MPLS及其在IP网络中的应用

多协议标记交换(MPLS)技术是当今网络界研究及讨论的热门话题,它不但能提高传统路由器的分组转发性能,还能应用于流量工程、提供服务质量(QoS)保证以及虚拟网构建等方面。文章重点介绍了MPLS的原理和关键机制,分析了MPLS在IP网络中可能有的应用,同时指出了MPLS所存在的问题。     

IGP/MPLS混合的IP网络不确定流量规划方法

随着IP网络的迅速发展,网络的业务量越来越呈不确定性和不可预测性。针对此问题,提出了以软管模型为基础的不确定业务量模型下的IGP/MPLS混合IP流量规划问题的混合整数规划(MIP)模型,并将该模型分解成权重设计子问题和流量分配子问题进行求解。实验结果表明,该方法能在标签交换路径(LSP)较少的情况下达到较理想的优化效果。     

基于OPNET的MPLS网络流量工程仿真分析

MPLS（Multi-Protocol Label Switching）即多协议标签交换,作为下一代网络中的一项交换技术,正受到越来越多的人的关注。该论文使用网络仿真工具OPNET Modeler,对MPLS网络的流量工程（Traffic Engineer）进行了仿真分析。从仿真结果中可以看到MPLS技术在网络的流量管理、负载均衡等方面都有着很大的效率,比“尽力而为”型的传统IP网络在使用网络资源、处理网络新业务上表现出了更大的优势。     

MPLS网络工程流量分析

多协议标签交换MPLS（Multi-Protocol Label Switching）是一种高效的数据包交换技术,提供了标记、路由、转发等能力．论文使用OPNET软件,对MPLSTE技术在网络流量管理与负载均衡等方面进行仿真对比,与传统的IP网络相比具有更优异的表现。     

MPLS技术及其发展趋势

多协议标签交换使用定长的标签来引导数据高速传输和交换。MPLS,实现了增强的流量工程和负载均衡,为服务供应商和企业改善整体网络管理、更好地利用可用带宽提供了技术支持。MPLS技术为传输网和光网络、支持移动IP、以及在无线移动通信网的发展中提供了重要解决方案     

Fast setup of end-to-end paths for bandwidth constrained applications in an IP/MPLS–ATM integrated environment

Transport networks are currently being moved towards a model of high performance Internet Protocol/Multiprotocol Label Switching (IP/MPLS) routers interconnected through intelligent core networks. Currently, Asynchronous Transfer Mode (ATM) technology has been widely deployed in several network backbones along with the Private Network-to-Network Interface (PNNI) protocols as the control plane. In order to cope with the increasing Internet traffic demands in the current context, fast setup of end-to-end paths with the required Quality of Service (QoS) is necessary.This paper analyzes the case of two IP/MPLS networks interconnected through an ATM core network, assuming MPLS as the mechanism to provide Traffic Engineering in the IP networks, and a PNNI-based control plane in the core network. This paper aims to define a mechanism needed to set up a fast end-to-end QoS Label Switched Path (LSP) between two Label Switched Routers (LSRs) belonging to different IP/MPLS domains. First, the fast end-to-end setup is achieved by modifying the network backbone control plane. Second, two different aggregation schemes are proposed to summarize the QoS network state information to be transported through the ATM core network. Therefore, both the efficient aggregation schemes and the fast mechanism allow source routing to set up a path faster than the existing methods and to reduce the blocking probability using a summary of the available resource information.     

The IETF Multiprotocol Label Switching Standard: The MPLS Transport Profile Case

Multiprocol Label Switching (MPLS) is a technology for traffic engineering for and the optimization of IP networks. It's also an enabling technology for building applications on top of IP networks. The IETF has standardized the MPLS protocol suite, as well as technologies — such as virtual private networks and pseudowires — that build on it. MPLS is a mature technology and is used extensively by all the major network operators. The IETF has also standardized a technology — Generalized MPLS — that extends the MPLS control plane for use with other data plane technologies.     

Policy-Based Grooming in Optical Networks

This work presents a discussion about policies and architecture to aggregate Internet Protocol/Multiprotocol Label Switching (IP/MPLS) traffics within lightpaths. The scenario is that of IP/MPLS client networks over an optical network. It is well known that aggregating lower traffic flows (e.g., packet-based LSPs—Label Switched Path) within higher traffic flows (e.g., lambda-based LSPs) is considered an effective way to maximize the use of the optical network resources. In this work, the policies are divided into two groups. The first one, which solely considers the class of the flow (High Priority—HP or Low Priority—LP), consists of simple policies meant to aggregate packet-based LSPs within lightpaths. In this group, the policies we have defined intend to reduce the optical network overhead to remove and reroute LP LSPs. The second group presents more sophisticated policies taking into account the possibility of having to deal with further transport faults. In this case, the grooming is better planned and the defined policies tend to reduce the negative impact when a failure is detected in the optical transport network. Our approach has been implemented to validate the policies and the results for each group are showed and discussed.     

移动IP分布式路由优化研究

IETF提出的移动IP协议对微移动的支持不够,而分布式路由方案能较好地解决该问题。该文在一种分布式移动IP方案的基础上进行了改进：将转向代理的缓存修改为循环列表,减少移动节点接收的乱序分组;当切换转向代理时,移动节点向前一个转向代理发送绑定更新消息,减少转向代理切换时的分组丢失;在转向代理处引入Snoop机制,减少通信对端重传分组数。利用NS2软件对两种方案进行了仿真。仿真结果表明,改进的方案能够明显地减少重传分组和乱序分组,进一步减少远程信令流量和数据流量,提高网络资源的利用率,有效地改善移动IP的性能。     

IP网络中实时连续媒体传输策略

文章讨论了在IP网络上实现实时连续媒体传输的多种方法,给出了基于MPLS、RSVP和会话层的实时连续媒体传输策略,并对它们的QoS和管理复杂性进行了分析和比较。提出在IP网络中真正实现实时连续媒体传输的途径是对网络资源特别是主干网络资源进行统一调配和管理。     

广电网多业务宽带传输技术研究

文中介绍了采用ＩＰ与ＡＴＭ技术实现广电网多业务宽带传输,建立一个以宽带ＡＴＭ技术为基础,同时供多层次服务的支持端对端多媒体应用的信息服务网络,以及在建网过程中所要考虑的重要因素。     

MPLS VPN技术在党校系统虚拟网络中的应用研究

基于多协议标签交换（MPLS）的IP虚拟专用网（IP／VPN）是目前VPN发展的主流方向。本文简要介绍了MPLS VPN技术相关特点和工作原理．重点阐述了利用MPLSVPN技术构建党校系统虚拟专网的三种具体接入方法。     

Survivable ATM mesh networks: Techniques and performance evaluation

The Capacity and Flow Assignment problem in self-healing ATM networks is an interesting one from a Generalized Multi-Protocol Label Switching (GMPLS) prospective since IP and ATM protocols are destined to co-exist together in this unified platform. This paper continues the investigation of the path-based design approach of the network survivability problem in existing ATM mesh networks. Our contribution consists in quantifying (1) the effects the selection of candidate paths per node pair has on the restoration ratio, (2) the effect of restoration schemes on the restoration ratio, (3) the effect of failure scenarios on the restoration ratio, and finally (4) the effect of network connectivity on the restoration ratio. Numerical results are presented under representative network topologies, various traffic demands and spare capacity distribution schemes. They provide additional guidelines for the design of survivable ATM mesh-type networks, from a network reliability viewpoint.     

多协议标记交换(MPLS)技术研究

为了解决目前以Internet为主的IP主干网络所面临的问题,IETF提出了多协议标签交换(MPLS)。文章对MPLS的基本概念及其工作原理进行了分析,并简要给出了MPLS的几个应用。     

Design and Analysis of a Backbone Architecture with TDMA Mechanism for IP Optical Networking

This paper presents a new technique for constructing IP over photonic systems. The use of lable switching is assumed in the IP routers, while a new routing architecture is introduced to transport IP packets across an optical backbone network. The architecture is based on a two-level TDMA structure with wavelength division multiplexing (WDM). Many IP-based network applications such as high-resolution image, distributed database, and real-time video/audio service generally require high-speed transmissions in WAN/LAN. The network traffic in these applications usually exhibits traffic locality. As a result, traditional TDMA is not efficient for such traffic. Consequently, based on the traffic parameters such as locality and loading, an architecture named a PG (Partition-Group) Network is proposed. Furthermore, the interleaved control slot (ICS) with cross-group section (CGS) or non-cross-group section (NCGS) for reducing collisions is also presented. The slot reuse can be easily achieved by using the ICS scheme, and the slot utilization of the network can be improved within the high traffic locality.     

多协议标签交换（MPLS）技术研究

ＡＴＭ和ＩＰ是目前应用非常广泛的两种组网技术）,二者各有自己的优点和缺点。随着用户对综合业务网络需求的不断增强,ＡＴＭ和ＩＰ的融合成为未来网络技术发展的趋势。ＡＴＭ和ＩＰ的融合有多种方式,ＭＰＬＳ是其中被公认为最有前途的一种方案。本文对ＭＰＬＳ的基本概念,工作原理,交换过程等作了一个系统的介绍。     

An admission control scheme for end-to-end statistical QoS provision in IP networks

This paper presents a distributed and scalable admission control scheme to provide end-to-end statistical QoS guarantees in IP network.The basic idea of the scheme is that the ingress routers make admission control decisions according to the network status information obtained by sending probing packets along the selected routing path.Each router passively monitors the arriving traffic and marks the probing packets with its network status.The performance of the presented scheme is evaluated with a variety of traffic models,QoS metrics and network topologies,The simulation results show that the proposed scheme can accurately control the admissible region and effectively improve the utilization of network resource.     

Mobility label based network: Hierarchical mobility management and packet forwarding architecture

Scalability of the network layer mobility management solution is one of the most important requirements for the mobility control plane. Mobility Label Based Network (MLBN) is a new approach to the network layer mobility management problem that relies solely on MPLS to provide both macro- and micro-mobility for IPv4 and IPv6 mobile hosts and routers. This new approach does not rely on the existing IP mobility management protocols such as Mobile IP and is based on the combination of Multi-Protocol BGP (MP-BGP) and MPLS. In the context of the MLBN the scalable control plane should be capable of efficient Mobility Label distribution while allowing the MPLS-based forwarding plane to deliver mobile traffic in an optimal manner. This paper presents a hierarchical mobility management system capable of both macro- and micro-mobility support without the use of Mobile IP and its derivatives and allows scalable Mobility Label distribution and MPLS label stack based packet forwarding in support of optimal traffic delivery between the communicating mobile users.     

MPLS实现流量工程及服务质量的技术分析

本文阐述了多协议标签交换技术（MPLS）的基本原理,并重点对MPLS如何实现IP网络的流量工程和支持服务质量及服务等级保证等进行了详尽的介绍,最后展望了MPLS技术的发展前景。