基于多层小区结构的移动IP移动性管理

1.引言为了支持全球的IP网络互通和设备的漫游,IETF提出了IP移动性支持协议——移动IP。其中规定:只要MN移动到另外一个IP子网,它就会获得另外的转交地址,从而启动注册过程,该过程要求MN必须通过FA向HA进行注册,MN的任何移动都必须报告给HA,由HA来维护MN的移动绑定。这种简单的移动性支持方案可以与现有网络兼容,并且只需要在移动代理(包括HA、FA)和MN上根据终端的移动性要求进行改进即可实现移动IP功能。当应用于“宏移动”(macro mobility)时,这是必要的和充分的,而当应用于“微移动”(micro mobility)和“快速移动”(high mobility)的环境时,则存在许多不足,突出表现在以下三点:1.在网络中将引发大量的注册报文的传输从而严重影响网络性能;2.造成较大的     

MG-HMIP协议模型的实现及应用

由于无线局域网(WLAN)IEEE802.11协议不能解决移动节点的三层漫游问题,介绍了WLAN与移动IP结合的解决方案。由于上述方案存在切换延时长、不支持微移动性等缺陷,研究了分层移动IP技术,并对分层移动IP进行了改进,提出了一个多GFA分层移动IP(MG-HMIP)模型,并详细介绍了MG-HMIP模型的注册机制和MN选择GFA的机制。最后,给出了MG-HMIP与WLAN结合的模型。这个改进的方案不仅解决了WLAN与传统的MobileIP结合所存在的切换延时长、频繁切换等问题,而且增强了分层移动IP的网络健壮性。     

移动IP的移动性管理研究

1 引言为了支持全球的IP网络互通和设备的漫游,IETF提出了IP移动性支持的规范——移动IP。该规范在移动IP网络结构中定义了三种功能实体(如图1):移动节点(MH)、归属代理(HA)和外地代理(FA)。每一个MH在归属网络获得一个永久的IP地址(home address),称为归属地址,当MH     

MG—HMIP协议模型的实现及应用

由于无线局域网（WLAN）IEEE802．11协议不能解决移动节点的三层漫游问题，介绍了WLAN与移动IP结合的解决方案。由于上述方案存在切换延时长、不支持微移动性等缺陷，研究了分层移动IP技术，并对分层移动IP进行了改进，提出了一个多GFA分层移动IP（MG—HMIP）模型，并详细介绍了MG—HMIP模型的注册机制和MN选择GFA的机制。最后，给出了MG—HMIP与WLAN结合的模型。这个改进的方案不仅解决了WLAN与传统的Mobile IP结合所存在的切换延时长、频繁切换等问题，而且增强了分层移动IP的网络健壮性。     

移动IP中的路由优化的改进方案

移动IP是一种对IP移动性的支持的协议，能够使移动主机（MH），借由家乡代理（HA）和外地代理（FA），直接向通信主机（CH）发送数据包。然而，所发送的数据包却不得不经过三个不同的网络：通信主机所在的子网，家乡代理所在的子网和移动主机当前所在的子网。这样，就使得发往移动主机的数据包要经过比预期长得多的路径。这些多余的路径在移动IP中被称为“三角路由”。这个问题可以用路由优化来解决，它要求所有通信主机保证一个绑定缓存，通信主机将从家乡代理中得到的移动主机的转交地址（CoA）储存在绑定缓存中，然后直接与移动主机进行对话。     

移动IP中的隧道技术

隧道技术解决了移动节点的移动性问题，对移动IP中使用的3种隧道技术做了简要的介绍。反向隧道的建立使得位于外地网络上的移动节点可以在设置了入口过滤路由器的外地网络上建立通信连接。通过在移动IP中应用IPSec协议，可以为移动IP提供有效的安全服务，使移动IP用户可以访问受防火墙保护的VPN，而不破坏原有的安全结构。     

嵌套NEMO中的路由优化方案研究

针对嵌套NEMO中存在的乒乓路由和数据包多层封装问题进行深入分析,提出一种嵌套NEMO的优化方案,改变NEMO中传统的MR嵌套转发报文的做法,使得MR的HA能够将发送到MR的数据直接重定向到整个嵌套NEMO所连接的外地网络,减少了嵌套的次数,并使得小范围的切换更新报文能控制在NEMO内部,减少了切换时延。分析表明,与NEMO基本支持协议相比,方案有效地解决了NEMO路由优化问题,提高了数据包的传输效率。     

基于多HA部署的MIPv6网络服务可用性提升方法

移动IPv6是实现下一代互联网移动特性的核心技术,依赖于部署在家乡链路的家乡代理(HA)实现节点移动过程中的可寻址性.家乡链路的单一HA部署,将成为系统的单点故障隐患及性能瓶颈,难以保证系统服务可用性.为提升移动IPv6网络的系统服务可用性和系统性能,需要在家乡链路部署多HA,解决其单点故障问题,并有效均衡多家乡代理间的负载.文中研究移动IPv6网络多家乡代理部署方法,引入检测备份环对多HA间进行有效组织,基于此实现HA容错和负载均衡.多家乡代理采用单一HA映像以实现容错及负载均衡处理对移动节点的透明性,减小处理延迟和开销.     

网络移动支持研究

未来移动互联网将由移动节点和移动网络组成。移动IP技术提供节点移动支持。移动网络技术提供网络移动支持。本文介绍了移动网络的应用需求、研究计划;然后对网络移动支持的基本要求和方法进行总结和阐述,并针对双向隧道法的IP隧道传输性能问题提出基于MPLS隧道的优化法;最后对网络移动支持的扩展要求进行讨论。     

改进型基于MPLS的HMIPv6的快速切换

针对现有的多协议标签交换(MPLS)和层次移动IPv6(HMIPv6)融合的方案仍然存在时延大、丢包率高等问题,提出了一种改进的基于MPLS的HMIPv6方案。本方案通过将多播技术应用于移动锚点(MAP),并且在切换完成之前提前完成新链路上标签交换路径(LSP)的建设,实现了移动节点(MN)移交切换时延的最小化,使得在切换过程中大大降低服务中断现象,最大限度地保证新链路建立完成之前数据包不被丢失。最后通过NS-2仿真与比较,结果表明本方案跟现有方案相比能够大大减少移动过程中的丢包率和传输时延,提高移动IP     

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.     

Effects of route optimization on out-of-order packet delivery in Mobile IP networks

Packet sequence disruption caused by route optimization may result in degradation of mobile TCP/IP performance. In this paper, we propose an analytic model to investigate the impact of route optimization on out-of-order packet delivery in Mobile IP networks. When a mobile node (MN) moves to a new location, the packets sent from the corresponding node (CN) to the MN are routed indirectly through the home agent (HA). After route optimization, the subsequent packets will be sent from the CN to the MN directly. Let p be a packet traveling through the triangle path to the MN (via the HA), and q be the first packet sent via the optimized path to the MN. Packet p is sent from the CN earlier than q is. We derive the probability that packet p arrives at the MN later than packet q does, and validate the analytic model by simulation experiments. Our simulation experiments are extended to investigate how the transmission delay distributions affect the probability of out-of-order delivery. The results provide a guideline in adjusting the routing priority of binding updates to improve the end-to-end network performance.     

一种移动IP的外部代理分层模型--Step-HMIP

现有的移动IP规范存在两个重要的性能问题：(1)通信对端和外地链路上的移动节点之间的三角路由问题;(2)移动节点在紧密耦合的小蜂窝基站间频繁切换时会增加网络负载并加重数据包的丢失．该文针对这两个问题进行研究,给出了一个基于基本移动IP规范的外部代理分层模型——Step-HMIP模型．在此模型中引入了一个新的实体——网关移动代理,用以实现优化路由和平滑切换的功能：在NS上建立了Step-HMIP的仿真模型,对模型的主要参数测试结果表明．Step—HMIP模型在对属地代理(HA)、固定的通信对端(如Web服务器和FTP服务器)和对网络层以上协议无需进行改动的情况下．以小的配置代价就可显著优化路由,降低属地代理的注册负载和稳定了切换时的数据传输率．     

基于HMIPv6自适应路由优化的研究

在层次化移动ipv6协议中，当CN和MN位于同一个MAP域时，两者之间的通信不是优化的路由，可以将MN的链路转交地址通知给CN，实现在移动节点和通信对端之间直接通信，达到路由优化的目的。当移动节点频繁切换时，导致了绑定更新开销的增加。切换频率和数据报传送频率是路由优化研究要考虑的两个重要因素。在权衡考虑MN的切换频率和数据报传送频率的基础上，提出了一种自适应的局部路由优化方案，并分析了该方案的性能。仿真结果表明，在较大的SMR范围内，该方案具有较好的性能。     

Efficient route optimization scheme for nested-NEMO

Network mobility (NEMO) basic support protocol maintains the connectivity when mobile router (MR) of a mobile network changes its point of attachment to the Internet by establishing a bi-directional tunnel between the MR and the home agent (HA). A packet from a correspondent node (CN) traverses through the tunnel to reach the mobile network. Nesting occurs in NEMO when a MR's new attachment point is in another mobile network that has also moved away from its home link. The level of tunneling increases as the level of nesting increases. Multiple levels of tunneling in nested NEMO adds multiple legs to a non-optimized routing path that the IP packets have to traverse in order to reach the final destination. As per our study, an efficient route optimization technique in NEMO, particularly in nested NEMO, is still a research challenge. In this paper, we propose an efficient route optimization scheme for nested NEMO. We use two care-of Addresses for each MR, as well as two types of entries, such as fixed and visiting, in the routing table in each MR. Our route optimization scheme removes the tunnels completely from the nested NEMO in a single step using only one binding update message irrespective of the number of levels in the nest. Our route optimization scheme also works for non-nested NEMO.     

嵌套移动网络中的路由优化研究

针对嵌套移动网络内部节点间通信的乒乓路由问题,提出一种基于绑定更新的路由优化方案。该方案利用绑定更新报文所携带的信息构筑嵌套域内移动路由器的路由信息,实现了嵌套移动网络内部移动路由的功能,有效解决乒乓路由问题,避免由于隧道嵌套而造成的带宽浪费。实验结果表明该方案是可行的。     

A secure and efficient batch binding update scheme for route optimization of nested NEtwork MObility (NEMO) in VANETs

NEtwork MObility (NEMO) is designed to efficiently deal with the mobility of a set of mobile nodes using Mobile Routers (MRs). NEMO is extremely suitable for Vehicle Ad hoc NETworks (VANETs) due to its highly mobile nature. However, NEMO also suffers from some limitations such as inefficient routing paths and multiple tunnels. To solve the problem of inefficient routing paths, there is a growing need for better route optimization. To achieve route optimization in NEMO, when a mobile router moves into a new foreign network, the MR or the mobile nodes within this MR are required to submit binding update messages to the correspondent nodes connecting with the aforementioned mobile nodes. As a result, a popular correspondent node may simultaneously receive a great number of binding update messages within a short period of time. This problem is quickly exacerbated in a nested NEMO environment. In addition, the security issues for route optimization have been widely discussed. Most of the improved schemes adopt traditional signatures to solve the security problems for route optimization, which often leads to heavy computational costs when a large number of signatures need to be verified. In this paper, we propose a Batch Binding Update Scheme (BBUS) to verify multiple signatures at the same time. By the adoption of elliptic curve cryptography, both the computational and communication costs are significantly reduced.     

移动IPv6路由优化模型的性能分析和适应性策略

移动IPv6中为解决三角路由(triangle routing,简称TR)问题,采用路由优化(route optimization,简称RO)作为缺省方案.但是,路由优化在减小路由开销的同时引入了新的信令开销,因此,并非在任何情况下路由优化都优于三角路由.目的是对比在不同网络条件下路由优化和三角路由的开销,提出更有效的适应性路由优化策略.采用数学模型进行分析,引入数据到达率、移动切换率及MN(mobile node)和HA(hone Agent),CN(correspondent node)的位置关系等关键参数,得到分别采用RO和TR的总开销的表达式;引入数据到达率和移动率比值(packet-to-mobility,简称PMR)、节点间距离的关系来权衡数据和信令开销,得到总开销随相关参数变化的数值结果;基于这些分析提出了PMRRO(packet-to-mobility route optimization)适应性路由优化策略:以总开销的最小化为目标,以PMR阈值作为指标,通过适应性调整来决策MN和CN之间的路由选择.模拟验证表明,该策略有比单纯采用TR和RO更好的性能,是为移动管理减少开销、提高效率提出的可行方案.     

A novel mix-based location privacy mechanism in Mobile IPv6

Mobile IP (MIP), a link-layer-independent protocol, is suitable for Internet Protocol (IP) based mobility across homogeneous media as well as heterogeneous networks. Mobile IPv6 (MIPv6) not only possesses the major characteristics of Mobile IPv4 (MIPv4), but also has more advantages such as the expansion of address space and elimination of the “triangle routing”, which make MIPv6 the most suitable candidate for future heterogeneous environment. Location privacy is very important for mobile node (MN) in mobile communications because exposure of the relationship between MN's real physical location and its identity will lead to serious violation of the MN's privacy. And the attackers can easily launch the traffic analysis attack according to such revealed relationship. However, the location privacy of MN to avoid attackers tracing in MIP is not paid more attention up to the present. As the most widely used anonymous communication technology, mix-network can be used to provide the location privacy in MIP. In this paper, we employ the practical mix-network to provide location privacy on signaling control information in MIPv6. By utilizing the practical mix-network, a novel MIPv6 network model is proposed. Based on the network model, a new location privacy extension to MN's home binding and correspondent registration in MIPv6 is proposed and it can be integrated into MIPv6 easily. As a result, our location privacy proposal possesses the benefits succeeded from the adopted practical mix-network, e.g. reducing the trust requirements among the mix servers and increasing the robustness compared with other mix-based MIP location privacy schemes. In addition, the computation load in MN does not increase significantly during the binding procedures according to the analysis, thus it is more suitable for the asymmetric wireless environment.     

基于家乡代理的绑定更新注册验证机制仿真

绑定更新注册是实现移动IPv6的移动性以及移动iPv6路由优化的技术基础,同时又会带来一系列新的安全问题,对移动节点和通信对端之间绑定更新注册验证是解决问题的关键.利用移动节点在业务定制阶段与其家乡代理建立的信任关系和共享密钥,提出一种新的基于家乡代理的绑定更新注册验证机制,并建立了移动iPv6环境下的验证模型和仿真试验系统.在同一仿真平台上,通过与该领域其它研究成果对比分析,在安全性和对路由可达的依赖方面,都优于现有验证机制.突出了家乡代理在绑定更新注册验证过程中的地位和作用,充分利用家乡代理在移动IPv6网络部署中的可控性和可管理性,使得移动IPv6的部署和管理变得更加方便.