感知区分服务的MPLS流量工程技术研究

区分服务(Diffsevr)通过服务分级定义了流量的逐跳行为(PHB);流量工程(Traffic Engnineering)实现转发路径的优化。感知区分服务的MPLS流量工程(Diffsevr-aware MPLS Traffic Engnineering,简称DS-TE)将MPLS的区分服务与流量工程结合在一起,使其能够感知彼此的存在。DS-TE提出了基于类的资源分配思想,可以根据业务的类型,细粒度地建立交换路径,进一步保证了QoS。     

Diffserv-aware流量工程在MPLS中的应用

在多协议标签交换(MPLS)网络中,区分服务(Diffserv)对流量进行分类,为各种流量指定逐跳行为(PHB);流量工程(Traffic Engineering)实现转发路径的优化。感知区分服务的MPLS流量工程(DS-TE)将两者结合在一起,使其能够感知彼此的存在。DS-TE提出了基于类的资源分配思想,可以根据业务的类型,细粒度地建立交换路径,进一步保证了服务质量( QoS)。     

基于区分服务感知的MPLS网络流量分配方法

服务质量（Qos）和流量工程（TE）是在当今网络中提供实时应用业务的两种重要技术。多协议标记交换（MPLS）在IP网Qos提供和TE功能实现中起了关键作用。首先介绍了区分服务感知的流量工程（DS-TE），然后提出了一种基于DS-TE的网络流量分配新方法。给出了相关的数学模型，并进行了相应的仿真，仿真结果表明使用该方法实施DS-TE时，在满足不同业务的QoS同时能较好地均衡网络负荷。     

MPLS VPN差别化服务的实现技术模型及应用

为了满足互联网接入业务的服务质量需求,改变缺乏区分服务BGP/MPLS VPN网络的Qos的现状,提出了MPLS VPN网络的差别化服务应用模型,引入区分服务感知的流量工程(DS-TE)应用模型,通过MPLS Differ Serv模型在PE端的应用和DS-TE模型实现最小带宽的保证,从而实现高优先级业务服务质量的同时实现了优化网络资源的目的。     

基于资源能力需求计划的区分服务MPLS流量工程

本文对近期区分服务MPLS流量工程相关框架进行了研究，在此基础上提出一个新的框架结构。增加了新的模块包括资源能力计划、能力需求调度排期和路由路径管理模块，并提出平行路径资源调度新算法，模拟分析显示可以有效实现流量工程更高程度规划管理，增强了网络规划流量工程方面的性能。     

基于MPLS的流量工程仿真

多协议标签交换（MPLS）技术的成熟和扩展将推进基础网络的智能化和下一代光网络的实现。在对流量工程和MPLS体系结构分析的基础上,讨论了利用MPLS实现流量工程的优势。利用网络仿真器NS2设计了OSPF（开放最短路径优先）路由协议和MPLS流量工程的实例。通过对仿真结果的比较和分析,可以看出MPLS流量工程可以有效地实现网络负载均衡和恢复机制,提高网络服务质量。     

VOIP业务以及相关QoS性能的网络优化研究

简要介绍了VOIP传输的基本原理、传输机制，以及对影响VOIP业务QoS性能的3个主要因素（时延、抖动和丢包率）进行分析，提出了利用MPLS、diffserv—aware TE（流量工程）集成模型进行端到端QoS性能优化的方法和解决办法。MPLS、diffserv—aware TE能够感知CoS（服务等级），并提供根据CoS细粒度来预留带宽资源，在每个CoS级别提供MPLS容错的仉制，能够为VOIP提供低丢失、低延迟、低抖动以及确定的带宽服务，很好地满足服务质量的要求。     

基于MPLS的透明局域网服务

主要介绍了基于多协议标记交换（MPLS）技术的透明局域网服务（TLS）。详细分析了TLS业务流穿过MPLS网络时标记帧所发生的变化，并着重阐述了一种优化MPLS标记头的方法，使服务提供商能在基于MPLS的网络中扩展现有服务，从而提供具有QoS和流量工程的TLS服务。     

因特网上的MPLS流量工程

主要讨论因特网上多协议标记交换（MPLS）流量工程，首先简述了MPLS、约束路由技术以及增强链路状态内部网关协议，然后讨论了设计MPLS流量工程系统的主要问题，接着说明了配置MPLS流量工程系统的步骤，最后阐述了MPLS网络的QoS机制。     

计算技术与计算机及网络设备 程序设计语言

0627592基于UML的面向对象的系统建模〔刊,中〕/白运会//信息技术与信息化.—2006,(3).—146-148(D)0627593UML在基于工作流的项目管理流程中的应用〔刊,中〕/夏小娜//信息技术与信息化.—2006,(3).—133-135,138(D)0627594基于CBR和XML的知识管理系统架构研究〔刊,中〕/魏武华//计算机工程与设计.—2006,27(14).—2608-2610(L)0627595MPLS感知区分服务的流量工程的研究〔刊,中〕/王金辉//计算机工程与设计.—2006,27(14).—2516-2518(L)分析了MPLS区分服务和流量工程这两种技术;由于在一些应用情景下,需要使流量工程能够感知流量…     

MPLS VPN不同解决方案的比较分析

MPLS VPN是一种基于多协议标记交换(MPLS)技术的IP虚拟专用网络(VPN),是通过在网络路由和交换设备上应用MPLS技术,简化核心路由器的路由选择方式,并结合传统路由技术的标记交换来实现的.本文介绍了MPLS VPN的基本原理和发展现状,分析和比较了主要的2层(L2)和3层(L3)MPLS VPN技术.     

一种基于MPLS网络的优化模型算法

M PLS已经成为NGN发展的重要技术,为了通过有效流量工程来达到提供Q oS和优化资源分配的目的,可以用混合整数数学方程(优化)技术来模拟路由问题,可以使构建、应用和维护网络成本最低,因此本文提出了一种基于M PLS网络链路计算的优化模型算法,使其应用于M PLS网络规划,根据容量和网络结构限制以及标签交换路径生存能力来安排路由,并结合两个网络实例得到证实。     

MPLS技术及其在流量工程中的应用

MPLS（多协议标签交换）具有很多适合于缓解拥塞和平衡负载的特点，它的提出和发展为流量工程的实施开辟了一条崭的道路。本主要针对MPLS和流量工程相关的问题进行探讨，分析了如何利用MPLS来实施流量工程。     

Creating multipoint-to-point LSPs for traffic engineering

Traffic engineering enhances an ISP's capability to manage and utilize its resources effectively. MPLS has emerged as an efficient packet forwarding tool that gives a significant boost to the traffic engineering capabilities of an ISP. A fundamental problem in MPLS is to reduce label space usage by label switched paths while meeting the requirements of the flows traversing the network. Using multipoint-to-point LSP trees has been proposed as one of the techniques to reduce label space usage. We look at the problem of creating multipoint-to-point LSPs given a set of precomputed point-to-point LSPs. We propose a heuristic for multipoint-to-point LSP creation and show its effectiveness.     

Efficient Distributed Bandwidth Management for MPLS Fast Reroute

As service providers move more applications to their IP/MPLS (multiple protocol label switching ) backbone networks, rapid restoration upon failure becomes more and more crucial. Recently MPLS fast reroute has attracted lots of attention as it was designed to meet the needs of real-time applications, such as voice over IP. MPLS fast reroute achieves rapid restoration by computing and signaling backup label switched path (LSP) tunnels in advance and re-directing traffic as close to failure point as possible. To provide a guarantee of bandwidth protection, extra bandwidth has to be reserved on backup paths. Using path merging technique as described in IETF RFC 4090 only, the network is able to share some bandwidth on common links among backup paths of the same service LSP, i.e., so-called intra-sharing. But no solution is provided on how to share bandwidth among backup paths of different service LSPs, i.e., so-called inter-sharing. In this paper, we provide an efficient distributed bandwidth management solution. This solution allows bandwidth sharing among backup paths of the same and different service LSPs, i.e., both intra-sharing and inter-sharing, with a guarantee of bandwidth protection for any single node/link failure. We also propose an efficient algorithm for backup path selection with the associated signaling extensions for additional information distribution and collection. To evaluate our schemes, we compare them via simulation with the basic MPLS fast reroute proposal, IETF RFC 4090, on two networks. Our simulation results show that using our bandwidth management scheme can significantly reduce restoration overbuild from about 250% to about 100%, and our optimized backup path selection can further reduce restoration overbuild to about 60%.     

RATES: a server for MPLS traffic engineering

It has been suggested that one of the most significant reasons for multiprotocol label switching (MPLS) network deployment is network traffic engineering. The goal of traffic engineering is to make the best use of the network infrastructure, and this is facilitates by the explicit routing feature of MPLS, which allows many of the shortcomings associated with current IP routing schemes to be addressed. This article describes a software system called Routing and Traffic Engineering Server (RATES) developed for MPLS traffic engineering. It also describes some new routing ideas incorporated in RATES for MPLS explicit path selection. The RATES implementation consists of a policy and flow database, a browser-based interface for policy definition and entering resource provisioning requests, and a Common Open Policy Service protocol server-client implementation for communicating paths and resource information to edge routers. RATES also uses the OSPF topology database for dynamically obtaining link state information. RATES can set up bandwidth-guaranteed label-switched (LSPs) between specified ingress-egress pairs. The path selection for LSPs is on a new minimum-interference routing algorithm aimed at making the best use of network infrastructure in an online environment where LSP requests arrive one by one with no a priori information about future requests. Although developed for an MPLS application, the RATES implementation has many similarities in components to an intradomain differentiated services bandwidth broker     

MPLS网络主动式流量和拥塞控制机制及性能分析

MPLS是具有大带宽一时延迟的网络,用传统的TCP解决MPLS拥塞问题显得十分困难,该文结合MPLS的网络特点,提出了一种适合MPLS网络的主动式流量和拥塞控制机制,在网络边缘节点引入拥塞反馈处理,对实验模型进行了性能仿真分析,实验证明,与传统的TCP协议相比,该机制将流量和拥塞控制从用户端点扩展到MPLS边缘路由器,能够更及时地检测和控制网络拥塞,缩短了控制时延,可以进行较精确的流量调节,实现了提高吞吐量和改善缓冲区利用率的目的。     

基于人工蜘蛛的MPLS路由及重路由模型

该文在对MPLS工作原理深入了解的基础上,提出了一种新的路由模型S-DQRA,希望在为业务建立LSP之初不仅考虑业务的实际需求,而且保证网络资源的合理利用。在此基础上,为了保证可靠的服务,又提出了一种新的重路由模型S-DQRRA。在失效发生时迅速启动,将工作路径上的流量切换到备份路径上。最后,用NS对这两种模型进行了仿真实验,并分别与其经典的模型进行了比较,实验结果表明该文提出的路由及重路由模型均具备良好的工作性能。     

MPLS: the magic behind the myths [multiprotocol label switching]

This article reviews the key differences between traditional IP routing and the emerging multiprotocol label switching (MPLS) approach, and identifies where MPLS adds value to IP networking. In various corners of the industry MPLS has been held up as the solution to IP QoS, gigabit forwarding, network scaling, and traffic engineering. Each of these expectations is critically considered in the light of developments in conventional gigabit IP routers. It is shown that MPLS adds the ability to forward packets over arbitrary non-shortest paths, and emulate high-speed “tunnels” between IP-only domains-capabilities critical to service providers who need to better manage resources around their backbones, or who are planning IP VPN services. However, it is also argued that the technology required to support IP QoS and gigabit forwarding is not unique to MPLS. A network of gigabit IP routers or switches may be entirely sufficient for QoS and performance if traffic engineering is not a requirement     

Traffic Measurement for Traffic Engineering in IP/MPLS Based Telecom Core Networks

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