I. Introduction
With the rapid development of data center, cloud computing, Internet of things and other technologies, the rigidity of traditional network architecture has become increasingly prominent [1]. Operators abstract the physical network into multiple independent virtual networks through network function virtualization technology [2] to share their physical resources, and deploy services according to the diversified needs of users. Due to the dynamic loading of network functions and the realization of on-demand allocation of network resources [3], accelerating the innovation and application of network technology, network virtualization has become an effective way to solve the existing network problems. Under the virtual environment, there is unbalanced traffic load distribution in the underlying optical network [4]. The traditional load balancing mapping method [5]–[8] only considers the absolute load balance of links or nodes, and does not consider the network topology factors such as key nodes and key links of the network, which results in the problem of heavy load at key nodes of the optical network and low request acceptance rate of the virtual network. This paper proposes a virtual mapping method of optical network based on topology awareness, which can provide differentiated load balancing guarantee for virtual network services in the underlying optical network, provide reliable and stable solutions for optical network virtualization, and improve the support ability of software defined optical network technology for multi services.