Topology Research In Optical Network Virtualization

As a key technology to solve the problem of current network capacity shortage and"network ossification",optical network virtualization plays an important role in the utilization of network resources.Virtual optical network(VON)fault recovery is a key issue in optical network virtualization applications,which has a great impact on the efficiency of optical network virtualization.In addition,with the development of new services such as Autopilot and Internet of Vehicles that have extremely high requirements on network speed and network delay,the recovery time of virtual optical networks is crucial.In this paper,we focuses on the problem of virtual optical network fault recovery,and propose two virtual optical network fault recovery algorithms PP-VON-RA and PPRCP-VON-RA based on non-backup resource to solve the fault recovery time of VON by studying the underlying topology in the virtualization process.Compared with the typical re-routing recovery algorithm without backup resources,the recovery time is shortened by more than 60%,which greatly reduces the overall delay of the network.The main work and innovations of this paper include the following four aspects:(1)A topological analysis algorithm DFSTAA based on depth-first search is proposed.By analyzing the underlying topological characteristics of the optical network virtualization process and abstracting it into a simple combination of the ring and chain model,a DFS-based topology analysis algorithm DFSTAA is designed.The algorithm can efficiently search the ring chain structure in the network for the clear reproduction of complex topologies.(2)A virtual optical network recovery algorithm PP-VON-RA based on P-cycle protection mechanism is proposed.Pre-computation is performed by the DFSTAA algorithm to protect each link in the underlying network SN with a P-cycle mechanism to quickly recover link faults in the virtual optical network.The algorithm greatly reduces the recovery time of the faulty virtual optical network and reduces the network delay.(3)The recovery algorithm PPRCP-VON-RA of P-cycle priority re-routing cooperative protection is proposed.The algorithm weighs the recovery time and recovery success rate.The recovery time is reduced by 6 1%while ensuring a high recovery success rate.(4)For the virtual optical network request of different services,the concept of business recovery tolerance BRT(Business Recovery tolerance)is proposed.For the VON services of different BRTs,a guiding scheme for applying the protection recovery algorithm is given to optimize the user experience.