分组传送网技术与测试

分组传送网是网络融合的产物,在电信行业全业务运营背景下,这一技术代表了传送承栽网络的IP化发展趋势。文章就分组传送网的关键技术特征、实现技术原理进行了概括的分析,详细介绍了基于T—MPLS/MPLS-TP的分组传送网设备组网性能的测试方法和面临的问题。     

T—MPLS层网络中网络互通技术的探讨

根据目前的发展趋势，基于T—MPLS（传送-多协议标签交换）技术的下一代分组传送技术将逐渐成为一种新的传送体制。介绍了T-MPLS技术的研究现状，重点从网络的互联互通角度分析了基于分组交换传送网的T-MPLS网络与传统SDH网络的不同，提出了T—MPLS网络的互联互通结构，并对如何开展T-MPLS互联互通的下一步研究工作进行了探讨。     

传送网络转型:分组传送网PTN

业务的分组化导致传送网络的分组化,分组传送网保持传统传送网的优点,同时增加适应分组业务统计复用的特性。分组传送网的关键技术是MPLS-TP技术,分组传送网应用在城域接入、汇聚网中,比如无线承载网等、核心网lP流量旁路。     

市场

华为路由器通过EANTC测试 本刊讯10月19日,华为宣布其路由器通过全球权威测试机构EANTC组织的IP／MPLS和MPLS-TP多厂商互通测试,成为业界首家支持单系列产品在IP／MPLS和MPLS-TP两个领域实现成功互通的设备商。本次EANTC互联互通测试基于MEF、ITU-T、IEEE和IETF标准,聚焦移动承载、统一传送、运维管理和网络保护。华为系列路由器产品CX600和PTN参与了本次测试,     

PTN技术发展现状和应用探讨

本文对分组传送网（PTN）和MPLS-TP技术的发展情况进行了介绍,包括MPLS—TP的标准化情况,PTN设备发展和测试情况．对IEEE 1588V2和同步以太网的支持,对LTE的承载方式探讨,以及PTN网络中的QoS的考虑等。     

盛科推出MPLS-TP OAM硬件方案

盛科网络（苏州）有限公司日前宣布推出了业界领先的基于硬件的MPLS-TPOAM方案,同时支持基于BFD扩展和基于GACH封装Y.1731（BHH草案）的MPLS-TPOAM协议。该方案的推出使电信设备制造商特别是传输设备制造商能够灵活地部署基于MPLS-TP的传输设备并与IP／MPLS核心网互通．保证承载网向分组传送网PTN）平滑升级。     

分组传送网(PTN)的生命力探讨

随着科技的不断发展,推动了我国分组传送网技术的发展。本文首先对分组传送网(PTN)进行了概述,并从数据转发机制、网络扩展性、多业务承载能力、QoS机制以及网络保护方面的差异探讨了PBB-TE和MPLS-TP两种分组传送网主流技术的特征和差异,以期为我国分组传送网研究提供一些参考。     

PTN技术发展及在IP RAN承载中应用的探讨

1 引言 为了应对全业务挑战,主要运营商的网络和业务都开始向分组化演进,从而提出了PTN的概念。下一代网络中的传送网将融合现有的光传送网和以太网／IP／MPLS网络的特点,实现对分组业务的高性能传送。目前主流的分组传送网技术有两种,分别是T—MPLS／MPLS—TP和PBT／PBB-TE。     

分组传送网（PTN）技术及发展

 本文通过市场需求和网络融合发展趋势,分析了分组传送网产生和发展的原因。阐释了分组传送网的关键技术,包括PTN架构、业务、OAM、QoS、生存性技术、同步技术、控制技术、交换技术等。描述了分组传送设备的类型和功能特性及在网络中的应用。文中还对分组传送网有关标准尤其是MPLS-TP相关标准的发展情况进行了介绍。通过对需求、技术、应用、标准几个方面情况,可以理解分组传送网的发展趋势。     

分组传送网技术发展中的若干问题

文章对分组传送网（PTN）/传送多协议标记交换（MPLS-TP）技术和标准发展过程中的关键问题,包括端到端的服务质量（QoS）实现机制、网络分层结构、三层（L3）功能的引入和数据平面环回功能等进行了探讨,并基于PTN网络建设维护和开展业务的需求提出了自己的观点。通过对PTN网络中的基于MPLS的流量工程和区分服务两种机制的分析,文章提出了一种面向业务的端到端的QoS保障机制。基于已有的MPLS-TP标准和草案明确的PTN的分层结构,文章提出了在PTN中引入L3功能的方式。文章还提出了数据平面环回功能的需求。     

MPLS-TP的业务适配与标签转发机制

传送网承载的业务从以时分复用（TDM）为主向以IP为主转变,需要一种能够有效传送分组业务的新技术。传送多协议标记交换（MPLS-TP）作为一种面向连接的分组传送技术,具有高效的多业务适配能力和灵活的标签转发机制。从MPLS-TP技术特性入手,文章基于MPLS-TP标准化的最新进展,重点讨论了与MPLS-TP有关的数据转发平面,以及业务适配和标签转发机制等关键技术,包括信号适配、分组交换与转发和双标签信令传送实现等内容,说明了基于双标签传送模式的虚拟专用网的业务实现方法,并总结了MPLS-TP的应用情况。     

Service Adaptation and Label Forwarding Mechanism for MPLS-TP

Most services borne by transport networks have been transitioned away from Time Division Multiplexing (TDM) towards IP-based. New technology is therefore required to effectively transport packet services. Multiprotocol Label Switching Transport Profile (MPLS-TP) is such a technology which is connection-oriented, capable of multiservice adaptation, and has a flexible label forwarding mechanism.This paper analyzes the characteristics of MPLS-TP, and introduces its latest standardization development. Key issues including data forwarding plane, service adaptation, and label forwarding mechanism are discussed, as well as service implementation of Virtual Private Network (VPN) based on dual-label transport. MPLS-TP applications are summarized in conclusion.     

Transport architecture evolution in UMTS/IMT‐2000 cellular networks

Mobile evolution from the second generation (2G) to the third generation (3G) raises several important questions for operators and manufacturers. How to ensure that the old and current investments can still be utilized in the future? What is the optimum architecture? ATM or IP? Voice or data? There is no single correct answer to these questions, as it all depends on individual cases. In this paper, we discuss the transport architecture evolution for the universal mobile telecommunications system (UMTS)/international mobile telecommunications—year 2000 (IMT‐2000), or 3G cellular networks and interworking aspects between 2G and 3G cellular networks. The interfaces between access nodes in a cellular network and the changes incorporated to support packet data services are described. Emerging services such as mobile data, virtual private networks (VPN) and location aware networking are described. Role of ATM and IP in this new transport architecture is presented. Control and data plane interworking issues between different transport technologies are described. The new ATM standard, ATM adaptation layer type 2 (AAL2) and its applicability for transporting compressed speech in an ATM based cellular network is described. A similar approach in IP, multiplexing in real‐time transport protocol (RTP) payload to transport compressed speech on selective interfaces of 3G network, is introduced. Transport network architecture evolution within four different scenarios is evaluated. Special interest is focused on the protocol stacks and flexible layered solutions that allow smooth migration from one transport technology to another. Copyright © 2000 John Wiley & Sons, Ltd.     

Supplementary services in the H.323 IP telephony network

Traditionally, different networks were developed to handle voice, data, and video. The circuit-switched telephone network carried voice and the packet network carried data. Due to different deployment of these networks, different services were developed, such as voice mail in the telephone network and electronic mail on the Internet. With the revolution of multimedia in the computer industry, voice, video, and data are now being carried on both networks. Supplementary services, such as transfer and forwarding (which were originally developed for private telephone networks and later migrated to public telephone networks) are now being developed for packet networks. The standards for packet networks are being defined in the H.323-based series of ITU-T recommendations. This article provides the H.323 architecture for supplementary services, the differences in deployment of these services between the circuit-switched and packet-switched networks, and interworking of these services across hybrid networks     

OTN+MPLS-TP技术

通过与SDH技术对比,概述了光传送网(OTN)的优势所在.因此,SDH向OTN演进是光网络发展的一种必然趋势.介绍了OTN技术现状和MPLS-TP技术特点,指出"OTN+MPLS-TP"技术是光网络下一步发展的方向.     

MPLS-TP的OAM机制基于FPGA的实现

操作、管理、维护（OAM）机制是加强对分组传送网络的管理和控制关键。继传输多协议标签（T-MPLS）技术以后,MPLS-TP吸收了三层IP、二层PWE3和一层TDM/OTN技术的优点,将OAM技术进行了继承和发展。作为分组交换网络（PTN）的主流技术,MPLS-TP必须拥有强大的OAM技术才能更加具备市场竞争力。主要对其硬件实现的方法进行了研究,首先详述了MPLS-TP网络的OAM网络模型及主要功能。重点对OAM功能硬件实现方式进行了讨论,提出了实现方案,详述了各个功能模块的逻辑处理过程及具体电路实现。方案还需要进一步的进行系统级的验证,将在今后的研究中会逐步完成。     

Architecture for interworking data over PCS

This article presents a new approach for wireless service providers to offer data services by taking advantage of the existing infrastructure for voice services and interworking with existing wireline-based data services. The article presents a framework: for interworking between any wireless radio system and any data application on the wireline network. The interworking is provided by a common interworking function that uses a generic interworking control protocol (ICP). Any radio system capable of using the ISDN-based C-interface and implementing ICP can take advantage of the proposed approach. ICP is a generic protocol and can be implemented using different networks. The article considers an ISDN network for the lower-layer transport of ICP. Though the article focuses on interworking with the PSTN and the Internet, the architecture also allows access to other data networks     

UMTS-WLAN异构网络互联的方案研究

通用移动通信系统(UMTS)为移动数据用户提供了较广阔的覆盖范围,而无线局域网(WLAN)能在局部热点地区提供较高的接入带宽.两种网络的显著优势能够相互结合,为处于异构网络覆盖地区的用户提供网间无缝连接.本文总结了目前UMTS-WLAN互联的三种实施方案:移动IP、互联网关和仿真器.在分别介绍三种方案的体系架构、互联机制和切换流程后从互联层次、信令和数据流向、对现有网络的改造、安全认证机制及用户管理方式等不同层面分析三种方案的特点.     

浅谈IMS和PSTN/CS网络的互通

IP多媒体子系统自从3GPP UMTS Release5后已经被加入到通用移动通信系统(UMTS)的核心网络中.现在,UMTS网络主要包含以下3个域:电路交换(CS)、分组交换(PS)和IP多媒体子系统(IMS).IMS需要同原有相对陈旧的网络电路交换(CS)网络及公用电话交换网(PSTN).本文主要针对IMS同PSTN/CS网络的互通进行了概述.     

下一代网络(NGN)互通框架模型的探讨

主要从网络分层的角度探讨了NGN和各种网络之间互通的实现方法。首先给出了NGN的互通功能模型，然后重点探讨了NGN与PSTN、H．323 VoIP网络以及IN网络的互通模型，分析了NGN和上述各种网络在传输层、交抛佳路层、应用层和网络资源4个层面上实现互通的要求和方法。