采用多层恢复机制的IP over WDM网络生存性研究

IP over WDM网络是下一代网络的核心,生存性则是保证服务质量(QoS)的关键要素.当网络中出现故障时,选择在IP层还是光层进行保护和恢复是非常重要的课题.文章在论述IP层和光层的保护和恢复机制的基础上,提出了多层联合恢复机制的思想,针对多层联合恢复机制中各层之间如何协调进行了仔细的分析,并提出了自己的见解.     

IP over WDM网络的多层联合恢复策略

由于WDM网络承载着巨大的业务量,其网络可靠性日趋重要.在光层提供生存能力一向具有重要意义,然而由于光层聚集光路径及其粒度较粗的特征,也产生了许多的问题和挑战.MPLS及其扩展MP S的出现,为发展能够协调IP层和光层的联合保护/恢复策略提供了新的方法.鉴于此,文章首先简单介绍了现有MPLS/MP S的恢复机制,然后针对IP over WDM光网络提出了一种联合的二层恢复策略.在这种策略中,光层首先执行恢复动作,如果光层无法恢复所有受损的业务,则上层的IP层接着发起其自身的恢复机制.基于仿真的分析表明,所提出的二层联合恢复策略优于单层的恢复策略;若IP层恢复时具有更好的粒度优势,光层恢复时则具有更高的速度.     

IP光网络设计

系统介绍了 IP组网技术 ,一般地 ,IP光网络设计包括 IP光传送层设计和 IP业务层设计。重点介绍了 IP/ Ethernet over SDH技术、IP over re- configurable WDM技术和 p- cycle恢复技术     

IP over WDM网光层QoS业务映射模型设计

在IP over WDM网络中,WDM光网作为底层传送网络,目前还不能完全解析IP层对业务QoS区分等信息.针对IP和WDM网络中两种不同的QoS机制,应用IP网络差分服务模式,通过UNI接口汇聚来自IP网络的流量,将其映射为光域中相似的业务需求,在光域中为不同QoS业务提供不同QoS保障的光连接通道,实现了WDM网络层的QoS区分服务.     

IP over WDM光网络技术及其实现方案

从光传送网的发展趋势出发,分析了IP over WDM光网络的网络结构和协议规范.讨论了IP over WDM光网络的相关技术,并对分组交换技术进行了较为系统的介绍,最后,为了实现IP over WDM光网络,提出了6MPLS T-MPLS和GMPLS ASON的解决方案.     

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。     

WDM与IP业务的融合

分析了WDM光网络的结构以及联网技术的演进过程，对如何实现IP直接over WDM，发挥WDM光传送网的巨大带宽优势进行了研究，提出了MPLS与GMPLS是解决当前IP层与光层的融合以及跨层管理问题的关键技术。     

在IP/MPLS over WDM网络中基于准入机制的区分服务

在IP over WDM网络中,光层可以通过建立新的光路来为IP层提供带宽.如何利用光层有限的资源使网络服务提供商的利润最大化是流量疏导的一个重要目标.文章基于迭加网络模型,研究IP/MPLS over WDM网络的准入机制,设计算法在不影响整体效率的前提下为网络提供区分服务.     

IP/MPLS-over-WDM的网络生存性

Internet的发展和数据业务的爆炸性增长对当前网络提出了更高的要求。网络将演变为IP/MPLS—over—WDM。对于这种以光网络为基础的网络构架,网络的生存性问题变得尤为重要。本文首先介绍了MPLS网络的生存性机制。由于以数据业务为中心的光网络至少包含IP层和光层,本文提出了几个在多层网络生存性面临的问题,并给出了几种方案。最后,讨论了IP/MPLS—over—WDM特有的生存性思考。     

基于传统WDM平台的保护技术

本文重要介绍了基于传统WDM层的保护技术,以广东省IP over WDM测试情况着重阐述光1＋1通信保护技术的性能指标。     

The interface between IP and WDM and its effect on the cost of survivability

A summary of research on survivable IP networks overlaid over WDM networks is presented. The WDM networks are part of optical transport service providers, who lease lightpath services to institutions with IP networks. The lightpath services realize IP links for IP networks, and they have different protection grades such as unprotected and protected. The research included considering new network survivability requirements and incorporating them into network design problems. The cost of survivable IP over WDM networks is compared over three scenarios. Each succeeding scenario has the WDM network provide more flexible services, and the IP and WDM networks become more integrated. We consider the problem of setting up lightpaths for an IP network so that the network will remain connected after a fiber link fault. Algorithms to find the lightpaths and minimize cost are given. The network costs under the three scenarios are compared by simulations.     

IP/MPLS-Over-WDM网络的生存性

Internet的发展和数据业务的爆炸性增长对当前网络提出了更高的要求。网络将演变为IP/MPLS-over-WDM。对于这种以光网络为基础的网络构架,网络生存性问题变得尤为重要。由于以数据业务为中心的光网络至少包含IP层和光层,笔者提出了几个在多层网络生存性面临的问题,并给出了几种方案。最后,讨论了IP/MPLS--Over-WDM特有的生存性思考。     

下一代IP骨干网的扩展性和生存性探讨

本文首先阐述了解决IP骨干网扩展性和生存性的重要意义,然后分别就下一代IP骨干网的扩展性和生存性的主要技术问题和解决方案进行深入的探讨并提出了若干解决思路,最后简要介绍了中国电信有关下一代IP骨干网的实践和思路.     

Advances in the management and control of optical Internet

Given the ever increasing demand for network bandwidth, and the phenomenal advances in optical wavelength division multiplexing (WDM) networking technologies, a major component of the next generation Internet will be an Internet protocol (IP)-based optical WDM network. As IP over WDM networking technologies mature, a number of important architectural, management and control issues have surfaced. These issues need to be addressed before a true next generation optical Internet can emerge. We enumerate some of the key architectural, management and control issues and discuss corresponding approaches and advances made toward addressing these issues. We first review the different IP/WDM networking architectural models and their tradeoffs. We outline and discuss several management and control issues and corresponding approaches related to the configuration, fault, and performance management of IP over dynamic WDM networks. We present an analysis and supporting simulation results demonstrating the potential benefits of dynamic IP over WDM networks. We then discuss the issues related to IP/WDM traffic engineering in more detail, and present the approach taken in the NGI SuperNet Network Control and Management Project funded by DARPA. In particular, we motivate and present an innovative integrated traffic-engineering framework for reconfigurable IP/WDM networks. It builds on the strength of multiprotocol label switching for fine-grain IP load balancing, and on the strength of reconfigurable WDM networking for reducing the IP network's weighted-hop-distance, and for expanding the bottleneck bandwidth     

IP voer WDM光网络及其生存性问题讨论

本文介绍了IP voer WDM光网络的演进过程与发展趋势；讨论了其生存性问题，包括光层生存性有关概念、分类及各自的优缺点，IP/MPLS层与WDM层联合生存机制的必要性以及这种联合机制需要解决的竞争问题=带宽资源共享问题和失效扩散问题等。     

Single-Fiber Access/Metro WDM Ring Architecture for Asymmetric Traffic Applications in Next Generation Networks

The next generation network (NGN) and the speed-up of access lines will sharply increase the demand for one-way applications such as internet protocol television (IP TV) and video on demand (VOD). One-way applications make the downlink bandwidth much larger than the uplink bandwidth. Asymmetric traffic is best supported by using different numbers of wavelengths in the uplink and downlink, which presumes the use of a wavelength division multiplexing (WDM) network. Unfortunately, the existing 2- or 4-fiber ring network architecture is symmetric, and so it cannot efficiently accommodate asymmetric paths. This paper proposes a novel 1-fiber WDM protection ring that offers a cost-effective optical network architecture for asymmetric traffic as well as symmetric traffic. It also proposes a new 1:1 protection switching scheme and automatic protection switching (APS) control protocol that can reduce capital expenditures for optical-electro-optical termination cards and provide nonrevertive protection switching with extra traffic and APS with end-to-end supervision including optical switching fabrics. Moreover, this paper shows that the proposed wavelength switching scheme offers much better network survivability after multiple wavelength failures than the existing bidirectional switching scheme can offer.     

多层网络中的生存性

未来传输网络中,不同的网络技术(如IP、SDH和WDM技术)的融合需要不同网络层次之间进行有效地配合,特别是网络生存性领域更是如此。首先对多层网络生存性机制的框架以及在多层网络环境下实现网络生存性的技术进行了概述,同时以IP over WDM为例,说明了这些方法的应用方式。     

Integrated Survivability Strategies of IP／GMPLS／Opticai Multi——layer Network

In last decade,due to that the popularity of the internet, data--central traffic kept growing, some emerging networking requirements have been posed on the today‘s telecommunication networks,especially in the area of network survivability. Obviously, as a key networking problem, network reliability will be more and more important. The integration of different technologies such as ATM, SDH, and WDM in multilayer transport networks raises many questions regarding the coordination of the individual network layers.This problem is referred as multilayer network survivability. The integrated multilayer network survivability is investingated as well as the representation of an interworking strategy between different single layer survivability schemes in IP via generalized multiprotocol label switching over ootical netwnrk     

Integrated Survivability Strategies of IP/GMPLS/Optical Multi-layer Network

In last decade,due to that the popularity of the internet, data-central traffic kept growing,some emerging networking requirements have been posed on the todays telecommunication networks,especially in the area of network survivability.Obviously,as a key networking problem,network reliability will be more and more important.The integration of different technologies such as ATM,SDH,and WDM in multilayer transport networks raises many questions regarding the coordination of the individual network layers.This problem is referred as multilayer network survivability.The integrated multilayer network survivability is investingated as well as the representation of an interworking strategy between different single layer survivability schemes in IP via generalized multi-protocol label switching over optical network.