移动IPv6网络中的QoS及其实现探讨

由于移动环境的特殊性，使得在移动网络中提供服务质量（QoS）变得非常复杂。文章首先分析了基于RSVP的移动IPv6QoS解决方案，然后引入了一种新的IP通用信令体系——NSIS，并讨论了NSIS在移动IPv6网络QoS中的应用。     

一种改进的支持无线IP网络的资源预留协议

移动IP技术能够支持基于IP的无线网络,资源预留协议(RSVP)用来保证多媒体传输的服务质量。然而把现有的RSVP应用于移动IP网络就会存在许多问题。提出了一种改进的RSVP支持方案(ERSVP)来实现无线IP网络的服务质量保证。ERSVP在分层网络中结合了MRSVP和RSVP隧道技术。根据性能分析,ERSVP方案能够获得比MRSVP较少的信令延迟、信令负载和资源耗费。     

下一代互联网IPv6能力的开发

文章介绍了以IPv6为核心技术的下一代互联网在IPv6的地址管理、服务质量扩展、集成的安全特性、对移动性的支持等方面的功能特点,并针对现在电信运营中方兴未艾的虚拟专用网(VPN)业务,探讨了IPv6技术下VPN的实现.文章认为采用IPv6技术不仅会促进数据通信市场发展,还会促进以话音通信为主的固定通信和移动通信市场,产生新的以娱乐和教育为主的视频通信服务市场以及信息家电连网服务市场,IPv6技术会为电信运营业带来广阔的市场前景.     

流标签在基于IPV6的下一代互联网的应用研究

IPv6协议对IP网络服务质量提供了很好的支持,它定义了流标签字段帮助实现服务质量(Qo S)控制,但是如何设计和部署IPv6流标签还是一个开放的研究课题。介绍了IPv6流标签的概念,描述了IPv6流标签的处理过程,分析了IPv6流标签的结构设计方案,最后探讨了基于IPv6流标签的Qo S控制机制在应用与实现中面临的问题。     

基于IPv6的AAA系统的设计与实现

随着网络技术和网络服务的飞速发展,以及网络复杂性的不断增加,要求AAA体系结构能够在IPv6网络中提供安全和灵活的服务.提出了一种基于IPv6的可支持多种接入终端的AAA方案,该方案基于802.11i协议和Diameter协议,使用策略实现对不同接入终端的访问控制,并为Diameter协议提出了一些新的属性.文中讨论了系统的设计和实现,并分析了安全性.系统具有很强的可扩展性,支持用户漫游机制,为IPv6网络提供了灵活、安全的AAA服务.     

对于IPv6网络中服务质量的研究

随着Internet的迅速发展,新型的网络应用对QoS的需求日益迫切,为了使网络能够支持已有的和新出现的多媒体服务与应用,保证通信与服务质量,让网络运营商控制网络资源及其使用,对于QoS的研究越来越重要。首先介绍QoS的相关概念,然后比较IPv4和IPv6对于服务质量的不同支持并具体研究IPv6下对于支持QoS机制的改进。     

基于BIERv6技术的大视频网络承载研究与应用

近年来国家陆续出台IPv6相关政策文件,推动IPv6服务能力提升,鼓励建立IPv6应用新生态。基于IPv6的BIERv6具备协议简化、去MPLS和支持IPv6等优点,结合大视频网络承载技术能够扩大组播应用并且为运营商降本增效,本研究主要从IPTV以及视频流媒体两个业务场景入手,实践推广BIERv6技术的应用场景,并在新型城域网中试点基于BIERv6技术的大视频网络承载方案,验证BIERv6主要功能,为后续规模推广提供实战经验,同时加速倒逼推进老旧终端设备的升级替换,解决老旧终端升级替换“堵点”问题,打造终端及应用IPv6+新生态。     

嵌入式IPv6网络视频终端

介绍了以Intel XScale处理器PXA270为核心的嵌入式系统平台,分析了IPv6组播与流媒体协议原理,移植了对IPv6有良好支持的Linux操作系统及Qtopia嵌入式图形系统.在此基础上,针对上述嵌入式系统移植和优化开放源代码的优秀媒体播放器MPlayer,实现了支持IPv6组播与流媒体传输的嵌入式IPv6网络视频终端.随后对该视频终端的媒体播放性能进行了测试与分析,并搭建了移动IPv6试验床,通过与IPv6网络流媒体服务器联机验证了视频终端功能.     

支持RSVP安全性的Policy系统的研究与实现

由于宽带和多媒体技术在不断发展，基于Policy系统实现对网络服务质量的监管，得到越来越多的研究与应用；但是它对服务质量的安全性的监管还不能令人满意，这也对其进一步应用与实施提出了严峻挑战。在支持RSVP的Policy系统基础上，本文提出通过增加支持RSVP安全性的规则实现其安全性，并且详细给出其设计原则以及这类规则的结构和内容，并论述了其在Policy系统中关键性设备－－PEP、PDP的具体实现。     

基于IPv6的QoS控制组播路由机制

设计并实现了一种基于IPv6的QoS(quality of service)控制组播路由机制.基于启发式单播路由协议,修改了PIM-SSM协议与MLD协议,实现了IPv6下启发式源特定组播.为提供QoS控制,扩展了RSVP协议,设计了分层组播流量控制机制,基于博弈分析确定为用户预留的带宽量,优化网络提供方与用户方效用.开发了该机制的原型系统并进行了大量试验,结果表明该机制具有良好的性能,能够提供IPv6下的QoS控制组播路由.     

移动IPv6环境中集成RSVP信令机制

本文针对在移动无线IP网络中运行RSVP信令协议存在的问题，提出了一种把RSVP信令集成于Ipv6数据包头扩展字段的方案，以减少切换过程中资源预留路径建立的时间，为移动节点提供了服务质量保障。并将此方案和原始RSVP方案在资源预留时间和信令负荷方面进行了性能比较。     

充满活力的下一代网络技术--RSVP

近年来，随着经济的发展和计算机的普及，Internet业务出现了爆炸性的增长，并且出现了许多新兴的业务，如IP电、话、视频点播、视频会议等，现有Internet只提供传统单一尽力传送（best—effort）业务，因而急需新的网络协议以支持未来分类业务所需的不同带宽和服务质量（QoS）保障，现有网络虽然可以通过ATM（Asynchronous Transfer Mode）来解决QoS问题。但由于ATM信元的开销在整个帧中占了30％，严重降低了网络的传输效率，故未来网络不可能使用它。新出现的RSVP（资源预留协议）根据其自身的特点，必然会替代ATM，成为下一代网络保证QoS的关键网络技术。下面详细介绍RSVP的特点以及它如何有效的与未来的IPv6相结合。     

Mobility protocols and RSVP performance in wireless IPv6 networks: shortcomings and solutions

Resource reservation protocol (RSVP) is a network‐control protocol used to guarantee Quality‐of‐Service (QoS) requirements for real‐time applications such as Voice‐over‐IP (VoIP) or Video‐over‐IP (VIP). However, RSVP was designed for end‐systems whose IP addresses do not change. Once mobility of an end‐system is allowed, the dynamically changing mobile IP address inevitably impacts on RSVP performance. Our study aims to first quantify the significance of this impact, and then propose a modified RSVP mechanism that provides improved performance during handoffs. Our simulations reveal that the deployment of standard RSVP over Mobile IPv6 (MIPv6) does not yield a satisfactory result, particularly in the case of VIP traffic. Fast Handovers for Mobile IPv6 (FMIPv6) was found to be providing the best performance in all tested scenarios, followed by Hierarchical Mobile IPv6 (HMIPv6) with a single exception: during low handoff rates with VoIP traffic, MIPv6 outperformed HMIPv6. We then designed a new RSVP mechanism, and tested it against standard RSVP. We found that the proposed approach provides a significant improvement of 54.1% in the Total Interruption in QoS (TI_QoS) when deployed over a MIPv6 wireless network. For HMIPv6, performance depended primarily on the number of hierarchical levels in the network, with no improvement in TI_QoS for single‐level hierarchy and up to 37% for a 5‐level hierarchy. FMIPv6 on the other hand, provided no room for improvement due to pre‐handoff signaling and the tunneling mechanism used to ensure a mobile node (MN)'s connectivity during a handoff, regardless of the RSVP mechanism used. Copyright © 2007 John Wiley & Sons, Ltd.     

Internet protocols for multimedia communications. II. Resourcereservation, transport, and application protocols

Part I (ibid., July-Oct. 1997) surveyed the evolution of Internet protocols and applications and described the Internet protocol IPv6 in detail. This part discusses new developments at the upper layers that support real-time Internet multimedia, such as audio and video conferencing and shared whiteboard applications. Application-level framing (ALF), proposed in 1990 for protocol and application design, now forms the basis for many new Internet protocols and applications, including Real-time Transport Protocol (RTP) and Mbone multimedia applications. RTP supports real-time applications that adapt to changing network situations to maintain the quality of service (QoS). The Resource Reservation Protocol (RSVP) provides new Internet services with higher quality than best-effort by means of resource reservations     

Multicast for RSVP switching: An extended multicast model with QoS for label swapping in an IP over ATM environment

The ubiquity of IP associated with the acknowledgment of ATM as a key switching technology has motivated an increasing interest towards the design of a more efficient way of operating IP over ATM networks. This approach is known under the name Label Swapping. A few studies have addressed the primary issue of providing simultaneously quality of service and multicast. We propose a solution where we mix an RSVP architecture with one Label Swapping technique called IP Switching. We discuss problems that arise when using cut-through associated with an RSVP multicast model and propose an application for an IPv6 environment over an ATM switching hardware.     

Fast RSVP: Efficient RSVP Mobility Support for Mobile IPv6

In recent years, with the development of mobile communication technologies and the increase of available wireless transmission bandwidth, deploying multimedia services in next generation mobile IPv6 networks has become an inevitable trend. RSVP (resource reservation protocol) proposed by the IETF is designed for hardwired and fixed networks and can not be used in mobile environments. This paper proposes a protocol, called Fast RSVP, to reserve resources for mobile IPv6. The protocol adopts a cross-layer design approach where two modules (RSVP module and Mobile IPv6 module) at different layers cooperate with each other. Fast RSVP divides a handover process with QoS guarantees into two stages: (1) setup of the resource reservation neighbor tunnel and (2) resource reservation on the optimized route. It can help a mobile node realize fast handover with QoS guarantees as well as avoid resource wasting by triangular routes, advanced reservations and duplicate reservations. In addition, fast RSVP reserves “guard channels” for handover sessions, thus greatly reducing the handover session forced termination rate while maintaining high performance of the network. Based on extensive performance analysis and simulations, Fast RSVP, compared with existing methods of resource reservation in mobile environments, performs better in terms of packet delay and throughput during handover, QoS recovery time after handover, resource reservation cost, handover session forced termination rate and overall session completion rate.     

IPv6互联网协议的特点分析

为了具体阐述IPv6的具体内容和特点,以及它与IPv4之间的主要差别,本文将从地址机制、服务质量和网络安全性等方面对IPv6协议进行较深入的分析,从中可以看到IPv6能较好地解决IPv4所面临的主要问题,将进一步推动互联网的发展。     

IPv4/IPv6综合组网关键技术研究

对新一代互联网协议IPv6在地址空间、移动性、安全性以及服务质量等方面的技术特点进行了综合分析。深入探讨了IPv4/IPv6综合组网主要运用的双协议栈、隧道和翻译等几种关键技术,并从使用场合、兼容性和实现的方便性等方面对这些技术进行了分析比较,提出了过渡时期IPv4/IPv6综合组网的策略建议。对当前IPv4向IPv6演进的研究与实践具有较好的参考价值。     

RSVP在数字视频网络传输中的应用研究

数字视频网络的广泛应用,要求实时性传输中IP能够提供足够的带宽、较高的优先级以及较低的包丢失率,为此,Internet工程任务组(IETF)开发了一套用于因特网的综合服务协议和标准,通过RSVP来管理网络资源分配以提供不同级别的服务,讨论怎样将该协议与典型的数字视频网络传输方案相结合,使现有支持QoS的网络可以达到更为稳定流畅的传输效果.     

RSVP Extensions for Real-Time Services in Hierarchical Mobile IPv6

The Mobile IPv6 (MIPv6) provides many great features, such as sufficient addressing space, mobility, and security; MIPv6 is one of the most important protocols for next generation mobile Internet. Simultaneously, with the rapid improvement of wireless technologies, the real-time multi-media IP services such as video on demand, videoconference, interactive games, IP telephony and video IP phone will be delivered in the near future. Thus, to furnish accurate QoS for real-time services is one of the most important thing in the next generation mobile Internet. Although RSVP, which is a resource reservation protocol, processes signaling messages to establish QoS paths between senders and receivers, RSVP was originally designed for stationary networks and not aware of the mobility of MNs. Therefore, this paper proposes a novel RSVP extension to support real-time services in Hierarchical Mobile IPv6 (HMIPv6) environments. For intra-site mobility, the concept of QoS Agent (QA) is proposed to handle the RSVP QoS update messages and provide the advanced reservation models for real-time services. For inter-site mobility, IP multicast can help to invite inter-site QAs to make pre-reservation and minimize the service disruption caused by re-routing the data path during handover. Simulation results show that the proposed scheme over HMIPv6 is more suitable for real-time services than the famous RSVP tunnel-based solution.