基于PNNI的ASON路由协议

通用多协议标签交换(GMPLS )是将多协议标签交换 /流量工程(MPLS-TE )进行光网络扩展,并被广泛接受作为自动交换光网络(ASON )控制面协议的理想选择,然而标准化组织正讨论研究将专用网网间接口( PNNI )协议用于 ASON 控制面的潜力。文中主要通过对 PNNI 的路由分层概念、 PNNI 的路由信息分发机制和 PNNI 的路径选择机制的介绍,给出 PNNI 路由的几个扩展,以适合 ASON 的路由需求。     

智能OXC在ASON中的应用

IP与光技术的融合要求底层光网络具有高度的灵活性和可扩展性，产生了全新的ASON（自动交换光网络），智能OXC（光交叉连接）设备是ASON中的最关键的设备。文中简单介绍了智能自动交换光网络的概念、网络结构，详细分析了ASON中智能OXC矩阵硬件结构和OXC控制平面信令路由功能，最后讨论了智能OXC相关协议及扩展的GMPLS技术。智能OXC强大的光交换能力结合智能信息路由协议，必将与现有网络融合向全智能光网络发展。     

GMPLS and ASON for automatic switched transport networks

In automatic switched transport networks (ASTN), transport services of different granularity can be set up, modified and released on demand, using mechanisms in the control plane. Currently, this novel provisioning paradigm is being standardized under the umbrella of the automatic switched optical network (ASON) and the generalized multiprotocol label switching (GMPLS) framework. This paper gives an overview of the concepts and open issues of ASON and GMPLS at the current stage of their development.     

ASON and GMPLS—Overview and Comparison

In automatic switched transport networks (ASTN), transport services of different granularity can be set up, modified and released on demand using the mechanisms in the control plane. Currently, this novel provisioning paradigm is being standardized under the umbrella of the automatic switched optical network (ASON) and generalized multiprotocol label switching (GMPLS) framework. This paper provides an overview of the ASON and GMPLS frameworks at the current stage of their development and aims in particular on comparing the concepts and pointing out some open issues. In this context, we first give a brief overview of ASON and GMPLS work, and then provide a concept and functionality mapping including network resource models, control plane architecture, discovery, call and control management, and resiliency. Finally we address some important provider requirements.     

ASON控制平面和链路管理协议

随着网络容量的不断扩大,提高核心网络效率和动态分配网络带宽的需求越来越迫切。智能光网络是未来光网络的发展方向,控制平面是实现智能光网络的核心。自动交换光网络(ASON )引入了通用多协议标签交换( GMPLS )控制平面,其中链路管理协议是为管理流量工程链路(TE link)开发的新技术。文中介绍了 ASON 中 GMPLS 控制平面及其主要功能,在此基础上对其中链路管理协议的 4 种基本功能(控制信道管理、链路属性关联、链路连通性验证及故障管理)进行具体分析。     

自动交换光网络控制平面中的GMPLS管理器

自动交换光网络(ASON)指的是直接由控制系统下达信令来完成光网络连接自动交换的新型网络,它赋予了原本单纯传送业务的底层光网以自动交换的智能,它的具体实现要依靠通用的多协议标签交换(GMPLS)协议。首先对ASON和GMPLS技术作了一个简单介绍,然后说明了GMPLS控制平面的软件结构,最后重点分析了ASON控制平面中的GMPLS管理器功能及应用。     

Recovery of the control plane after failures in ASON/GMPLS networks

A reliable control plane plays a crucial role in creating high-level services in the next-generation transport network based on the generalized multiprotocol label switching (GMPLS) or automatically switched optical networks (ASON) model. Approaches to control-plane survivability, based on protection, and restoration mechanisms, are examined. Procedures for the control plane state recovery are discussed, including link and node failure recovery.     

下一代光传送网ASON

提出当今解决光传送网所面临问题的方法,是采用既能低成本建网又能智能化完成交换连接的自动交换光网络( ASON );介绍回顾了光传送网 ASON 技术的产生和取得的成果,以及 ASON 中几种关键控制平面技术的发展情况;阐述了 ASON 控制平面与传统传送网的本质区别、管理平面智能化管理特点所带来的 3 种优点,以及传送平面中光交叉连接( OXC )的 6 种主要交换结构、发展方向和存在的主要问题;最后综述了新一代基于数字同步系列(SDH )提供多种业务、集成传输、交换和路由功能的多业务传送平台(MSTP )技术,并描述其新功能和远期目标。     

自动交换光网络管理平面技术

自动交换光网络(ASON)技术是当前光网络领域研究的热点技术，但是有关ASON管理平面的研究工作和标准化才刚刚起步。本根据下一代光网络向自动交换光网络发展的趋势．介绍了与之相适应的ASON管理平面技术。本阐述了管理平面在ASON体系结构中的作用。ASON网络管理技术的新特点，重点介绍了ASON网络管理的体系结构、管理功能需求以及管理平面的接口和协议，最后结合国内外有关ASON管理平面技术的研究进展。介绍了ASON管理平面的标准化现状和未来发展．     

Topics in Optical Communications - Operational Evaluation of ASON/GMPLS Interdomain Capability over a JGN II Network Testbed

Traffic engineering in backbone networks is an important issue in supporting an appropriate QoS level to accommodate various types of traffic flows efficiently. Automatically switched optical networks and generalized multiprotocol label switching control planes are promising functionalities to achieve the sophisticated mechanism of interdomain traffic engineering. In this article we address dynamic operational scenarios to control IP traffic flows using the ASON/GMPLS control plane. This includes cut-through IP/MPLS routers and the rerouting of failed links through the tunnel of optical label-switched paths. This article presents an operational evaluation of traffic engineering. More specifically, we present QoS recovery for protecting high priority traffic using policy controllers and fault recovery of inter-domain LSPs over the JGN II network testbed. This article evaluates and discusses the feasibility of these operational scenarios using state-of-the-art optical switching and control- plane technologies.     

ASON体系结构的研究

介绍了自动交换光网络的层次结构和广义多协议标记交换协议,讨论了自动光交换网络中的关键技术及实现方法。     

Service differentiation in IP/MPLS over ASON/GMPLS networks

There is a general agreement that the future infrastructure for broadband communications will consist of Automatically Switched Optical Networks (ASONs) controlled by the Generalized Multi-Protocol Label Switching (GMPLS) control plane. Due to the convergence of most services on the Internet Protocol (IP) layer, ASON/GMPLS networks need to provide transport for a variety of applications having different Quality of Service (QoS) requirements. This implies that the Differentiated Service paradigm, which improves the QoS in pure IP networks, needs to be extended to the new underlying infrastructure. This article proposes and compares three schemes for the service differentiation in IP/MPLS over ASON/GMPLS networks. Simulation results demonstrate that a fair trade-off between QoS and resource utilization is achieved when combining routing policy differentiation (RPD), virtual topology differentiation (VTD), and virtual topology sharing (VTS) techniques. The RPD technique decides on the multilayer routing policy to apply depending on the Class of Service (CoS). The VTD technique transports different CoS over different independent virtual topologies. The VTS technique introduces a certain degree of resource sharing among the different virtual topologies.     

On managing optical services in future control-plane-enabled IP/WDM networks

This paper presents the design and experimental implementation of a service-oriented Internet Protocol (IP)/wavelength division multiplexing (WDM) management plane. In the proposed approach, compliant with International Telecommunication Union Telecommunication Standardization Sector (ITU-T)'s automatic-switched optical network (ASON), a distributed control plane performs signaling, routing, and discovery functions, and a decentralized management plane, both at information and architectural levels, performs cross-plane actions to enforce service establishment and monitoring with a view to guarantee service level agreements (SLAs). In-service monitoring provides status of optical resources and services by using spectral- and time-domain information. Some performance aspects of the approach are evaluated in a real testbed featuring dense wavelength multiplexing and a control plane based on the Internet Engineering Task Force (IETF)'s generalized multiprotocol label switching (GMPLS).     

自动交换光网络中的呼叫和连接控制管理

本主要讨论了自动交换光网络中分布式呼叫和连接控制管理。中概述了ITU-T、IETF和OIF在呼叫和连接控制方面的最新进展，包括ITU-T对于呼叫和连接控制的标准化工作情况、IETF对于信令协议的标准化情况、OIF在UNI和NNI接口信令协议方面的进展。此外，还介绍了自动交换光网络中最基本的呼叫过程和连接过程，最后，本重点论述了在引入MESH网恢复情况下的呼叫和连接建立和释放过程。     

ASON信令技术的研究

文章分析了ASON信令体系结构，对ATM论坛提出的PNNI／Q.2931和GMPLS信令协议在ASON的分布式呼叫和连接管理中的应用进行了详细的探讨。     

一种新型的ASON安全组播信令协议

针对自动变换光网络组播信令过程中存在的安全威胁,提出了一种高效的基于GMPLS RSVP-TE的安全组播信令协议。该协议采用P2MP(point-to-multipoint)信令模型,通过数字签名和消息反馈等安全机制,对信令消息中的不变对象和重要可变对象实施保护。考虑到组播成员的动态变化特性,采用高效的组密钥管理策略保证组通信的前向安全性和后向安全性。经仿真实验及分析表明,该协议在保证安全建立组播树的同时,取得了较好的连接阻塞性能和较低的密钥更新时延。     

Waveband grooming and IP aggregation in optical networks

An automatically switched optical network (ASON) can be used as the transport layer of generalized multiprotocol label switching (GMPLS) networks. The design of an ASON involves determining the number of optical cross-connects (OXC) in the network, the required number of ports per OXC, and the interconnection topology of the OXCs. Given the number of ports per OXC, we present a linear algorithm to find the number of OXCs and to identify a cost-effective topology. We then develop a scheme that can be used to perform waveband grooming for several different topologies of an ASON that uses single-layer multigranular OXCs. We identify the bottlenecks and investigate the effect of traffic grooming schemes in the design of an ASON as a function of the peak access rate per customer. We evaluate the topologies and architectures for a national trunk network.     

光网络的统一控制信令

光网络统一控制平面的出现使得光网络的发展进入了一个灵活、智能、自动交换的新阶段。对光网络的统一控制平面的关键信令技术GMPLS进行了全面分析,包括GMPLS扩展的协议结构、GMPLS增强的标记格式等,尤其对GMPLS信令的双向通路连接建立过程进行了详细的分析。最后给出了实现GMPLS控制功能的结构框架。     

基于GMPLS的智能光网络流量工程研究

自动交换光网络已经成为下一代光网络的发展方向,而其控制平面的分布式连接管理功能则是实现光网络智能性的关键。本文介绍了自动交换光网络的功能结构,在此基础上系统论述了分布式连接管理的功能要求,详细分析了分布式的呼叫和连接处理的实现过程,并给出了具体的参考流程和状态转移模型。     

自动交换光网络中光电子器件的进展

光网络正在向高速大容量、良好的扩展性和智能化的方向发展。自动交换光网络的出现是光传送网技术的重要突破,光电子器件功能的增强与性能的提高将对其实现与发展起决定性作用。本文介绍了自动交换光网络中一些光电子器件的重要特性和发展趋势。