节点文献
基于MPLS-TP的分组传送网络关键技术研究
MPLS-TP Based Research on Key Problems of Technologies in Packet Transport Networks
【作者】 张志辉;
【导师】 顾畹仪;
【作者基本信息】 北京邮电大学 , 电磁场与微波技术, 2011, 博士
【摘要】 随着3G的大规模商用和VoIP、IPTV等网络应用的普及,为了适应全网运营以及IP化发展需要,分组传送网(PTN)技术得以飞速发展。其中PBB-TE和T-MPLS是目前业界呼声最高的两种技术。凭借多业务的接入能力、端到端的传送保证、良好的OAM和QoS特性,T-MPLS技术成为PTN演进方向的不二选择,其发展也日趋成熟完善。不久前,ITU-T和IETF更是成立了联合工作组进一步开展相关工作,并将其定义为MPLS-TP。本论文在国家863项目“基于T-MPLS的电信级分组传送网络”和863重点项目“基于分组的光传送关键技术与实验系统”的支持下,将重点研究MPLS-TP技术在分组传送网络中的应用,通过搭建综合试验平台,研究包括MPLS-TP节点分组交换、转发单元、信令协议、路由协议、管理模型和网管系统、OAM,以及路由算法和生存性策略以及利用MPLS-TP中双标签机制形成的分组管道实现对多种业务的统一承载和传送等内容。PTN和光传送网(OTN)分别作为光传送网在接入层面和核心层而的两大发展方向,可以通过灵活的适配、调度结合起来。然而在汇聚层而,PTN和OTN相融合的研究工作还有待深入。本论文将在MPLS-TP技术体系研究的基础上,利用已有成果及试验平台系统,针对MPLS-TP业务不断增长的潜在需求和OTN承载业务效率不足的现实问题,立足于对承载MPLS-TP业务的OTN进行节点功能模型和体系结构的研究,最终实现融合两种技术优势的MPLS-TP业务承载,并充分提升网络综合能力。本论文从上述两个方面入手,对分组传送网络的功能特性展开了深入研究,并围绕各项关键技术取得了若干具有创新性的研究成果,主要的工作和创新点包括以下几个方面:第一,从MPLS-TP传送技术原理入手,对分层结构、层级接口、业务适配、标签转发机制等方面技术内容进行深入研究。根据不同业务接入的实际需求,分析不同业务的特性并提出相应的自适应队列分配策略。通过差异化处理,在包含多种业务统一接入的分组传送网中实现了端到端的高效传输保障。最后提出了一种MPLS-TP光传送网络多业务节点的实现方法。第二,针对MPLS-TP over OTN多层网络的融合问题,基于两种原有网络技术进行研究,然后分析现有多层网络中对不同业务传送存在的问题,并提出区分优先级的业务传送方案,以完成分组传送网对全业务统一传送的高保障要求;在此基础上,提出OTN节点MPLS-TP业务通道资源分配算法,分析不同承载方式对传输性能的影响。第三,在分析分组传送网生存性的基础上,提出一种多域故障并发下的生存性技术。该技术定义并划分整个分组传送网络,在每个域内实现快速的路由保护算法策略。该技术通过扩展协议信令及关键节点处理,利用不同域的分割隔离,达到提高响应效率、实现资源优化的目的。第四,在上述研究内容的基础上,根据MPLS-TP相关标准及技术原理设计了基于MPLS-TP的分组传送网实验网架构,提出MPLS-TP节点功能模型及多业务传送的封装/解封装解决方案,并在此基础上作为主要成员参与完成硬件传送平台的设计与实现,为分组传送网中各种功能及优化算法的研究提供分析验证手段。
【Abstract】 With 3G large-scale commercialization and packet network applications (such as VoIP, IPTV) popularization, in order to meet the development needs of IP-based and the entire network operations, Packet Transport Network (PTN) is developing rapidly. There are two main PTN technologies:PBT and T-MPLS. Due to multi-granularity access capability, good OAM and QoS features, T-MPLS technology is considered as the direction of PTN, and its standard also has been improved greatly. At present, the major domestic equipment manufacturers such as Huawei, ZTE and Fiberhome adopt T-MPLS technology as PTN devices. What’s more, ITU-T and IETF have set up a joint working group to develop relevant work further, and defined it as MPLS-TP.With the support of the High-Tech Research and Development Program of China, the MPLS-TP applications in packet transport networks are investigated in depth in this paper. Through building the testing platform, we will study MPLS-TP key technologies including packet switching, transmitting mechanism, signaling protocol, routing scheme, OAM, survivability scheme, management model etc, and implement the unique bearing and transporting in dual-label in multiservice.PTN and Optical Transport Network (OTN) are considered respectively as the directions of access layer and core layer in Metro networks, through the flexible configuration and efficient scheduling, they can be deployed at different networks layers. However, in convergence layer, the integration of PTN and OTN needs further research. Based on the potential demand of MPLS-TP and solving the reality problem of low bearing efficiency in packet services, we proposed the study of MPLS-TP over OTN node functional model and architecture research. The main contents include searching the best PTN transport scheme by comparing different carrying methods in OTN node; studying the survivability in MPLS-TP over OTN which focuses on protection routing algorithm under concurrent multi-domain fault in rings. From the above two aspects, this paper studied on the functional characteristics of packet transport networks in depth, and harvested innovative research results, the main work and innovative contributions are listed as follow.Firstly, from the principle of MPLS-TP transport technology, the research contents include the structure of hierarchies, layer interface, service adaption, the mechanism of label forwarding and so on. According to the actual needs of different service, we analyzed the characteristics of different business and proposed a collision-aware queue assigning scheme. By processing differently, we achieved an efficient end to end transport gurantee in multiservices in PTN. And then, we analyzed and designed of a FPGA-based implementations for TDM, and proposed a node implementation for multiservice in MPLS-TP.Secondly, for the problems of MPLS-TP over OTN in multi-layer networks, the integration between MPLS-TP and OTN is studied. By analyzing of problems of multiservice accessing in existing multi-layer networks, we implemented a prioritized service transport scheme to meet requirements of the unique transport for full service. Based on this, a service path resource assigning algorithm in OTN node is proposed to analyze the effect of the transmission performance in different service bearing methods.Thirdly, based on the study of survivability technologies in PTN, we designed a survivability scheme in a multipledomain fault which defines and divides the whole network into some areas running its own routing protection algorithm quickly and respectively. Through expanding the related protocols and key node operation, the scheme can isolate different faults in different areas to the aim of promoting efficiency and optimizing resource distribution.Finally, based on the above research, and according to the related standards and theory, network architecture of MPLS-TP and the functional model of nodes are designed, including transport unit, control unit and management unit. Adaptation and carrier of multiservice in the platform are researched. As the main researcher, I took in charge of designing and implementing the hardware platform which provides the means to analyze and verify all kinds of improved functions and optimized schemes.
【Key words】 Packet Transport Network (PTN); dual-label; survivability; Optical Transport Network (OTN); routing protection;