WDM光网络的保护和恢复技术

文章概述了IP、SDH和WDM层网络的生存性技术,重点介绍了光传送网的光层生存性技术与光网络恢复技术,还对故障定位、多层生存性机制的协调等问题进行了简单介绍,最后给出了一个业务配置RWA算法与恢复RWA算法的实际方案。     

IP over WDM光网络联合保护策略

随着Internet和网络技术的发展,IP over WDM光网络成为下一代通信网最理想的解决方案。因此,IP over WDM光网络的生存性是下一代通信网成功与否的关键。在传统的保护策略中,IP层和WDM层之间不交换网络的状态信息。探讨了IP层和WDM层保护机制互相协作的必要性,并在通用多协议标签交换GMPLS的基础上,提出了联合保护策略的思想。     

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。     

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GMPLS集成动态多层网络故障恢复技术

基于IP/GMPLS over WDM的网络架构下研究多层网络生存性的协调机制,针对基于GMPLS控制平面的生存性协调方案作了详细的论述.主要从故障检测、故障通知和协调控制等几个方面展开详细的分析研究,该方案能减少恢复故障所需的总时间和,以及可对各层生存性技术进行有效的协调控制.     

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。     

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.     

标签交换光网络

IP对带宽的需求和WDM巨大传输能力的结合要求简化IP与WDM的协议模型。但运营商在传统语音和数据业务的投资使他们不可能在短期内从电路交换网络转移到带宽效率更高的IP/WDM网络上去。WDM技术能够提供多协议支持,彼此独立的不同网络协议可以在网络中共存,现有的、最常用的协议结构是IP/ATM/SDH/WDM（数据业务）和IP/HDLC/PPP/SDH/WDM（电路和专线业务）。目前的数据网络的四个功能层：IP层承载应用程序,ATM层处理流量控制,SDH层管传输,DWDM层提供大量带宽。这种多层叠加网络结构降低了网络效率,增加了网络操作…     

WDM光网及多层网络生存性的研究

为了适应多层次网络发展的需要，在讨论WDM光层生存性机制的基础上，针对多层网络联合的生存性机制进行了仔细的分析，提出了一种多层协调的实现办法，并讨论了多层空闲资源设计中的共享问题。     

WDM光环网的几种保护倒换方案

WDM光网络技术的应用正迅速地提升传输速率与带宽,不断地促进着电信业的发展。WDM光网络的可靠性与生存性变得日益重要。目前的研究热点是在网络的生存性和可重构性方面开发类似于SONET/SDH环网保护的WDM光环网结构,使之具备在经受各种网络故障后能够维持可接受的业务质量的能力。与SDH光环网相比,WDM光环网具有自身的特点：光层的保护与恢复时间比SDH电层快,光层恢复可靠性高,光层恢复成本低,光层保护支持多协议、多业务恢复等等。WDM光网络在传统的传送网络的电通道层和物理层之间引入光层。光层由光通道层、光复用段层…     

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.     

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     

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.     

ATM网络抗毁和自恢复技术研究

基于ATM/MPLS技术的通信网络是承载宽带多媒体业务的综合平台。为了对承载业务进行抗毁保护,对ATM的最基本的1+1、1∶1、m∶n抗毁保护结构进行了研究和总结。同时结合网络传输层,如:PDH、SDH、WDM、MPLS的保护和应用层业务,如:IP、电路交换、以太网和帧中继的抗毁迂回策略,提出了ATM的多层次抗毁自恢复组网结构,为ATM的应用研究提供了借鉴。     

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。     

Logical topology design for IP rerouting: ASONs versus static OTNs

IP-based backbone networks are gradually moving to a network model consisting of high-speed routers that are flexibly interconnected by a mesh of light paths set up by an optical transport network that consists of wavelength division multiplexing (WDM) links and optical cross-connects. In such a model, the generalized MPLS protocol suite could provide the IP centric control plane component that will be used to deliver rapid and dynamic circuit provisioning of end-to-end optical light paths between the routers. This is called an automatic switched optical (transport) network (ASON). An ASON enables reconfiguration of the logical IP topology by setting up and tearing down light paths. This allows to up- or downgrade link capacities during a router failure to the capacities needed by the new routing of the affected traffic. Such survivability against (single) IP router failures is cost-effective, as capacity to the IP layer can be provided flexibly when necessary. We present and investigate a logical topology optimization problem that minimizes the total amount or cost of the needed resources (interfaces, wavelengths, WDM line-systems, amplifiers, etc.) in both the IP and the optical layer. A novel optimization aspect in this problem is the possibility, as a result of the ASON, to reuse the physical resources (like interface cards and WDM line-systems) over the different network states (the failure-free and all the router failure scenarios). We devised a simple optimization strategy to investigate the cost of the ASON approach and compare it with other schemes that survive single router failures.     

Multi-Layer Differentiated Integrated Survivability for Optical Internet

In this paper, we study the problem of multi-layer integrated survivability (MLIS) for efficiently provisioning reliable traffic connections of arbitrary bandwidth granularities in the integrated optical Internet. We decompose the MLIS problem into three sub-problems: survivable strategies design (SSD), spare capacity dimensioning (SCD), and dynamic survivable routing (DSR). First, a review of network survivability in multi-layer IP/WDM networks is provided. Then, multi-layer survivability strategies are proposed and it is observed how these strategies could be applied to the integrated optical Internet architecture. We also present an enhanced integrated shared pool (ISP) method for solving the static MLIS problem (i.e., the SCD sub-problem) and the priority-based integer programming formulations are also given. Moreover, we design a novel scheme called the differentiated integrated survivability algorithm (DISA) to solve the dynamic MLIS problem (i.e., the DSR sub-problem), which employs flexible survivable routing strategies according to the priority of the traffic resilience request. Performance simulation results of DISA show that our adaptive survival schemes perform much better in terms of traffic blocking ratio, spare resource requirement, and average traffic recovery ratio compared with other solutions in the optical Internet.     

智能光网络的多层生存性技术

文章对多层网络生存性问题、独立的网络生存性配置方案和多层网络生存性配置方案进行了概括和分析,对基于IP,GMPLS/Optical智能光网络多层结构的调整策略进行了研究,并讨论了基于智能光网络的统一控制平面、利用层间信令协调机制的集成多层网络生存性方案。