【作者】 李新；

【导师】 高强；

【作者基本信息】 北京邮电大学 ， 计算机应用技术， 2010， 硕士

【摘要】 未来通信将是一个以IPv6为基础的全IP异构网络。各种业务的发展也使得人们对移动性的需求越来越高。因此,研究多模终端在异种网络间的切换问题,具有重大的现实意义。为了研究采用移动IPv6技术来实现融合的方法和在实际中应用的效果,本文首先搭建了分层移动IPv6实验床,并在分析实验床实现代码的基础上,对该实验床进行了改进与扩展,使其对双接口提供支持,从而为异构网络环境的切换研究提供了环境。基于该实验系统的基本分层移动IPv6切换性能测试中时延在2s以上,丢包率也在10%以上。这些性能没法满足实时业务的需求,为了改进实验系统的切换的性能,使其满足实时业务的需求,引入并在实验系统中实现了IP层软切换算法。并经过多次测试证明实验床中该算法的切换时延和丢包率都接近于0,确实大大的提高了切换的性能。软切换虽然改进了切换性能,但是是以双倍链路通信为代价的,所以在对双模软切换链路代价分析的基础上,提出了一种能根据链路的性能对切换策略合理权衡的自适应切换机制。并通过研究多目标网络选择判决方法解决了多目标网络下的自适应切换问题。另外,NETCONF协议作为未来网管协议的新方向,本文在研究NETCONF协议的基础上,开发和实现了NETCONF客户端软件。该软件的传输层采用SSH方案,测试验证了该软件能够实现get-config, edit-config, delete-config, lock, unlock等基本原语的操作,从而到对设备进行配置管理的目的。更多还原

【Abstract】 In the future, communications will be built on the all-IP heterogeneous network based IPv6. The demand for mobility increased with the development of business. Therefore, the research of handoff for heterogeneous networks is of great significances.In order to research the integration methods using mobile IPv6 technology and the effect of this in the application, HMIPv6 Test-bed is built. And after analyzing the software code of the test-bed, we improve it to support for dual interfaces. This provides a foundation environment for the research of handoff in heterogeneous networks.Based on the handoff experiment in the test-bed of basic HMIPv6, we find that the delay of the handoff more than 2 seconds and packet loss rate of that more than 10%. The performance can not meet the timely needs of business. In order to improve the performance of the handoff, The IP-layer soft-handoff scheme is applied in the test-bed. And after several tests, it proves that the delay and packet loss rates are close to zero. The soft-handoff scheme greatly improved the handoff performance.Although the soft-handoff scheme can improve the handoff performance, it needs two communication links to finish the handoff. Therefore, after analyzing the cost of the dual-link caused by soft-handoff, we propose an adaptive handoff mechanism to weigh the cost and the performance. The adaptive handoff mechanism will make a reasonable handoff strategy according to the condition of link.And by studying the method of multi-objective network selection, the adaptive handoff mechanism will be applied to multi-objective network.In addition, the NETCONF protocol is the application trend for network management protocol. After investigating the NETCONF protocol, we impletment the NETCONF client software. In this software, the transport layer of NETCONF used SSH. The experiment proves that the software can achieve the basic primitives of the operation sush as get-config, edit-config, delete-config, lock, unlock. So it has the ablity that configure and manage the device.更多还原