IPv4向IPv6过渡的技术与过程

随着Internet技术的迅速发展,IPv4协议逐渐不能满足社会的需要。总结IPv4协议的不足之处,并在此基础上提出IPv6协议,论述当前IPv4向IPv6过渡的几种技术。同时综述IPv4向IPv6过渡技术选择原则。     

互联网协议中IPv6过渡机制的探讨

IPv6是用于取代现行互联网协议IPv4的新一代互联网协议,这是一种没有上限的网络基础资源,可以彻底解决IPv4地址不足的问题。但由于IPv4与IPv6之间存在着很大的差异,同时存在众多基于IPv4协议的网络及应用,因此,要用新的IPv6代替旧的IPv4必然存在一个过渡时期。重点分析实现从IPv4网络迁移到IPv6网络的过渡机制。     

IPv4协议和IPv6协议的比较

随着互联网络的发展,IPv4的不足之处逐渐显现出来,如地址空间危机、安全性差和服务质量不高等,IPv6协议是为解决IPv4协议的不足而提出来的。简单介绍IPv6协议,然后从IPv4和IPv6的表示方法、报头首部、地址类型、安全策略以及地址解析等方面进行比较,并说明IPv6的优势。     

IPv4向IPv6过渡技术分析

随着Internet的飞速发展,IPv4地址已经几乎耗尽,IPv6必将取代IPv4,本文重点介绍了IPv4过渡到IPv6的三种关键技术,分别是双协议栈技术、隧道技术、协议转换技术,并分析了如何根据具体情况选择适合的技术。     

校园网从IPv4到IPv6的过渡策略研究

IPv6已被认为是下一代互联网络协议核心标准之一。本文首先从IPv4的缺点和IPv6的优点出发分析了IPv6网络取代IPv4网络的必然性;然后研究了IPv6及IPv4向IPv6过渡的技术;最后提出了基于现有技术的校园网从IPv4到IPv6的过渡策略和相应的升级方案。     

IPv4向IPv6的过渡分析与应用

随着计算机技术、网络技术及软件技术的发展,已经使用多年的TCP/IP协议族中的IP协议日渐显露出许多问题,尤其是IPv4的地址资源即将被耗尽。分析IPv6的主要技术性能,及从IPv4过渡到IPv6的几种方案。     

IPv6的寻址浅谈

随着互联网的不断发展,有限的IPv4协议地址严重地制约互联网的应用和发展,于是IPv6协议应运而生,介绍IPv6的寻址体系结构,包括IPv6寻址模型、IPv6地址的文字表示、IPv6单播地址、任意点播地址和多播地址的定义。     

下一代网络:从IPv4到IPv6的过渡

目前的IP网络基本上采用IPv4协议,然而当前的网络越来越不能满足网络技术与应用发展的需求,因此作为下一代网络业务承载网核心的IPv6的发展就显得尤其的至关重要。尤其是IPv6将来在实现数字家庭中的应用尤为广泛,安全特性和服务质量的提高增大IPv6的竞争性,同时IPv6的发展推动移动IPv6、网络视频监控和IPTV的诞生和发展。     

浅析如何解决IPv4／IPv6过渡的兼容问题

介绍IPv4向IPv6过渡的三种重要机制,并针对三种机制提出相应的解决方案.实现IPv6"小岛"与IPv4"海洋"之间的通信以及IPv6"小岛"之间的通信。     

现代网络中IPv6技术的应用

IPv6协议是因特网新一代通信协议,在IPv6取代IPv4网络的进程中,始终存在着两个网域内的系统之间的相互连通的问题,而IPv4与IPv6网络互连技术的实现是关系到IPv4NIPv6是否能够平稳过渡,以及Internet是否能够保持长期的可持续发展的关键问题,因此对过渡技术的研究与实现有着重要的现实意义。     

基于前缀区间和前缀层次(PRPL)的IPv6路由查找算法

通过对前缀区间（PR）和前缀层次（PL）的研究,并结合IPv6全球单播地址和IPv6骨干网路由表的特征,提出了一种基于前缀区间和前缀层次（PRPL）的高性能的IPv6路由查找算法。通过使用合成的不同数据量的IPv6路由表对该算法进行了测试,测试结果表明该算法的可扩展性非常出色,它能够支持数据量达到。200k的大路由表。与同样环境下的经典算法的测试结果进行了比较,比较结果也表明该算法在平均查找速度和内存消耗方面都有一定的优势。出色的性能和对大路由表的支持,使得该算法能够应用到骨干网IPv6路由器中。     

下一代互联网IPv6的标准化实践(英文)

Premier Wen Jiabao held an executive meeting of the State Council deploying measures for speeding up the NGI development on December 23, 2011, which symbolizes that China has put the development of NGI to a strategic position. In the development of NGI, standards and norms has always played an important role in pushing the development of the industry. This essay discusses the latest progress of NGI and introduces the research results CHINA TELECOM has made in international standard IPv6 IETF, domestic standard CCSA and relevant enterprise standards.     

A Decision-Based Hybrid Proxy Mobile IPv6 Scheme for Better ResourcesUtilization

Seamless mobility is always one of the major requirements of modern-day communication. In a heterogeneous and massive IoT environment, efficient network-based mobility protocol such as proxy mobile IPv6 (PMIPv6), is potentially a good candidate for efficient mobility as well as resource utilization efficiency. Several extensions are devised for performance in the research domain. However, a multi-criterion decision-based resource-efficient PMIPv6 extension is required to achieve efficiency when network resources are overloaded. In this research, a multi-criterion decision-based PMIPv6 scheme is devised that provides better performance when the Local Mobility Anchor (LMA) or Mobile Access Gateway (MAG) is overloaded. The objective is achieved by monitoring the load status of MAG or LMA and based on their status, the proposed scheme adapts itself to provide seamless mobility in addition to optimal efficiency. The proposed scheme is compared with the existing LMA and MAG-based mobility management protocol extensions. Based on the analysis of the comparison, the obtained results prove that providing a decision-based PMIPv6 scheme is better for service continuity as well as optimal performance in the context of required buffering, handover efficiency, and necessary signaling cost.     

Cross-layer binding update for TCP performance enhancement over Mobile IPv6 networks

Mobility support in Internet Protocol version 6 (IPv6) is a de facto standard for allowing nodes to remain connected while moving around in the IPv6 networks. To provide better handoff latency and performance, numerous optimisation techniques were developed. Some of them are single-layer optimisation such as the hierarchical mobile IPv6 architecture, which aims at reducing the registration time in network layer. Others are cross-layer optimisation such as the fast handover mechanism, which tries to reduce the address resolution time in network layer based on the data-link layer detection. Most of these techniques are focused on data-link and network layer optimisation. The authors propose a cross-layer mechanism, which uses the standard binding update packet in mobile IPv6 handoff to enhance the overall transmission control protocol performance in transmission. The theoretical analysis and simulations show promising performance enhancements.     

基于IPv6的PIM-SMv2协议的设计与实现

在新一代互联网中,支持组播已成为对路由器的基本要求。PIM-SM是一个不依赖于某一特定单播路由协议的组播路由协议,为组播数据转发提供路由信息。本文介绍了高性能：IPv6路由器协议栈软件中基于原始套接字(Raw Socket)通信机制的PIM—SMv2协议的设计与实现,并搭建实验环境对实现的系统进行了测试。实验结果表明,该系统已具备IPv6组播功能。     

An Alias Resolution Method Based on Delay Sequence Analysis

Alias resolution, mapping IP addresses to routers, is a critical step in obtaining a network topology. The latest work on alias resolution is based on special fields in the packet, such as IP ID, port number, etc. However, for security reasons, most network devices block packets for setting options, and some related fields exist only in IPv4, so these methods cannot be used for alias resolution of IPv6. In order to solve the above problems, we propose an alias analysis method based on delay sequence analysis. In this article, we present a new model to describe the distribution of Internet delays and give a mathematical proof. After experimental measurements using the Macroscopic Internet Topology Data Kit (ITDK) and Ark IPv6 Topology Dataset, it was found that the statistical differences in most alias delay models were very small. The statistical differences in the non-alias delay models are spread over a wide range. Using the wavelet decomposition in delay sequence, it was found that the approximate components and the detail components of the delay sequence of aliases were the same after filtering out the noise, which provided a theoretical explanation for the experimental results. This technology is applicable to both IPv4 and IPv6.     

Enabling peer-to-peer communication for hosts in private address realms using IPv4 LSRR option and IPv4+4 addresses

Enabling peer-to-peer (P2P) communication for hosts behind network address translation (NAT) boxes is an important and difficult problem. Existing proposals, for example, UPnP, MIDCOM, TURN, STUN, STUNT, P2PNAT, NATBlaster among others, offer only partial, limited and non-deterministic solutions. A framework that offers a complete solution to the P2P communication problem is presented. The proposed framework is based on the use of IPv4+4 addresses and the standard IPv4 Loose Source Record Route (LSRR) option and requires no changes whatsoever to end-host protocol stacks and Internet routers. The only requirement is a simple upgrade of border routers with a new LSRR-based packet-forwarding algorithm for the P2P traffic. The implementation of a Linux-based border router that runs the proposed forwarding algorithm is detailed, and how P2P applications can benefit from this framework is described.     

分层移动IPv6中呼叫接入控制的动态优化

对分层移动IPv6中的无线资源管理问题进行了研究,提出了一种基于动态阈值的呼叫接入控制(DT-CAC)策略。DT-CAC通过建立小区呼叫接入的马尔可夫排队模型,根据网络负载状态的变化对切换呼叫和新呼叫的接入阈值进行动态调整,在减少切换呼叫掉线率的同时限制新呼叫阻塞率的增加,从而在切换呼叫掉线率和新呼叫阻塞率之间取得平衡。大量仿真结果表明,DT-CAC与现有协议相比,在减小新呼叫阻塞率和切换呼叫掉线率以及提高资源利用率等方面具有较好的性能。当呼叫流量较大时,DT-CAC的新呼叫阻塞率和切换呼叫掉线率可以减少约6%左右,资源利用率可以达85%以上。     

6H-SiC材料与器件辐照效应的研究进展

介绍了6H-SiC材料和器件辐照效应研究的目的和方法,并对国内外最近几年的研究情况进行了介绍、分析和总结.指出目前的研究主要集中于辐射效应方面,但在抗辐射加固技术方面研究不足,国内应根据现有条件注重辐射效应机理方面的研究.     

5G Smart Mobility Management Based Fuzzy Logic Controller Unit

In the paper, we propose a fuzzy logic controller system to be implemented for smart mobility management in the 5G wireless communication network. Mobility management is considered as a main issue for all-IP mobile networks future generation. As a network-based mobility management protocol, Internet Engineering Task Force developed the Proxy Mobile IPv6 (PMIPv6) in order to support the mobility of IP devices, and many other results were presented to reduce latency handover and the amount of PMIPv6 signaling, but it is not enough for the application needs in real-time. The present paper describes an approach based on the IEEE 802.21 Media Independent Handover (MIH) standard and PMIPv6, so we present a new vertical handover algorithm for anticipating handover process efficiently. Our object is to propose a smart mobility management that contribute in 5G wireless communication system network operating functions. Two proposed dynamic thresholds were successfully made to guaranty process triggering, and a new primitive MIH is proposed for signaling a needed handover to be done. Simulation results demonstrate a significant reduction of the handover delay, packet loss, handover blocking probability and signaling overhead. Simulation results and tests are accomplished.