一种新型光因特网体系结构技术研究

通过对光因特网体系结构的分析研究，提出了一种新型混合模型网络结构，其典型特点为：在光节点设备上采用一个信令转换机制，使其同时具有重叠模型和对等模型光节点的功能，实现一个核心光网络与不同模型网络的互连，并且管理平面能够对控制平面实行有效的监控和管理．模拟仿真结果表明此技术是有效的．     

基于对等模型的新型光因特网技术

文章简述一种新的组网技术———对等模型,它为光因特网的实现提供一种新的方式。通用多协议标签交换(GMPLS)支持对等模型网络,GMPLS技术和路由机制是构建对等模型光因特网的关键技术。     

构建对等模型光因特网的路由技术研究

以光因特网对等模型拓扑结构为基础,重点介绍了对等模型下的路由协议与路由机制。     

信令转换函数实现不同网络模型间的互联

通过在核心光节点中加入信令转换函数的方法,实现了不同网络模型之间的互联,在这种新的机制下,混合网络中的对等客户、重叠客户之间可以自由进行连接和通信,这对于网络互联技术的发展以及网络运营商都具有积极意义。     

光因特网体系结构与模型分析

在分别支持单跳连接和多跳连接的核心光网络的条件下,对光因特网的体系结构进行了分析和讨论,比较了各种不同的互联模型,对网络建设具有一定的指导意义。     

IP智能与WDM技术的融合

讨论了在IP over WDM directly分层结构下,IP层网络与光层网络的三种基本融合方式—静态重叠模型、动态重叠模型和动态对等模型,这三种融合方式体现了IP over WDM directly的演变过程。同时还对各种融合方式中网络的组成结构及相应的控制平面技术作了详尽的阐述。     

光因特网中的网络管理

近年来，随着Internet的出现和繁荣，IP业务量呈现爆炸式的增长，同时，wDM由于其巨大的带宽和成熟的技术正成为未来的主导传输技术。因此，人们提出了光因特网的概念来将IP和wDM两种技术有效结合起来。随着光因特网概念的提出，光因特网中的控制和管理技术也得到了广泛的研究，不过当前的研究主要集中于对控制技术的研究。但是，当前控制平面方法还有很多问题有待解决，同时，要满足这个新型网络最重要的要求即实现业务的快速提供和故障恢复，采用管理平面的方法也同样可以实现。光因特网网络管理不仅要能够对IP网和光网络进行管理，还要能够对两种技术进行集成的管理，以更好地利用和维护网络资源。本主要研究光因特网中的网络管理技术，提出了光因特网管理模型、管理体系结构以及管理信息模型，并对光因特网中管理信道的实现进行了研究。     

基于GMPLS对等模型的智能光网络QoS模型设计

介绍了智能光网络层叠模型和对等模型的特点,简要分析了智能光网络的QoS机制,提出了一种基于GMPLS对等模型的智能光网络QoS模型,通过对此模型下的数据业务的时延、链路的利用率进行仿真,验证了所设计的QoS模型的优越性和可行性.     

光突发交换试验网的可行性分析

文章对光突发交换网络的产生背景、光突发交换网络模型及技术实现的可行性,以及进一步发展光突发交换网络需要关注的核心技术予以分析,最后对建设中国下一代高速光因特网提出一些建议与思考。     

基于私有云信任度量的对等网络节点安全互联模型

在缺乏必要信任关系的对等网络环境中,节点的安全互联对系统的稳定运行具有重要意义.针对对等网络存在的信任缺陷,借助私有云平台在计算与存储过程中的高效性、安全性等特点,提出一种私有云协助的对等网络信任度量模型.该模型基于主观逻辑理论对连接过程中的节点可信度进行度量,针对网络环境中存在的低质量服务、节点虚假推荐及策略性欺骗等问题开展研究,提出了应对机制.实验仿真结果表明,提出的模型具有较好的可行性、有效性和动态适应性.     

An Enquiry-Based Dynamic Service Provisioning Approach for Overlay IP-over-Optical Networks

Network control for IP-over-optical networks can be classified as falling under the overlay, augmented, or peer models. In the first two models, the IP layer and the optical layer only have the resource information of their respective layers. In the peer model, all the resource information is known to both layers; hence, it can potentially achieve better resource utilization. Unfortunately, the peer model approach is generally not acceptable to the operators if the IP layer and optical layer belong to two different administrations. In addition, it is much more complex and generally seen as not feasible in the near future In this paper, we propose an enquiry-based provisioning scheme based on the overlay model which can, however, utilize resources in both layers as in the peer model approach. Two simple and novel algorithms for routing labeled-switched path (LSP) requests for this provisioning scheme are proposed. Simulation results show that our proposed algorithms perform significantly better than other routing algorithms for the overlay model and are nearly as good as the integrated routing algorithm for the peer model.     

Performance Comparison of Overlay and Peer Models in IP/MPLS over Optical Networks

We study the connection establishment of label switched paths (LSPs), and compare the LSP blocking performance of the overlay and peer models in IP/MPLS over optical networks. We consider two dynamic routing algorithms for the establishment of LSP connections, of which one is for the overlay model and the other is for the peer model. Our investigations on two typical network topologies, namely NSFNET and ARPA2 networks, show that the number of add/drop ports (or transceivers) on optical cross-connects (OXCs) has a significant impact on the LSP blocking performance for both models. We show by computer simulation that in each case, there is a threshold value for the add/drop ratio, which can achieve almost the best blocking performance. This threshold value remains virtually unchanged as the traffic load varies, but it does depend on the network topology and the number of wavelengths per fiber. This will then indicate the number of add/drop ports to be used so that one can achieve a near optimal blocking performance without incurring unnecessarily excessive network costs. Our investigations reveal that the peer model achieves a much better blocking performance than the overlay model when the number of add/drop ports is relatively high, but that this is not always true when the number of add/drop ports is small.     

On the Issues in Implementing the Peer Model in Integrated Optical Networks

This paper contributes to a much-needed understanding of the operation, design, implementation, and evaluation of the peer model in integrated optical networks. The overlay and peer models of operation form the two fundamental architectural alternatives for interworking the control planes of optical TDM/WDM networks with those of packet or cell-based networks. Of these, the overlay model is well understood, having a precedence in IP-over-ATM networks deployed in the mid 1990s. It follows a proven approach to managing multi-area, multi-domain networks. The peer model, on the other hand, has not been implemented yet, and has also not been analyzed adequately in the literature. To enable service providers to implement either model, based on the respective merits of each, it is fundamentally important to develop a working solution for the peer model. The focus of this paper is to provide such a solution, perform a complexity analysis of the solution, and discuss its impact on the design of the protocols and the packet and transport layer devices that must interwork to realize this model.     

UP2P: a peer-to-peer overlay architecture for ubiquitous communications and networking

Approaches to building an intelligent consumerfriendly network have evolved over time from centralized switch-based to router- and serverbased Internet architectures. We propose to drive this evolution further with a new highly scalable architecture that provides features to users derived from the computational and networking capabilities of very large populations of sophisticated terminals. This architecture relies on emerging peer-to-peer overlay technology. We describe a peer-to-peer overlay design that addresses requirements crucial for consumer applications, including overlay federation, peer heterogeneity, peer mobility, and service discovery. In addition, we introduce the concept of an overlay operator and describe the requirements for managed overlays. We have designed and implemented both a middleware and a peer-topeer platform that illustrates these concepts.     

Exploring the accuracy of capturing snapshots in large‐scale P2P IPTV systems

With the growing maturity of peer‐to‐peer (P2P) technology, Internet protocol television (IPTV) applications based on that gained great success commercially and have attracted more and more attentions from both industry and academia. Currently, the active measurement method based on crawler technology is the most popular and effective one to study P2P IPTV systems. Existing measurement results revealed that accuracy of captured overlay snapshots depends on the crawling speed of crawler system. In order to capture more accurate overlay snapshots of P2P IPTV system, we developed a very fast and efficient distributed crawler system using the distributed architecture and peer degree‐rank mechanism. In this paper, we first introduce the architectures of PPTV channel‐list resource distribution and the whole system, which is the most popular and largest instance of P2P IPTV applications nowadays. Subsequently, this paper evaluates the crawling results of two dedicated crawlers capturing from peer‐list servers and ordinary peers, respectively. Finally, we propose a fast and accurate dedicated crawler system based on distributed architecture and peer degree rank for PPTV. The experiment results show that the performance of our distributed crawler system is much better than other existing crawler systems. Specifically, our distributed crawler can track a very popular channel with about 7200 online users in 30 s. It is also reasonable to believe that our distributed crawler system can capture complete overlay snapshots. To the best of our knowledge, our study work is the first to explore capturing accurate overlay snapshots of large‐scale P2P IPTV applications. Our crawler system can provide a good solution for capturing more accurate overlay snapshots of PPTV system and can also be used to help researchers to design crawler systems for other P2P IPTV systems. Copyright © 2015 John Wiley & Sons, Ltd.     

下一代光因特网体系结构的选择与比较

下一代光因特网(NGOI)体系结构的基本特征是两层(业务层和传送层)和三个平面(数据平面、控制平面、管理平面)。分析和归纳了四种主流的面向下一代光因特网体系结构模型。提出了一种基于通用多协议标记交换(GMPLS)技术和光电混合交换技术的集成光因特网模型,该模型与其它模型相比较,结合了光电两个领域的技术优势,具有网络综合性能高,容易实现,扩展性好等优点。     

传统VPN与MPLS VPN对VPN网络可扩展性的比较

基于IP的虚拟专用网络（VPN）正逐步成为未来基于IP网络传送各种服务的基础，许多的SP在他们的VPN传输网络中提供各种增值应用。在过去多年的发展中，总共有不同的VPN模型被建议：覆盖模型（基于加密隧道技术的VPN）和对等模型（基于MPLS的VPN）。文中主要对两种模型的VPN技术作一简单的介绍并且对他们的可扩展性进行比较，从理论上得出结论：基于MPLS的VPN有着非常优良的可扩充性，就可扩充性而言是未来VPN服务中最有前途的一种。     

On the Placement of Infrastructure Overlay Nodes

Overlay routing has emerged as a promising approach to improving performance and reliability of Internet paths. To fully realize the potential of overlay routing under the constraints of deployment costs in terms of hardware, network connectivity and human effort, it is critical to carefully place infrastructure overlay nodes to balance the tradeoff between performance and resource constraints. In this paper, we investigate approaches to perform intelligent placement of overlay nodes to facilitate (i) resilient routing and (ii) TCP performance improvement. We formulate objective functions to capture application behavior: reliability and TCP performance, and develop several placement algorithms, which offer a wide range of tradeoffs in complexity and required knowledge of the client-server location and traffic load. Using simulations on synthetic and real Internet topologies, and PlanetLab experiments, we demonstrate the effectiveness of the placement algorithms and objective functions developed, respectively. We conclude that a hybrid approach combining greedy and random approaches provides the best tradeoff between computational efficiency and accuracy. We also uncover the fundamental challenge in simultaneously optimizing for reliability and TCP performance, and propose a simple unified algorithm to achieve both.      

Real-Time Streaming Relay Mechanism for P2P Conferences on Hierarchical Overlay Networks

A peer-to-peer (P2P) multimedia conferencing service is operating that users share their resources to each other on the Internet. It can solve the problem in the centralized conferencing architecture, such as the centralized loading, single point error, and expensive infrastructure. However, P2P networks have the problem that a peer has a difference between the physical location and logical location in the overlay network. In the viewpoint of P2P networks, the nearest conference resource may be far away geographically. The P2P-session initiation protocol (P2P-SIP) multimedia conference is to construct an application-based logical multicast network efficiently according to physical network information. Thus, this paper proposes a real-time streaming relay mechanism for P2P conferences on hierarchical overlay networks. The real-time streaming relay mechanism can improve the transportation efficiency of conferencing stream exchange well based on the application-layer multicast (ALM) structure and the hierarchical overlay networks.