Impact of ipv4-ipv6 coexistence in cloud virtualization environment

Since January 2011, the IPv4 address space has been exhausted and IPv6 is taking up the place as its successor. Coexistence of IPv4 and IPv6 bears problem of incompatibility, as IPv6 and IPv4 headers are different from each other, thus, they cannot interoperate with each other directly. The IPv6 transitioning techniques are still not mature, causing hindrance in the deployment of IPv6 and development of next generation Internet. Until IPv6 completely takes over from IPv4, they will both coexist. For IPv4–IPv6 coexistence, the following three solutions are possible: (a) making every device dual stack, (b) translation, or (c) tunneling. Tunneling stands out as the best possible solution. Among the IPv6 tunneling techniques, this paper evaluates the impact of three recent IPv6 tunneling techniques: 6to4, Teredo, and ISATAP, in cloud virtualization environment. In virtual networks, these protocols were implemented on Microsoft Windows (MS Windows 7 and MS Windows Server 2008) and Linux operating system. Each protocol was implemented on the virtual network. UDP audio streaming, video streaming and ICMP-ping traffic was run. Multiple runs of traffic were routed over the setup for each protocol. The average of the data was taken to generate graphs and final results. The performance of these tunneling techniques has been evaluated on eight parameters, namely: throughput, end to end delay, jitter, round trip time, tunneling overhead, tunnel setup delay, query delay, and auxiliary devices required. This evaluation shows the impact of IPv4–IPv6 coexistence in virtualization environment for cloud computing.     

Characterizing user‐perceived impairment events using end‐to‐end measurements

Measures of quality of service (QoS) must correlate to end‐user experience. For multimedia services, these metrics should focus on the phenomena that are observable by the end‐user. Metrics such as delay and loss may have little direct meaning to the end‐user because knowledge of specific coding and/or adaptive techniques is required to translate delay and loss to the user‐perceived performance. Impairment events, as defined in this paper, are observable by the end‐users independent of coding, adaptive playout or packet loss concealment techniques employed by their multimedia applications. Time between impairments and duration of impairments are metrics that are easily understandable by a network user. Methods to detect these impairment events using end‐to‐end measurements are developed here. In addition, techniques to identify Layer 2 route changes and congestion events using end‐to‐end measurements are also developed. These are useful in determining what caused the impairments. End‐to‐end measurements were conducted for about 26 days on 9 different node pairs to evaluate the developed techniques. Impairments occurred at a high rate on the two paths on which congestion events were detected. On these two paths, congestion occurred for 6–8 hours during the day on weekdays. Impairments caused by route changes were rare but lasted for several minutes. Copyright © 2005 John Wiley & Sons, Ltd.     

IPv6 over IPv4隧道技术原理与实现

从IPv4(Internet Protocol Version4)到IPv6的过渡是一个复杂的过程，针对IPv4到IPv6的转换问题已有很多解决方案。文中详尽讨论了在IPv6部署初期所采用的关键技术——IPv6 over IPv4隧道技术的原理，并逐一对比分析了目前主流的5种IPv6 over IPv4隧道技术（手工配置隧道、IPv4 GRE(generic routing encpsulation)隧道、隧道代理、自动配置隧道、6to4隧道）的机理、实现方式以及应用场合。     

An efficient mobile IPv6 handover scheme

Excellent handover performance is essential for deploying real time applications over wireless Internets. In this paper, this study present a novel handover scheme for Mobile IPv6. The proposed scheme is based on an infrastructure, which is called Cross-layer Address Resolution (CAR). A smart message interaction for the Binding Update procedure is also introduced. The prototype is illustrated first and a buffering approach adopted to achieve zero packet loss. The proposed scheme, which is called Seamless Handover for Mobile IPv6 (S-MIPv6), evolved from Fast Handover for Mobile IPv6 (F-MIPv6). The problems in F-MIPv6, such as triangle route and sequence disorder, are solved by the proposed scheme. The S-MIPv6 avoids building tunnels and reduces registration delay. It is capable of cooperating with a Mobility Anchor Point (MAP) to take advantage from hierarchical networks. The S-MIPv6 is modeled and simulated. In a practical case, the disruption duration is close to the Data Link layer handover latency (50–100 ms). We believe that the proposed S-MIPv6 is capable of providing seamless handover for time critical services.     

快速层次移动IPv6切换性能分析及优化

移动IPv6技术中切换延时对实时应用影响很大。介绍了目前移动IPv6常用的快速移动和层次移动切换技术,描述其切换原理和过程。结合2种技术的优缺点,给出了一种新的快速层次移动IPv6的切换方案。利用NS-2对这3种切换方法进行仿真得到的结果表明,快速层次移动IPv6切换延时要小于快速移动IPv6和层次移动IPv6的切换延时,且降低了数据包丢失率,提高了网络的性能。     

A Model‐Based Analysis of Secure Video Transmission Based on IPSec and IPv4

A promising solution to protect wired Internet networks is to use the Secure Internet Protocol (IPSec); however, this has some drawbacks, particularly on the quality of service (QoS). This paper aims at evaluating the video traffic QoS in terms of end‐to‐end delay and packet loss rate. Based on some basic assumptions, our analysis shows that the performance with IPSec is rapidly inferior to the IPv4 performance. We thus suggest adding some QoS parameters into IPSec in order to achieve a compromise between QoS and security.     

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.     

Enabling novel premium service classes in DiffServ over MPLS‐enabled network

Network resources dimensioning and traffic engineering influence the quality in provisioned services required by the Expedited Forwarding (EF) traffic in production networks established through DiffServ over MPLS‐enabled network. By modeling EF traffic flows and the excess of network resources reserved for it, we derive the range of delay values which are required to support these flows at DiffServ nodes. This enables us to develop an end‐to‐end (e2e) delay budget‐partitioning mechanism and traffic‐engineering techniques within a framework for supporting new premium QoS levels, which are differentiated based on e2e delay, jitter and loss. This framework enables ingress routers to control EF traffic flow admission and select appropriate routing paths, with the goal of EF traffic balancing, avoiding traffic congestion and getting the most use out of the available network resources through traffic engineering. As a result, this framework should enable Internet service providers to provide three performance levels of EF service class to their customers provided that their network is DiffServ MPLS TE aware. Copyright © 2008 John Wiley & Sons, Ltd.     

一种IPv6隧道环境下数据逃逸的防御策略

隧道技术是IPv4向IPv6过渡阶段的重要研究内容,为无IPv6物理接入的用户提供基于隧道的IPv6接入,使其可提前使用IPv6网络。为提高隧道网络的安全性,对隧道流量有关安全设备的影响进行了研究。指出隧道技术可被攻击者利用实施针对网络边界安全设备的数据逃逸,攻击网络内部主机。因此,提出了基于隧道分类的防御方法,通过在特定结构中增加外层包头的相关信息对不同流量进行分类,抵御上述攻击。实验表明,该方法具有较好的时间和空间复杂度,对系统负载影响较小。     

An opportunistic cross‐layer architecture for voice in multi‐hop wireless LANs

We propose an opportunistic cross‐layer architecture for adaptive support of Voice over IP in multi‐hop wireless LANs. As opposed to providing high call quality, we target emergencies where it is important to communicate, even if at low quality, no matter the harshness of the network conditions. With the importance of delay on voice quality in mind, we select adaptation parameters that control the ratio of real‐time traffic load to available bandwidth. This is achieved in two ways: minimizing the load and maximizing the bandwidth. The PHY/MAC interaction improves the use of the spectral resources by opportunistically exploiting rate‐control and packet bursts, while the MAC/application interaction controls the demand per source through voice compression. The objective is to maximize the number of calls admitted that satisfy the end‐to‐end delay budget. The performance of the protocol is studied extensively in the ns‐2 network simulator. Results indicate that call quality degrades as load increases and overlonger paths, and a larger packet size improves performance. For long paths having low‐quality channels, forward error correction, header compression, and relaxing the delay budget of the system are required to maintain call admission and quality. The proposed adaptive protocol achieves high performance improvements over the traditional, non‐adaptive approach. Copyright © 2008 John Wiley & Sons, Ltd.     

Impact of Redhat IPv6 router on heterogeneous host connections

Internet's popularity has been expanding on dramatic pace and the number of people getting connected to it multiplies regularly. With this high demand, the current Internet Protocol (IPv4) has reached its limits. The next generation Internet Protocol version6 (IPv6) has been incorporated into various operating systems. The motivation behind this work is how well IPv6 co‐operates with various operating systems. The performance of the IP stack, together with the behaviour of the OS greatly affects the efficiency of network applications built on top of it. The acceptance of IPv6 implementations on various operating systems heavily relies on the end‐user performance. In this paper, we propose to analyse these various IPv6 implementations for its host and router‐level supports. In this paper, we investigate the impact of Redhat‐based IPv6 router on IPv6 stacks of three different operating systems namely, Windows2003, Redhat Linux 9.0 (Redhat9.0) and FreeBSD4.9. Copyright © 2006 John Wiley & Sons, Ltd.     

All‐IPv6 service interworking gateway

Improvements of inter‐operability, interface IP and dual mobility function must be investigated to move toward full IP and seamless multimedia applications. An All‐IPv6 service architecture that consists of cellular systems and Wireless LAN networks has been constructed. A GPRS/WLAN interworking gateway with an IPv6 facility has been designed and its performance examined in terms of queue length, system throughput, loss rate and delay. The results of the simulation of a 1 Mbps WLAN and 144 kbps GPRS interworking system show that: (1) the queue length is directly proportional to the traffic load (the length increases to 100 packets in 61 seconds at a rate of increase of around 50% per 30 seconds); (2) if the size of the queue is increased to 100 packets, then the loss rate declines to 0.017, (a longer queue corresponds to a lower loss rate); (3) the size of the queue only weakly influences the system throughput when the queue length is increased; and (4) the average delay is approximately 0.83 second/bit, when the queue size is 100 packets. The delay doubles as the queue size doubles. Copyright © 2005 John Wiley & Sons, Ltd.     

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.     

IPv6隧道代理设计实现中的关键问题研究

隧道技术应用于IPv4向IPv6过渡时期.手动隧道在大规模网络中难以配置和管理,采用隧道代理技术可以实现隧道自动管理,使得网络提供商可以为用户提供早期的IPv6接入服务.兰州理工大学IPv6试验床在Linux平台下,利用PHP技术自主设计开发了隧道代理系统,并对RFC3053提供的隧道代理基本模型进行了改进和细化.本文对其进行了介绍并阐述了隧道代理系统设计实现中的关键问题.     

Improving Mobile IPv6 handover and authentication in wireless network with E‐HCF

Mobile IP allows a mobile node to maintain a continuous connectivity to the Internet when moving from one access point to another. However, due to the link switching delay and to Mobile IP handover operations, packets designated to mobile nodes can be delayed or lost during the handover period. Moreover, every time a new attach point is confirmed, the mobile node, its home agent and its corresponding node must be authenticated mutually. This paper presents a new control function called Extended Handover Control Function (E‐HCF) in order to improve handover performance and authentication in the context of Mobile IPv6 over wireless networks. With an analytical model and some OPNET simulations, we show in this paper that our solution allows provision of low latency, low packet loss and mutual authentication to the standard handover of Mobile IPv6. Copyright © 2009 John Wiley & Sons, Ltd.     

Hierarchical and low‐power IPv6 address configuration for wireless sensor networks

The paper proposes a hierarchical and low‐power IPv6‐address configuration scheme for wireless sensor networks based on the cluster‐tree architecture. In the scheme, a wireless sensor network is divided into multiple clusters and the generation algorithm of a cluster is proposed. A cluster‐tree architecture for wireless sensor networks is presented and a layered IPv6 address format for a cluster head and a cluster member is created. The stateless address configuration strategy and the stateful address configuration strategy are effectively combined to develop the IPv6 address configuration scheme. In the scheme, the duplicate address detection of the IPv6 address assigned for a cluster member is performed in the cluster where the cluster member locates, and the IPv6 address configuration for the cluster members in the different clusters can be carried out at the same time. The paper also addresses the mobility of sensor nodes and their failure. From the theoretical and simulative perspectives, the paper analyzes the performance parameters, including duplicate address detection cost, address configuration cost and address configuration delay time, of the proposed scheme, Strong DAD and MANETConf. Analytical and simulative results show that the performance of the proposed scheme is better. Copyright © 2011 John Wiley & Sons, Ltd.     

移动IPv6路由优化性能分析

用NS-2.1b6＋Mobiwan进行仿真实验,给出了移动IPv6三角路由和优化路由之间的性能比较分析。在仿真实验中,检测了移动节点在广域IPv6网移动时通信对端节点和移动节点之间的端到端分组时延。实验结果表明,移动IPv6优化路由的性能明显优于三角路由。     

QoS experiences in native IPv6 networks

Deployment of IPv6 technology in research and commercial networks has accelerated in the last few years. Inevitably, as more advanced services take advantage of the new technology, IPv6 traffic gradually increases. Today, there is limited experience in the deployment of Quality of Service (QoS) for IPv6 traffic in backbone networks that support the Differentiated Services framework. As available software and hardware are designed to handle IPv4 packets, there is a need to accurately measure and validate performance of QoS mechanisms in an IPv6 environment. This paper discusses tests and technical challenges in the deployment of IPv6 QoS in core networks, namely the production dual stack gigabit‐speed Greek Research and Education Network (GRNET) and the IPv6‐only 6NET European test network, using both hardware and software platforms. In either case, we succeeded in delivering advanced transport services to IPv6 traffic and provided different performance guarantees to portions of traffic. The deployed QoS schema was common to IPv6 and IPv4; in most cases both v4 and v6 traffic exhibited comparable performance per class, while imposing no significantly different overhead on network elements. A major conclusion of our tests is that the IPv6 QoS mechanisms are efficiently supported with state‐of‐the‐art router cards at gigabit speeds. Copyright © 2008 John Wiley & Sons, Ltd.     

IPv6的实现工具

IPv6具有很多IPv4所不具备的优点,由IPv4转换一到IPv6是Internet发展的需要,文章对混合堆栈机制,隧道技术以及NAT－PT等实现IPv6的工具进行了分析,虽然有一些故障影响了IPv6的实现,但IPv仍然大有前途。     

移动IPv6切换时延优化新方法

移动IPv6中,移动节点(MN)在不同子网间移动时,既不中断与通信对端(CN)的通信,也不用改变其本身的IP地址.但是当MN与其家乡代理(HA)之间相距较远时,移动IPv6切换时延较大,对于实时性要求较高的业务无法适用.本文分析比较了目前移动IPv6常用的切换时延优化方法,提出了一种自适应快速层次移动IPv6切换时延优化方法,减小了移动IPv6切换时延,提高了网络的性能.