基于PMIPv6的域间切换管理方法及性能分析*

针对代理移动IPv6（PMIPv6）中域间切换时延较大的问题,提出了一种基于PMIPv6的域间切换管理方案。新方案通过在PMIPv6域间发送PBU绑定更新消息,使得切换目标PMIPv6域提前知道移动节点（MN）的家乡网络前缀,避免了移动节点参与移动性管理及重新配置转交地址,从而有效减小了切换时延。分析和仿真结果表明,与现有的全局移动性管理方案移动IPv6和快速移动IPv6相比较,新方案更加适应移动性管理中低时延、低复杂度、易于操作的要求。     

Performance analysis of Virtual Mobility Domain scheme vs. IPv6 mobility protocols

The population of mobile users seeking connectivity to the Internet has been growing over the years, spurred by the capabilities of handsets and the increasing rich Internet content and services. Mobility management to enable efficient Internet access for users on the move is thus gaining significance. IETF has standardized several protocols such as Mobile IPv6, Hierarchical Mobile IPv6, and Proxy Mobile IPv6 to provide mobility management on the IP network. With future Internet design initiatives gaining momentum, it is important that these initiatives consider mobility management as an integral part of the design. In this article, we introduce the concept of Virtual Mobility Domain and describe the main features and key strengths of Virtual Mobility Domain that are designed to provide mobility management in a newly proposed tiered Internet architecture. Instead of IP addressing, the proposed Virtual Mobility Domain uses a tiered-addressing scheme to identify a mobile node with a single address regardless of its location. The tiered addressing provides a dynamic address length which brings less signaling overhead and scalable management. We also propose a collaborative network-based mobility management mechanism to provide low-latency handoffs and less processing-overhead on the mobile node compared to the IPv6-based protocols. The proposed mobility scheme unifies inter and intra-domain mobility management by introducing common anchor cloud concept which provides a distributed management and seamless mobility experience. We present comparative qualitative and quantitative performance analysis of Virtual Mobility Domain and aforementioned IPv6-based mobility protocols for Intra-AS roaming support. We examine handoff latency and signaling overhead performance of each protocol based on numerical results retrieved from analytical models and OPNET modeler based simulations. The results from a comparative performance study show the potential for more efficient mobility management under the proposed Internet architecture.     

Cost-effective approach inter-LMA domain management and distributed mobility control scheme in proxy mobile IPv6 networks

The Proxy Mobile IPv6 (PMIPv6) is designed to provide network-based mobility management support to a mobile node (MN) without any involvement of the MN in mobility related signaling; hence, the proxy mobility entity performs all related signaling on behalf of the MN. The new principal functional entities of PMIPv6 are the local mobility anchor (LMA) and the mobile access gateway (MAG). In PMIPv6, all the data traffic sent from the MN gets routed to the LMA through a tunnel between the LMA and the MAG, but it still has a single point of failure (SPOF) and a bottleneck state of traffic. To solve these problems, various approaches directed towards PMIPv6 performance improvements, such as route optimization, have been proposed. However, these approaches add additional signaling to support the MN׳s mobility, which incurs extra network overhead and still provides difficulty when applied to multiple-LMA networks. In this paper, we propose an improved route optimization in PMIPv6-based multiple-LMA networks. All LMAs were connected to the proxy internetworking gateway (PIG), which performs inter-domain distributed mobility control. Each MAG keeps the information of all LMAs in the PMIPv6 domain, so it is possible to perform fast route optimization. Therefore, this method supported route optimization without any additional signaling because the LMA receives the state information of route optimization from the PIG.     

PMIPv6域中基于扩展信令的网络移动性优化方法

针对PMIPv6域中支持网络移动性存在的总开销过大问题,提出一种基于扩展信令的网络移动性优化方法。利用扩展的信令消息,整合位置更新和转发数据过程,均衡降低了系统的位置开销和隧道开销。性能分析表明,相比传统机制,本方案有效降低了系统总开销。     

代理移动IPv6认证授权实现

代理移动IPv6协议是基于网络移动管理协议,是未来网络重要的移动性协议体系。代理移动IPv6认证授权实现给出了代理移动IPv6认证授权的设计方案,实现对接入网络中的移动节点进行接入认证和服务授权,并对该系统进行功能验证和性能分析实验,结果验证了设计有效可行。     

基于快速切换的代理移动IPv6路由优化方案

针对代理移动IPv6移动节点(MN)切换后重建优化路径时延较长问题,提出一种基于快速切换的路由优化方案。新方案通过在MN快速切换过程中由旧移动接入网关提前发起路由优化,实现了优化路径的快速重建。性能分析表明,新域内路由优化方案比局部移动锚点发起的路由优化方案减少了21.7%的路由优化平均费用和45.4%的路由优化状态建立时延;新域间路由优化方案比现有域间切换及路由优化方案减少了72.2%的路由优化状态建立时延。     

代理移动IPv6多接口接入分析与测试

未来移动节点必须支持多个网络接口的应用。代理移动IPv6（PMIPv6）协议可以为移动节点提供基于网络的移动性管理,不需要移动节点参与移动性管理。分析了多接口技术在PMIPv6下的应用,详述了基于虚拟接口实现多接口接入PMIPv6的方法。在实验室集成开发环境下进行了实验测试,测试表明基于虚拟接口的PMIPv6多接口接入基本实现了多家乡和异构切换功能。     

Security analysis of fast inter-LMA domain handover scheme in proxy mobile IPv6 networks

The PMIPv6 is vulnerable to various security threats such as the DoS or redirect attacks. In this paper, we analyzed the Kang–Park & ESS-FH scheme, and proposed an Enhanced Security scheme for FPMIPv6 (ESS-FP). Based on the CGA method and the public key Cryptography, ESS-FP provides a strong key exchange and key independence in addition to improving the weaknesses of FPMIPv6. The proposed scheme was formally verified based on Ban-logic, and its handover latency was analyzed and compared with that of the Kang–Park scheme & ESS-FH. In addition, we proposed an inter-domain fast handover scheme for PMIPv6 using the proxy-based FPMIPv6.     

基于无证书签密的代理移动IPv6认证方案*

针对现有的代理移动IPv6认证方案存在的系统开销大和不能抵御暴力攻击的问题,提出了一种基于无证书签密的代理移动IPv6认证方案。该方案结合了无证书签密和代理移动IPv6的实际环境,在实现对移动节点认证的同时有效地解决了无线环境中密钥管理问题。对方案的安全性进行形式化分析证明,该方案在随机预言机模型下是可证明安全的。同时,效率分析表明,该方案不仅减少了节点之间的交互,而且保持了较小的计算量。     

IPv6网络中DNS蠕虫的研究

基于IPv6网络环境分析了网络蠕虫的扫描策略,构建了一种新型网络蠕虫--DNSWorm-V6,该蠕虫应用两层不同的扫描策略,即在本地应用子网内扫描策略,在子网间应用DNS扫描策略.由此两层扫描策略,提出一种双层蠕虫传播模型TLM.仿真实验结果表明,DNSWorm-V6是一种可以在IPv6网络中大范围快速传播的蠕虫.可以预测IPv6网络中新型蠕虫可能带来的威胁.     

基于IPv6网络的移动管理系统研究

移动IP是一个解决在现有因特网中提供漫游功能的通讯协议,但这个架构下有着传统的三角路由问题,造成传送距离太过冗长而导致效能不彰的问题。虽然一些路由优化的方法通过更改网络中现有的主机或服务器可以解决这个问题。但在未来的IPv6因特网环境上,使用者不太可能记住128位地址,因此本文考虑在未来的IPv6环境中利用移动管理系统(MMS)与DNS系统相互结合来解决三角绕送的问题。     

移动IPv6环境下平滑切换对TCP性能的影响

Mobile IPv6引入了平滑切换(Smiooth Handoff)的概念,目的是尽量减少移动节点(MN)在切换中的丢包,做到无缝切换。介绍了Mobile IPv6中平滑切换的过程,对于移动节点在平滑切换时TCP的性能进行了仿真,分析仿真结果中存在的问题,为以后进一步的研究提供重要的参考。     

改进的快速层次移动IPv6方案

F-HMIPv6有效地结合了快速切换和层次移动管理模型,首先介绍了F-HMIPV6的工作原理,然后分析了其中存在的问题。提出了一种改进的方案,该方案能进一步减少分组丢失,同时减少隧道建立的时间。     

Performance Evaluation of Fast Handover in Mobile IPv6 Based on Link-Layer Information

Handover latency is the primary cause of packet loss resulting in performance degradation of standard Mobile IPv6. Mobile IPv6 with fast Handover enables a Mobile Node (MN) to quickly detect at the IP layer that it has moved to a new subnet by receiving link-related information from the link-layer; furthermore it gathers anticipative information about the new Access Point (AP) and the associated subnet prefix when the MN is still connected to the previous Corresponding Node (CN).This paper proposes an enhancement to Fast Mobile IPv6 handover (FMIPv6), based on link layer information, we also present performance evaluations in terms of the packet loss and handover latency using evaluation models.     

Buffering in proxy mobile IPv6: implementation and analysis

Proxy mobile IPv6 (PMIPv6) is a network-based mobility management protocol that improves performance in terms of handover latency, signaling cost, and packet loss compared to host-based mobility management protocols. However, still packet loss occurs during the handover of the mobile node (MN). Several attempts have been made to improve the reliability of PMIPv6 service by proposing schemes in which packets are buffered in network entities during the handover of the MN to prevent packet loss, and performance improvement has been demonstrated via simulations. So far, there have been no implementations of buffering functions in the literature. This paper addresses design of buffering function and its implementation to prevent packet loss, and demonstrates the results. We have implemented a PMIPv6 testbed based on open source resources. We discuss the functional and performance enhancements, comparing PMIPv6 with the buffering implemented and standard PMIPv6. We also propose an improved buffering function where the packet forwarding rate of the buffer is adjusted. The results through the testbed show that the buffering function in PMIPv6 effectively prevents packet loss during the handover of the MN. We have found out that we can manage the amount of packets in the buffer without further increment by adjusting the packet forwarding rate of the buffer as well.     

移动IPV6越区切换管理模型的研究

移动IPv6为IPv6节点提供了在Internet中使用固定的家乡地址在不同子网中进行漫游通信的能力,然而当节点在网络间越区切换的时候,容易引起通信质量的下降或中断。针对标准移动IPv6和HMIPv6（层次化移动IPv6管理模型）对节点切换管理的不足,提出了一种新的越区切换管理模型方案,通过非固定的移动锚节点（MAP,Mobility Anchor Point）管理域,以及动态的MAP切换时机的选择,来达到降低切换行为的发生频率、保持切换发生时通信的连续性、使MAP负载均衡等目的。     

基于SIP的无线网络移动性管理研究

为了使移动设备能在无线IP网络中无缝漫游,无线IP网络必须要能提供有效的移动性管理来支持终端的移动性。基于SIP提出了一种新的应用层移动性管理方案,和已有的移动性管理方案相比,它既支持实时业务的快速切换,减少了切换时的延迟和丢包,也支持非实时业务,而且实现和部署起来比较简单方便。     

基于SIP的无线网络移动性管理研究

为了使移动设备能在无线IP网络中无缝漫游，无线IP网络必须要能提供有效的移动性管理来支持终端的移动性。基于SIP提出了一种新的应用层移动性管理方案，和已有的移动性管理方案相比，它既支持实时业务的快速切换，减少了切换时的延迟和丢包．也支持非实时业务，而且实现和部署起来比较简单方便。     

分级移动IPv6中的移动锚点选择算法

分析了分级移动IPv6（HMIPv6）现有移动锚点（MAP）选择算法的不足,提出了一种支持负载分担的新算法。该算法利用MAP的优先级值来表征MAP自身的负载情况,引入了分担门限对特定MAP的负载情况进行考察,并依据考察结果动态调整MAP选择策略,实现方法简单易行。仿真结果表明,该算法在有效减少协议开销的同时,达到了较好的负载分担效果。     

基于虚拟移动的IPv6主动防御方案

现有通过地址跳变对IPv6节点进行防护的技术依赖时间同步或事件同步,利用IPv6的良好移动特性和多转交地址注册机制,提出一种基于虚拟移动的IPv6主动防御方案。通过为IPv6节点分配动态变化的转交地址,使其呈现出在网络内不断移动的特征,降低攻击者对其实施攻击概率的同时,能够保证通信的持续。理论分析和实验测试表明,方案具有良好的抗攻击能力且较小的系统开销。