MPLS-TP Based Research On Key Problems Of Technologies In Packet Transport Networks

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.