Research Of Pce-Based Routing Technology And Resources Assignment In Intelligent Optical Networs

The demand of business promots the progress of technology. With the rapid development of internet, more and more data applications have appeared, at the same time, the requirements of the underlying reliable transport are also increasing. Optical transport network as a key part of telecommunications network, bearing the backbone network optical signal long distances and high reliability transmission mission. With the people’s requirements increasingly for differential service, high reliability and real-time, build large-scale and scalable multi-layer multi-domain intelligent optical networks is the trend of development in the future. However, in multi-domain networks, each domain only knows of the local domain topology and resource information, can not know of other domains’related information due to the privacy and security restrictions, so there are many limitations in computation and construction the cross-domain path. PCE[1], proposed by IETF in2006, is a separate path computation entity, can compute a completed end-to-end cross-domain path under consideration many constraints. The dissertation content mainly from the project works and research results, mainly contributions are listed as follow:Firstly, in-depth study of PCE and the relevant protocol standards, design and implementation of PCEP communication protocol and key external interfaces. The works mainly including design PCEP protocol three layer functional architecture, the implementation of interfaces, which are parts of PCEP protocol library, the implementation objects and messages defined in RFC5440. In addition, to achieve the optimal end-to-end LSP in computation cross-domain path in our experimental platform, BRPC [14]algorithm described in RFC5441has been implemented by code. Secondly, in-depth study of PCE-based routing computation technology, including the cross-domain routing computation technology in multi-domain optical network and cross-layer routing computation technology in multi-layer network. All technologies have been demonstrated by different detailed examples. In addition, for the problems of resource assignment in optical network, mainly is wavelength assignment problem, we summarized existing wavelength assignment methods. Besides, in terms of wavelength assignment flexibility and network scalability, we proposed extend OPEN object and RP object defined in PCEP protocol to support the customer choosing the wavelength allocation policy freely.Thirdly, we proposed a PCE-based cross-domain path protection strategy by bidirectional recursion computing cross-domain link-disjoint working and protection paths to satisfy the requirement of high reliability and real-time. The basic idea of this method is forward recursion computing work path and backward recursion computing protection path. Suurballe[51] algorithm is used in every domain to ensure both work path and protection path are disjoint.Finally, OpenFlow[60] as an implementation technology of SDN, is receiving more and more attention and participation. Based on the in-depth study of OpenFlow technology, we proposed a new network architecture by means of controllers cooperating to complete the cross-domain path computation and the establishment in OpenFlow/PCE network. The integrated controller structure, protocol extensions and the procedure of lightpath establishing are introduced in detail. Based on the proposed architecture, we have performed a simulation. The simulation results show that when the network scale is larger, the proposed architecture in terms of connection setup time and blocking probability could get the best performance. The multi-domain multi-controller is more applicable to large-scale and scalable optical networks.