the lookup engine. The ordinary method to satisfy this requirement in TCAM (Ternary Content Addressable Memory) based lookup engines is to exploit parallelism among multiple TCAMs. However, traditional parallel methods always induce more resources and higher design difficulty. We propose in this paper a novel approach to solve this problem. By arranging multicast forwarding table in class sequence in TCAM and making full use of the intrinsic characteristic of the TCAM, our approach can get the right lookup result with just one search and a single TCAM, while keeping the hardware of lookup engine unchanged. Experimental results have shown that the approach make it possible to satisfy forwarding IPv6 multicast packets at the full link rate of 20 Gb/s with just one TCAM with the current TCAM chip.     

IPv6网络中组播路由--PIM技术研究

随着网络宽带用户和下一代互联网的发展,多媒体业务相关服务如网络电视(IPTV)需求的日益增长刺激了IP组播技术的普及和发展,使其成为新一代网络中不可缺少的关键技术.与单播应用相比,采用IP组播技术分发信息常常能从本质上减少整个网络对带宽的需求.文章从IPv6网络的各种组播技术入手,详细介绍了当前在实际网络中获得广泛应用的基于协议无关组播(PIM)的组播路由技术 ,重点介绍了域内组播路由中使用最广泛的PIM稀疏模式(PIM-SM).对整个PIM-SM组播路由协议在IPv6网络中的运行过程进行了论述,最后介绍了其在未来IPTV等网络应用中的前景.     

基于统计的高效决策树分组分类算法

基于决策树的分组分类算法因易于实现和高效性,在快速分组分类中广泛使用。决策树算法的基本目标是构造一棵存储高效且查找时间复杂度低的决策树。设计了一种基于规则集统计特性和评价指标的决策树算法——HyperEC 算法。HyperEC算法避免了在构建决策树过程中决策树高度过高和存储空间膨胀的问题。HyperEC算法对IP地址长度不敏感,同样适用于IPv6的多维分组分类。实验证明,HyperEC算法当规则数量较少时,与HyperCuts基本相同,但随着规则数量的增加,该算法在决策树高度、存储空间占用和查找性能方面都明显优于经典的决策树算法。     

Independent-Tree Ad hoc MulticAst Routing (ITAMAR)

Multicasting is an efficient means of one to many communication and is typically implemented by creating a multicasting tree. Because of the severe battery power and transmission bandwidth limitations in ad hoc networks, multicast routing can significantly improve the performance of this type of network. However, due to the frequent and hard-to-predict topological changes of ad hoc networks, maintenance of a multicasting tree to ensure its availability could be a difficult task. We borrow from the concept of Alternate Path routing, which has been studied for providing QOS routing, effective congestion control, security, and route failure protection, to propose a scheme in which a set of multicasting trees is continuously maintained. In our scheme, a tree is used until it fails, at which time it is replaced by an alternative tree in the set, so that the time between failure of a tree and resumption of multicast routing is minimal. In this paper, we introduce the basic scheme, termed ITAMAR, which is a framework for efficient multicasting in ad hoc networks. We present a number of heuristics that could be used in ITAMAR to compute a set of alternate trees. The heuristics are then compared in terms of transmission cost, improvement in the average time between multicast failures and the probability of usefulness. Simulations show significant gains over a wide range of network operational conditions. In particular, we show that using alternate trees has the potential of improving mean time between interruption by 100–600% in a 50 node network (for most multicast group sizes) with small increase in the tree cost and the route discovery overhead. We show that by renewing the backup tree set, probability of interruptions can be kept at a minimum at all times and that allowing some overlap among trees in the backup set increases the mean time between interruptions.     

On multicast tree construction in IPV4–IPV6 hybrid network

With the IPv4 addresses exhausting and IPv6 emerging, the Peer-to-Peer (P2P) overlay is becoming increasingly heterogeneous and complex: pure IPv4, dual stack and pure IPv6 hosts coexist, and the connectivity limitation between IPv4 and IPv6 hosts requires the overlay protocols to be fit for this hybrid situation. This paper sets out to answer the question of how to construct multicast tree on top of IPv4-IPv6 hybrid network. Our solution is a New Greedy Algorithm (NGA) which eliminates the problem of joining failure in the hybrid network and keeps the efficiency of greedy algorithm in tree construction. Simulation results show that our algorithm has excellent performance, which is very close to the optimal in many cases.     

Realization of IPv6 Multicast Interworking between MANET and Fixed Networks

1　Introduction[1～3]Themeaningof“adhoc”issolvingaproblemasitoccurswithoutpreparationbeforehand .There fore ,aMANETisanetworkthatconsistsofwire lessMobileNodes (MNs) ,whichisestablishedasitisneededwithoutany pre existinginfrastructure.AsshowninFig .1 ,whensomeMNsgettoclose,theycancommunicatewitheachotherviapotentialFig .1　MANETmulti hopfeaturemultiplehopsconnections,thatis,ifthenodeSwantstocommunicatewithnodeD ,itsmessageshavetoberelayedbynodeAandnodeB ,whichconstructsathree hopcon…     

Multicasting on translucent multicast capable WDM mesh networks

As multicast applications becoming widely popular, supporting multicast in wavelength division multiplexing (WDM) networks is an important issue. Currently, there are two schemes to support multicast in WDM networks. One scheme is opaque multicasting which replicate bit stream in electronic domain. And the other is transparent multicasting which replicate bit stream all optically by a light splitter. However, both of two schemes have drawbacks or difficulties. This paper investigates an alternate translucent multicasting scheme, in which a fraction of branch nodes replicate bit stream at electronic domain and the other branch nodes replicate bit stream all optically. Replicating bit stream at electronic domain will introduce electronic processing overhead and extra delay. To satisfy the delay requirement of multicast session, the maximum number of electronic hops of a multicast tree must be less than an upper bound. In this paper, a hop-constrained multicast routing heuristic algorithm called shortest path based hop-constrained multicast routing (SPHMR) is proposed. A series of simulations are conducted to evaluate the effectiveness of translucent multicasting scheme. Simulation results show that the translucent multicasting scheme achieve a good compromise between network performance and network cost as well as power losses caused by light splitting.