基于Ghost的多播系统

本文介绍了利用用Ghost企业版的多播功能进行网络多播克隆的技巧和方法，如何进行多播克隆服务器的安装以及客户端引导盘的制作，计算机模板映像文件的生成等。     

基于PXE技术的网络多播克隆设计与实现

介绍PXE技术及工作环境,分析网络多播克隆的实现原理,实现了PXE和TFTP技术相结合的Ghost多播克隆过程.     

基于PXE和ghost多播技术的网络克隆

该文介绍了利用GHOST7.5进行网络多播克隆的方法与技巧,论述了如何通过利用Ghost7.5企业版的网络远程功能,将DHCP服务和TFTP文件传输与PXE网络启动功能相结合,实现了局域网内计算机系统在无软驱和光驱情况下的网络多播克隆.     

浅谈计算机实训室维护技术——基于PXE技术的多播克隆

当前在计算机职业实验实训教学中,计算机系统维护工作一直是项非常繁重、繁琐的日常工作。该文通过阐述利用PXE引导技术结合ghostSrv网络多播克隆软件实现网络多播克隆,这一方法的具体实现过程,描述了PXE技术在机房维护方面的一个具体应用。     

巧用GHOST多播功能实现网络克隆

对目前计算机网络机房维护技术中，采用的Ghost多播功能进行了详细的研究，并详细指出了进行网络克隆快速恢复计算机软件系统的具体实现步骤。     

基于网络的高校计算机机房管理

该文讲述基于网络的高校计算机机房管理,运用网络多播克隆、硬盘还原卡从理论以及实践技术方面阐述了对计算机机房管理的有效性。     

基于主动网络的可靠多播路由协议

主动网络是一种允许用户对网络中间节点进行编程的新型网络结构，该文在多播网络系统模型基础上，探讨了主动网络可靠多播协议的特点和多播路由问题，提出了一个基于主动网络的可靠多播路由协议模型，该协议较好地减少了网络中大量的路由重构和分组的重传，缩短了错误发现和恢复时间。最后，利用仿真实验作了相关计算，给出了RMRPA协议的性能分析及与不可靠多播协议的比较。研究结果表明RMRPA协议为多媒体多播传输提供了一种新的有效途径。     

一种新型的可重排多播网络

在并行分布式系统中，多播操作（包括一对多播送和多源点多播）是一种常见的操作，关于多播操作（尤其是多源点多播）的研究是一个有一定难度，但又具有重要应用价值的问题，也是目前升级互连网络研究领域中的一个热门课题，已有的关于多播的成果大多只针对现有的多级网络，并且一般只能实现单个多播。Yang在[3]中针对多源点多播的并发。提出了一种新的多播网络，硬件复杂度为O（Nlog^2N).本文提出了一种基于Omega网的多播网络（5－Omega网），通过重排各级开关的状态，可以并发的实现任意的多源点多播，所需开关元件总数为5／2NlongN,与Yang提出的多播网络相比，硬件代价小得多，同时，5－Omega网上的多播路由时间复杂度能达到O（NlogN)，在相关的成果中也算是最优的，并且由于Omega网的结构较为简单，这种网的硬件集成也非常容易，因此更具有实用价值，在这种网络的构造基础上，还提出了一种新的多播网络模型，为以后设计多播网络提供了一种参考方法。     

边界路由器多播机制及其在MPLS网络中的应用

介绍了MPLS网络以及在MPLS网络中提供多播业务的难点，讨论并分析了一种MPLS环境下的边界路由器多播机制。边界路由器多播机制能有效地支持MPLS网络环境下的IP多播问题。     

基于主动网络的安全多播

研究了IP多播安全问题，提出了一种基于主动网络的安全多播技术。它能够比较好地解决IP多播中的数据保密性、完整性、多播组成员的身份认证与管理等问题；同时通过基于主动网络的系统结构可以很好地保证多播技术策略的灵活性，使用户可以及时方便地升级多播技术，调整多播策略。因此本技术具有安全性和灵活性等特点。     

Ghost组播服务在应用中需注意的问题

Ghost是最著名的硬盘复制备份工具,其企业版能通过网络同时从一台电脑上克隆多台电脑硬盘。具体阐述了在NortonGhost企业版的组播服务实施各环节中所应注意的问题以及改进方法。这些环节包括客户机引导盘的制作、母机映像文件的生成以及网络组播克隆。     

Topology Design of Network-Coding-Based Multicast Networks

It is anticipated that a large amount of multicast traffic needs to be supported in future communication networks. The network coding technique proposed recently is promising for establishing multicast connections with a significantly lower bandwidth requirement than that of traditional Steiner-tree-based multicast connections. How to design multicast network topologies with the consideration of efficiently supporting multicast by the network coding technique becomes an important issue now. It is notable, however, that the conventional algorithms for network topology design are mainly unicast-oriented, and they cannot be adopted directly for the efficient topology design of network-coding-based multicast networks by simply treating each multicast as multiple unicasts. In this paper, we consider for the first time the novel topology design problem of network-coding-based multicast networks. Based on the characteristics of multicast and network coding, we first formulate this problem as a mixed-integer nonlinear programming problem, which is NP-hard, and then propose two heuristic algorithms for it. The effectiveness of our heuristics is verified through simulation and comparison with the exhaustive search method. We demonstrate in this paper that, in the topology design of multicast networks, adopting the network coding technique to support multicast transmissions can significantly reduce the overall topology cost as compared to conventional unicast-oriented design and the Steiner-tree-based design.     

基于最大干扰网络编码的应用层多播算法

构建于终端系统的应用层多播具有网络层多播不可比拟的优势,为了提高应用层多播的效率和性能,提出一种基于最大干扰网络编码的应用层多播算法。该算法在采用网络编码的基础上,在多播路径选择上通过考虑源到多个目的节点路径间的最大干扰,来提高编码的利用效率,有效节省带宽。仿真表明,相比较一般应用层多播算法和基于网络编码的多播算法,本算法在提高网络吞吐量和资源利用率方面都有更好的表现。     

负载均衡的聚合组播技术研究

聚合组播技术是近年来针对组播状态可扩展性问题提出的热点方案,但现有的聚合组播算法和协议缺乏网络流量的负载均衡机制,使网络整体利用效率下降,并容易因聚合产生拥塞。为此,提出一种基于负载均衡的聚合组播协议AMPLB,仿真结果表明其在保证聚合性能的同时使网络流量分布更加均衡,降低出现拥塞的风险,可较好地改善大规模组播网络的性能。     

一种改进负载均衡的网络编码多播路由算法

已有研究证明,在多播网络中使用网络编码可以显著提高多播通信的性能。总结了网络编码多播理论的研究进展,同时对网络编码多播路由问题进行了研究与分析。考虑到影响链路负载和资源消耗的因素,提出了一种改进链路负载均衡的网络编码多播路由算法,优化了路径间链路的共享。通过使用常见的Waxman网络拓扑模型,产生随机网络拓扑。在这些拓扑中,分别针对传统IP多播路由、低速率网络下的网络编码多播路由以及提出的路由算法进行性能仿真。仿真结果表明,与其他两种路由算法相比,该算法在可达吞吐量、资源消耗和负载均衡等性能上均有很好的表现。     

Dynamic retransmission control for reliable mobile multicast

Most existing multicast protocols adopt a static retransmission scheme(unicast or multicast) to retransmit lost packets.In the mobile multicast environment,static multicast retransmission mode may lead to congestion in the receivers‘ wireless interfaces,while static unicast mode may result in great network load.Both static unicast and multicast retransmission modes will cause a performance loss.This paper logically divides the mobile multicast network into fixed and mobile parts,and focuses on the mobile part.Then this paper analyzes the retransmission costs when multicast or unicast mode is chosen.Two main parameters are used to compare their efficiencies:the average air-interface utilization of each receiver and the average network load.Based on the results of analysis,two new algorithms,called NLPA(Network Load Priority Algorithm)and AUPA(Air-interface Utilization Priority Algorithm)are presented.Finally,simulation results conclude that,with proper parameters,both NLPA and AUPA can dynamically alternate between unicast and multicast retransmission modes acording to the conditions of network and receiver,and avoid congestion in receivers‘ wireless interfaces as well as great network load,with a better use of network and terminal resources.     

Nonblocking k-fold multicast networks

Multicast communication involves transmitting information from a single source to multiple destinations and is a requirement in high-performance networks. Current trends in networking applications indicate an increasing demand in future networks for multicast capability. Many multicast applications require not only multicast capability, but also predictable communication performance such as guaranteed multicast latency and bandwidth. In this paper, we present a design for a nonblocking k-fold multicast network, in which any destination node can be involved in up to k simultaneous multicast connections in a nonblocking manner. We also develop an efficient routing algorithm for the network. As can be seen, a k-fold multicast network has significantly lower network cost than that of k copies of ordinary 1-fold multicast networks and is a cost effective choice for supporting arbitrary multicast communication.     

MPLS骨干网中环形管理组播树策略

在分析MMT, AMFM和ATMM等组播方案的基础上,针对其单一管理节点容易成为骨干网上组播的瓶颈,影响MPLS骨干网上组播树的健壮性问题,提出一种环形管理组播树的策略,通过对该策略的仿真分析,表明该策略能有效地解决单个管理节点超载和组播聚合树的信息丢失等问题,提高骨干网络中组播聚合树的效率和健壮性。     

On fair and optimal multi-source IP-multicast

We investigate the problem of maximizing multicast throughput under a fairness constraint. Multiple server nodes wish to communicate to their intended set of client nodes over a shared network infrastructure. Our goal is to devise distributed algorithms to construct multicast sessions, one for each server node, such that (a) the network infrastructure is optimally utilized and (b) the network resources are fairly distributed between multicast sessions, i.e., no individual session claims more than a prescribed share of the network bandwidth resources. We are particularly interested in multi-tree multicast strategies in which every multicast session may contain many multicast trees. We show how the use of multiple trees increases network throughput and the load distribution in the network. We propose a class of round-robin algorithms that are based on successive selection of multicast trees for each multicast session, in a loosely cooperative, yet distributed fashion. Our best algorithm, the Cooperative Shortest Path Tree Packing (CSPTP) algorithm, performs well in a variety of scenarios, ranging from very sparse to dense applications. Through extensive simulations on random networks, we compare the performance of our algorithms with those commonly used in IP-multicast as well as theoretical upper bounds derived from network coding formulations. We show that the CSPTP can improve the throughput, and often achieves about 90% of the theoretical upper bound.     

基于邻近原则的应用层组播实验研究*

提出了一个基于邻近原则的应用层组播系统,其覆盖网络由参与节点求得自身网络坐标之后,根据网络坐标基于邻近原则聚类形成。通过基于网络测量数据的仿真和PlanetLab真实网络环境中的实际测试,证明了基于该覆盖网络结构的应用层组播系统在性能指标上优于当前普遍应用的基于其他结构的覆盖网络的系统。在构建覆盖网络过程中考虑节点在网络中的位置分布等因素将能够提高基于该覆盖网络的应用层组播性能。