基于RSVP-TE的组播信令协议在ASON中的实现

讨论了自动交换光网络中实现组播的意义,介绍了GMPLS框架下基于RSVP-TE信令协议做出的组播扩展.在实验网络环境里完成了组播信令协议的实现并成功进行了组播树的建立、嫁接、剪枝和删除等操作.     

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。     

ASON控制平面探究

本文主要针对自动交换光网络ASON的核心部分一控制平面进行研究.从ASON的结构切入,论证了控制平面的引入是ASON具有智能性的必要条件.GMPLS技术作为最易于实现控制平而的方法,讨论了RSVP-TE中LSP的连接、删除和状态刷新.对GMPLS生存机制中故障LSP的4中恢复方式的通道建立及恢复时间进行了分析和比较,从而得出资源预留综合考虑下是现阶段最优的恢复方式的结论,并对单点故障时各恢复方式在连接影响和业务丢失率方面进行相互比较,突出预置重路由的特点:恢复速度快,网络恢复能力的可预见性好.     

扩展RSVP-TE的路由排除策略

在实际应用中，以IP网为基础的通用多协议标签交换（GMPLS）控制平面的可靠性尚不能满足自动交换光网络（ASON）电信级的要求，针对这一情况，文章主要探讨了GMPLS信令RSVP-TE的扩展，为建立保护光通道实现路由排除功能，对排除路由对象（XRO，Exclude Route Object）和显示排除路由对象（EXRS，Explicit Exclude Route Subobject）两个对象进行了扩展。     

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。     

通用多协议标签交换技术研究

通用多协议标签交换技术(GMPLS)在光交换网中具有广阔的应用前景,但对它的研究还不够深入.首先指出GMPLS与传统的标签交换技术(MPLS)在7个方面的区别,然后刻画GMPLS光网络的一般结构,对特点进行了分析,指出光IP包交换的实质是光标记的转发与交换.设计了GMPLS光网络的技术方案,对关键技术进行分析,提出了一...     

基于GMPLS协议的ASON试验平台

文章介绍了清华大学自主研发的基于通用多协议标签交换(GMPLS)协议的自动交换光网络(ASON)试验平台.试验平台由3个层面构成,分别为传送层面、控制层面和管理层面.传送层面由4个光交叉连接(OXC)和1个光上下路复用器(OADM)构成的传送网络组成;控制平面由多个协议模块构成,包括链路管理、路由和信令模块,这些协议的实现都是基于互联网工程任务小组(IETF)的GMPLS协议开发和实现的;管理平面完成配置管理和故障管理,包括网元管理以及软永久连接的触发等.试验平台支持动态可配置的网络拓扑、自动邻居发现、受限路由以及光层快速的保护和恢复功能.     

下一代光网络组网技术--GMPLS

通用多协议标记交换(GMPLS)是MPLS向光网络扩展的必然产物,它为了适应对智能光网络进行动态控制和传送信令的要求而对传统的MPLS进行了扩展、更新。使用GMPLS可以为用户动态地提供网络资源,以及实现网络的保护和恢复功能。本文首先介绍了GMPLS的主要内容,接着对GMPLS和MPLS进行了比较,最后阐述了GMPLS在智能光网络控制平面的应用。     

RSVP-TE在自动交换光网络中的应用研究

根据ASON的要求,在对GMPLS RSVP-TE信令协议做进一步扩展的基础上,给出了把呼叫和连接功能分离进行处理的完整流程,提出了一种对已有连接进行重新路由的简单有效的方法。     

LMP在自动交换光网络中的应用研究

通用多协议标签交换（GMPLS）是目前公认的实现ASON网络控制平面的核心协议簇。链路管理协议（LMP）是GMPLS中专门负责网络节点之间所有链路资源的管理部分。文中详细介绍了LMP协议的内容与功能,重点分析了其在光网络中的重要应用,并通过网络编程仿真说明了其链路管理过程。     

用于Mesh光网络快速保护恢复的GMPLS信令机制的扩展

分析了Mesh光网络保护机制和恢复机制,并对GMPLS信令机制进行了扩展,给出了扩展后实现保护恢复的协议格式和信令流程,最后依据实验数据给出扩展的GMPLS信令机制的保护、恢复时间的仿真结果.     

RETRACTED ARTICLE: Research on Energy Saving Design of Intelligent Building Based on Genetic Algorithm

Generalized Multiprotocol Label Switching (GMPLS) networks is capable of allocating suitable route based on the size of the network and computational constraints. In this paper, we propose a connection provisioning strategy for updating the Traffic Engineering Database of Path Computation Element (PCE) in GMPLS optical networks. Control and management plane are used for resource optimization in PCE-based centralized network. We have also proposed connection provisioning for Label Switched Path (LSP) to optimize the resources and to maximize the connection establishment. For provisioning a connection with LSP requests, we have formulated the Integer Linear Programming and constraints to minimize the blocking of connections and network performance. The results obtained shows that the proposed strategy has better network resource utilization with minimum blocking of connections.     

Accounting for Shared Regenerators in GMPLS-Controlled Translucent Optical Networks

In translucent optical networks, the usage of sparse opto-electronic regenerators permits to overcome optical signal quality degradations. In dynamic translucent optical networks, where lightpaths are established upon request, regenerators can be effectively time shared. However, the current generalized multiprotocol label switching (GMPLS) protocol suite does not consider how to dynamically reserve and release shared regenerators and how to distribute regenerator availability information to network nodes. In this paper, four Translucent Lightpath Dynamic Provisioning (TLDP) schemes are proposed to establish lightpaths in dynamic distributed translucent optical networks. TLDP schemes differently combine the utilization of specific open shortest path first-traffic engineering (OSPF-TE) or resource reservation protocol-traffic engineering (RSVP-TE) extensions and shared regenerator availability information. Simulation results show that TLDP scheme based on OSPF-TE extensions obtains lower lightpath setup time, but higher control plane load than TLDP schemes based on RSVP-TE extensions. Moreover, schemes based on RSVP-TE extensions or on OSPF-TE extensions obtain the same lowest blocking probability.      

Impact of GMPLS Control Message Loss

GMPLS is typically viewed as an attractive control plane for optical networks. Motivated by a desire to investigate the impact of control plane faults on the data plane, the impact of losing messages from the key GMPLS protocols, OSPF-TE and RSVP-TE, is studied in this paper. A number of configurations of both protocols are compared in a range of scenarios, with the impact of control message loss assessed by evaluating the efficacy of the control plane in establishing and maintaining data plane connections and the overhead incurred in doing so.      

Signaling and Control Procedures Using Generalized MPLS Protocol for IP over an Optical Network

This paper reviews the existing research activities on signaling and control procedures for IP over optical networks. We focus on the IP‐centric signaling and control architecture based on the generalized multi‐protocol label switching (GMPLS) protocol and analyze various scenarios and technical issues for deploying the IP over an optical network. We analyze the signaling and operations and administration and maintenance requirements for integrating an IP network and an optical network in order to cope with the high bandwidth and poor resource granularity of the optical network, including the optical cross‐connect system. On the basis of network architecture and a reference configuration model, we investigate the GMPLS‐based control architecture and interconnection model appropriate for controlling IP bandwidth and optical lambda resources. The signaling and control procedure based on GMPLS on optical user‐network interface and network‐network interface are comparatively investigated to provide the optical lightpath. We also study protection and restoration procedures to protect link failure when it applies to GMPLS signaling.     

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。     

An experimental switching-aware GMPLS-based lightpath provisioning protocol in wavelength-routed networks

In wavelength-routed optical networks, the high-delay introduced by the optical switching fabric for resource reservation increases critically the lightpath setup delay. In order to minimize the setup delay, Generalized Multi-protocol Label Switching (GMPLS) introduced the concept of Suggested Label Object (SL), which allows to start reserving and configuring the hardware with a proposed wavelength from the source node to the destination node. This solution is not optimal in wavelength selective networks (WSN) (i.e., without wavelengths converters). The need of guaranteeing the wavelength continuity constraint for end-to-end optical connections, combined with the lack of global wavelength-based link information (the source node is not aware of which wavelengths are available on each link), makes that the likelihood of establishing a lightpath using the proposed suggested label may be minimum. In this article, we propose an enhancement to the current GMPLS RSVP-TE signaling protocol with offset time-based provisioning that minimizes the lightpath setup, improving the overall network performance in terms of blocking probability and setup delay. Experimental performance evaluation has been carried out in ADRENALINE testbed, a GMPLS-based intelligent all-optical transport network.     

一种基于折回点重路由的折回机制在ASON中的应用

该文提出了ASON网络中一种基于折回点重路由的折回机制,当连接发生折回时,该机制通过折回点对连接进行重路由,从而省去了折回消息发送的过程。为了实现该机制,扩展了信令消息及处理流程。搭建了15个节点的试验平台,采用了RSVP-TE、OSPF-TE及LMP等协议来实现ASON网络的控制平面。试验数据显示该机制与传统的折回机制相比较,不但节省了信令通信网(SCN)的带宽,而且节省了连接的最终建立时间。