4over6:基于非显式隧道的IPv4 跨越IPv6互联机制

IPv6骨干网正在逐步建成并走向实用,纯IPv6的骨干网(如中国下一代互联网:CNGI)已经出现,而已有的大量互联网应用和服务仍存在于IPv4网络中,因此出现了大规模复杂IPv4网络通过IPv6骨干网互联的需求,然而目前没有满足这种需求的过渡机制.本文提出了一种基于IPv6的IPv4网络互联过渡机制框架,对4over6过渡机制框架进行了阐述和分析,并通过原型系统实现,对4over6机制框架进行了原理和功能验证测试.为减小路由开销,提出了ISP独立部署方案,增强了4over6机制框架的可实施性.4over6过渡机制框架具备对网络和端系统透明性、轻型和可自适应动态选路特性,网络管理维护负担小,可适应于大规模、复杂的网络互联等优点.     

IPv6校园网架构探讨

针对目前IPv6(网际协议版本6)校园网部署方案多为初期阶段的研究问题,文章对IPv4(网际协议版本4)校园网过渡到纯IPv6校园网的各个阶段的架构进行了研究和探讨.通过研究IPv6的基本服务,探讨了以IPv4为主流的IPv6校园网、IPv6/IPv4校园网共存期和纯IPv6校园网等各个阶段可能的校园网架构方案.     

中国联通下一代网络的实践与思考

文章介绍了中国联通的多业务统一网络平台,包括多业务服务质量(QoS)保障的融合的承载平台、融合的软交换核心控制架构、多业务QoS保障的城域综合业务网络和基于IPv6的网络承载技术.依据中国联通在下一代网络(NGN)方面的实践,文章对多业务统一网络平台的先进性、效果与效益进行了总结,并指出了存在的问题.文章指出:由于未来NGN技术将向基于IP多媒体子系统(IMS)的NGN方向继续演进,同时网络承载层技术将逐步从IPv4过渡到IPv6,因此中国联通将积极探索基于IMS的NGN网络架构与组网模式,努力开展面向IPv6的应用实验与推广工作,特别是移动IPv6业务的开发和推进.     

IPv6在MPLS IPv4骨干网上的迁移策略研究

简单介绍了MPLS的基本概念，就IPv6在MPLSIPv4骨干网上的迁移策略进行了深入探讨，给出MPLS网上的各种迁移策略的实现方式。认为：当IPv6网络达到一定的规模，并且相应的IPv6数据流达到一定数量级时，运营商就可以考虑采用文中所讨论的技术实现IPv6的部署。     

A performance study for IPv4–IPv6 translation in IP multimedia core network subsystem

A Next Generation Network (NGN) is an advanced, packet‐based network that exploits broadband and QoS‐enabled transport technologies for enabling multimedia services. In NGNs, the principles and requirements of IP Multimedia Sub‐system (IMS), which are used to deliver the desired benefits, should be carefully examined and studied. Internet Protocol version 6 (IPv6) is adopted by Third‐generation Partnership Project (3GPP) to solve address storage problem and provide new features (e.g. plug‐and‐play and mobility) for IMS. However, in the early stage of IPv6 deployment, the existing Voice‐over‐IP (VoIP) networks support Internet Protocol version 4 (IPv4) only. For IPv4–IPv6 interworking between IMS and the existing VoIP networks, the IMS‐Application Level Gateway (IMS‐ALG) and the Transition Gateway (TrGW) are proposed to translate Session Initiation Protocol (SIP) and Real‐time Transport Protocol (RTP) packets, respectively. In this paper, we focus on the IPv4–IPv6 translation for RTP packets, which is the bottleneck of VoIP performance. Specifically, we developed a TrGW called National Information and Communications Initiative (NICI)‐TrGW. In NICI‐TrGW, we perform IPv4–IPv6 translation at the Linux kernel and adjust the header room of kernel‐level packet buffer for each packet to reduce memory‐copy operations. We evaluate the performance of NICI‐TrGW and the existing solutions by using the SmartBits. Our study indicates that NICI‐TrGW outperforms the existing solutions in terms of three different output measures including packet loss rate, maximum throughput, and average latency. Copyright © 2009 John Wiley & Sons, Ltd.     

IPv6网络与业务演进策略分析

随着IPv4地址的加速消耗,IPv4网络和业务向IPv6过渡已经势成必然,但在向IPv6演进的过程中,存在IPv6内容源缺乏,IPv4/IPv6互通困难,网络设备对IPv6支持程度参差不齐等各种问题。电信运营商必须结合自身网络和业务特点,选择合适的过渡技术和策略,平滑地向IPv6演进。本文首先简要介绍各种IPv6过渡技术,然后从电信运营商的角度,分析对比网络和业务向IPv6演进的各种策略,并指出演进过程中存在的一些困难以及解决办法。     

Multi‐step solution for QoS management in wireless mesh networks

Wireless mesh networks (WMNs) as community‐ and city‐wide type networks are required to extend their capability to offer real‐time multimedia services. While technologies exist to support quality of service (QoS) at node level, we propose here a network‐wide multi‐step solution to manage and offer QoS across a WMN. From a provider perspective, the provisioning and fulfillment of QoS‐based services fall under the realms of service management, network and traffic engineering functions. We describe the relevant functions required to design, implement and operate a WMN for providing a qualitative QoS to end‐users. Our proposed solution considers network planning aspects, including node placement, node clustering and frequency assignments, route discovery between ingress–egress points and appropriate QoS provisioning across the network. Route‐level QoS provisioning is defined as the process of allocating resources to the nodes along the identified routes to meet a priori known aggregated traffic demands in order to satisfy the QoS requirements for different types of application. Simulation and experimental tests are conducted to validate the correct behavior of processes/algorithms and to access the solution in achieving QoS for aggregate user traffic. Copyright © 2012 John Wiley & Sons, Ltd.     

IPv6 on DSL: the best way to develop always-on services

The deployment of IPv6 has become an issue of strategic importance for many economies, and telecom operators and ISPs play a key role in ensuring the availability of this new protocol on broadband access networks. It cannot be denied that the complexities exist in deploying IPv6 in an IPv4 world. Knowing this, telecom operators and ISPs have to ensure a viable transition strategy that takes into account transparent interoperability and mature integrated functionalities for deploying advanced applications on both IPv4 and IPv6. This potent combination will enable operators and ISPs to exploit the richer services offered by IPv6 while interoperating IPv4 during this long transition period, creating a new business model that will generate return on investment without waiting for the whole world to be fully IPv6 deployed. Only the use of IPv6 at the end-user site can drive differentiated services, achieving returns in not only investments, but also in services innovation and flexible communication solutions. So both IPv4 and IPv6 protocols have now to be implemented on digital subscriber line access networks. Solutions are mature and are beginning to be deployed.     

Layer 3 VPN Services over IPv6 Backbone Networks: Requirements, Technology, and Standardization Efforts

Layer 3 virtual private networks (L3VFN) enable organizations to connect geographically dispersed sites to one another across the packet switched network of a service provider. The most popular form of L3VPN is based on BGP/MPLS (border gateway protocol/multiprotocol label switching) technology in which the service provider offers a network-based IP VPN routing and forwarding service to its customers across its own IPv4-based MPLS backbone network. With the deployment of IPv6-based backbone networks underway, there is an emerging requirement to support these same L3VPN services across a native IPv6 backbone network. This introduces a requirement to provide routing and tunneling of IPv6 VPN (and IPv4 VPN) packets across an IPv6 backbone network. Softwires is an Internet Engineering Task Force (IETF) Working Group chartered to address the requirement of providing a generalized, network-based, multi-address family, IP routing and tunneling capability across native IP backbone networks pursuant to IPv6 transitions. Elements of the softwires work can form the basis of an L3VPN over IPv6 solution. After providing a brief overview of how L3VPN works in various topologies, this article presents the requirements for L3VPN services over an IPv6 backbone network and discusses a possible solution set that builds over the softwire technology and related IETF standards. Finally, we outline future directions and how the softwire technology can support new services and improved scalability     

MPLS: the magic behind the myths [multiprotocol label switching]

This article reviews the key differences between traditional IP routing and the emerging multiprotocol label switching (MPLS) approach, and identifies where MPLS adds value to IP networking. In various corners of the industry MPLS has been held up as the solution to IP QoS, gigabit forwarding, network scaling, and traffic engineering. Each of these expectations is critically considered in the light of developments in conventional gigabit IP routers. It is shown that MPLS adds the ability to forward packets over arbitrary non-shortest paths, and emulate high-speed “tunnels” between IP-only domains-capabilities critical to service providers who need to better manage resources around their backbones, or who are planning IP VPN services. However, it is also argued that the technology required to support IP QoS and gigabit forwarding is not unique to MPLS. A network of gigabit IP routers or switches may be entirely sufficient for QoS and performance if traffic engineering is not a requirement     

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。     

Network architecture and medium access control for deploying third generation (3G) wireless systems over CATV networks

We propose a novel and cost‐effective approach for the deployment of third generation (3G) wireless systems over hybrid fiber coaxial (HFC) CATV networks. The main goal is to facilitate 3G deployment over the existing CATV plant and reduce the large cost required for building a dedicated last mile infrastructure for 3G access networks. Our proposal reduces the last mile cost by sharing the existing CATV network and using the standard equipment and protocols of data‐over‐cable systems interface specifications (DOCSIS). This allows rapid deployment of 3G wireless systems, facilitates convergence of wireless and wireline networks and paves the way towards all IP wireless networks. Enhancements to the DOCSIS medium access control (MAC) protocol must be implemented in order to support Quality of Service (QoS) guarantees for 3G data and signaling traffic. This paper presents the proposed 3G over CATV network architecture and DOCSIS medium access control (MAC) enhancements for enabling the support of QoS guarantees for 3G data and signaling traffic. The proposed MAC enhancements can reduce the access delay for delay‐sensitive traffic by 30 to 40% over existing DOCSIS MAC without compromising QoS guarantees for other traffic classes, or the DOCSIS channel utilization. Copyright © 2004 John Wiley & Sons, Ltd.     

组建IPv6核心网络的方案探讨

随着基于IPv6协议的下一代互联网(NGI)在中国逐渐开始部署,如何组建电信级IPv6核心网成为运营商关注的重要问题.本文首先提出了IP核心网络演进的原则,然后分别介绍和分析了IPv6网络的多种互通与过渡技术,并列举了国外运营商IPv6核心网络的演进方案,最后给出了总体实施建议.     

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.     

Implementation of IPv6 services over a GMPLS-based IP/optical network

In recent days, there has been considerable interest in deploying IPv6-based services. Trial and commercial IPv6 services offering has already begun, especially in Japan, Korea, China, and other parts of the world. At the same time, many service providers have embraced MPLS as the enabler for the required multiservice capabilities of their next-generation packet networks. Also, the widespread deployment of DWDM-based optical transport systems in the core network to satisfy the tremendous need and increase in capacity demand has led network planners to reconsider traditional approaches to provisioning and network restoration, and plan integration of the optical layer into the MPLS infrastructure according to the emerging GMPLS technology. The purpose of this article is to discuss next-generation network architecture evolution and present a detailed architecture for transport of emerging IPv6 services and applications over next-generation GMPLS multiservice backbone networks. This article also presents an implementation and demonstration of this technique for IPv6 transport over a GMPLS backbone network as well as interoperability verification of IPv6 and GMPLS using a GMPLS network testbed.     

虚拟化和可重构的CGN技术助力IPv6平滑过渡

为解决网络向IPv6演进过程中CGN设备的灵活性和可适应性的问题,文章提供一种虚拟化和可重构的CGN技术方案,通过通用的硬件和灵活的软件架构,实现CGN设备的灵活和可重构,满足网络向IPv6过渡的部署需要。     

运营商网络IPv6演进的策略分析

本文首先分析了IPv6引入的必要性,以及IPv4和IPv6网络在相当长的时间内必然共存的事实,介绍了IPv4向IPv6演进和共存的各种机制,并就运营商网络的IPv6演进策略,做了简要的探讨.     

Evolutionary gaming approach for decision making of Tier‐3 Internet service provider networks migration to SoDIP6 networks

With the increasing number of Internet of Things (IoT) devices, current networking world is suffering in terms of management and operations with lack of IPv4 addresses leading to issues like network address translation (NAT) proliferation, security and quality of services. Software‐defined networking (SDN) and Internet Protocol version 6 (IPv6) are the new networking paradigms evolved to address related issues of legacy IPv4 networking. To adapt with global competitive environment and avoid all existing issues in legacy networking system, network service providers have to migrate their networks into IPv6 and SDN‐enabled networks. But immediate transformations of existing network are not viable due to several factors like higher cost of migration, lack of technical human resources, lack of standards and protocols during transitions, and many more. In this paper, we present the migration analysis for proper decision making of network transition in terms of customer demand, traffic engineering, and organizational strength with operation expenditure for network migration using evolutionary gaming approach. Joint migration to SDN‐enabled IPv6 network from game theoretic perspective is modeled and is validated using numerical results obtained from simulations. Our empirical analysis shows the evolutionary process of network migration while different internal and external factors in the organization affect the overall migration. Evolutionary game in migration planning is supportive in decision making for service providers to develop suitable strategy for their network migration. The proposed approach for migration decision making is mostly applicable to fairly sustained service providers who lack economics, regulation/policy, and resources strengths.     

IPv6 integration and coexistence strategies for next-generation networks

IPv6 has been designed, among other things, to provide an expanded address space to satisfy the future networking requirements. In this article, we analyze and discuss important aspects of IPv6 deployment scenarios, and propose the system architecture coexisting and integrating with IPv4/MPLS networks. We investigate on various IPv6 deployment strategies along with network design examples, comparing these techniques. Then the IPv6 deployment in service provider environments is proposed.     

在CNGIIPv6上建立诚信安全的P2P环境和分布管理系统

文章指出中国为实施中国下一代互联网(CNGI)计划而大规模布设IPv6骨干网,这为发展P2P应用、建立诚信安全具有分布管理能力的P2P网络环境提供了机会:一方面在CNGI的IPv6网上一开始就可以实行实名制,从而发展建立网络新秩序;另外一方面可以在CNGI上以无缝和持续演进的方式建立智能结点重叠网,以支持P2P应用并提供分布式管理.文章认为CNGI发展的IPv6终端和IPv6用户网(如家庭网、传感器网等)可以通过在现有IPv4有线/无线接入网和城域网中建立IPv6隧道连接到IPv6骨干网P2P平台,以获得足够的通达能力,并在此基础上发展基于P2P的各种新应用.