Research On Virtual Optical Net- Work Mapping Based On Flexible Spectrum Optical Network

From the 1970s, now, with the rapid development of technology and services, optical network is constantly breaking through and innovating.Especially in recent years, due to the explosive emergence of new technologies such as cloud computing, high-definition video broadcast,virtual reality and internet of things , Various requirements for the optical network transmission in the new business are also increasingly diverse,traditional optical network is also caught in the deep contradictions between the emerging new business and rigid network structure. The virtualization technology of optical network can effectively solve the problem of insufficient flexibility of optical network architecture, and better meet the flexible, reliable, scalable service needs. So the optical network virtualization is the trend of transmission networks in the future,and one of the key technologies in the age. Because of the ineficient use of spectrum with a fixed pattern in the traditional WDM optical network,this paper focuses on the research of the virtualization technology based on the flexible spectrum optical network.Because of the ineficient use of spectrum with a fixed pattern in the traditional WDM optical network,this paper focuses on the research of the Because of the ineficient use of spectrum with a fixed pattern in the traditional WDM optical network,this paper focuses on the research of the spectrum of flexible optical network based on virtualization technology research.spectrum of flexible optical network based on virtualization technology research.Because of the ineficient use of spectrum with a fixed pattern in the traditional WDM optical network,this paper focuses on the research of the spectrum of flexible optical network based on virtualization technology research.spectrum of flexible optical network based on virtualization technology research. It is the main direction of this paper how to utilize the elasticity of spectral flexible optical network to realize the efficient use of spectral resources in the optical network virtualization. The main work is as follows:First, with the Software Defined Network (SDN), this paper proposes a transmission network virtualization architecture based on the flexible spectrum optical network. Through the hierarchical abstraction of the architecture, the transmission network can realize the function of coordinating and distributing the cross-layer and cross-domain resources.And with the OpenFlow protocol, the parameters of the network devices can be centrally and automatically configurated.Second, aiming at the problem of collaborative optimization with the cross-layer resources in data centers, this paper proposes a network virtualization architecture, which takes into account of the application requirements in data centers and the characteristics of the optical transmission network. The paper introduces a method of the cooperation among multiple OpenFlow controllers,extends the OpenFlow protocol and complete the design and implementation of function modules in the architecture of optical network virtualization based on the cooperative optimization of cross-layer network resources. By analyzing the requirements of applications in the current data center, the resource status in the IP packet network, and the network status of the optical transport network, the resource allocation mode is optimized to meet the requirements of current services, thereby enhancing the speed of service responses and the utilization efficiency of network resources.Third, This paper proposes an optical network virtualization mapping strategy based on normalized cut. The purpose of this strategy is that the virtual optical network request is considered as a whole, not divided into independent "end to end" mapping problems.So it is possible to find a mapping scheme that optimizes the topology of the virtual optical network in consideration of the whole network, preventing the"local optimum but global worst" situation.