Abstract: A new satellite network architecture based on SDN(Software Defined Networking)/NFV(Network Function Virtualization) co-deployment was proposed to solve the problem that the satellite network has limited load and does not allow the large-scale deployment of physical hardware,which lead to the lack of network functions and flexible network management and configuration.It carries out dynamic control of the network through the idea of SDN data layer and control layer separation,and uses NFV technology to create network functions in the data plane of SDN,so that network functions can be decoupled from hardware devices.In this way,network flexibility can be effectively improved.In order to solve the problems that the VNF (virtual network function) in this framework maps to the underlying physical network with excessive delay and cannot meet the real-time perfor-anceof the high dynamic satellite network,a dynamic mapping method named VG-DPA (Viterbi and GPM Dynamic Placement Approach) based on Viterbi and GPM (graph pattern matching) was further proposed.This algorithm first models the mapping process as a hidden Markov service chain through the estimator,and then uses Viterbi algorithm to obtain the mapping path that meets all the hardware and software constraints.Then,based on the estimator results,VNF scheduling strategy is developed by means of GPM.This algorithm solves the problem of mapping the required VNF to the underlying physical network in the highly dynamic satellite network with excessive time delay.Simulation results show that VG-DPA can greatly reduce the time delay and resource consumption compared with the traditional RAND and OMD algorithms.

Key words: Dynamic mapping method, Graph model matching, Hidden Markov chain, Network Function Virtualization, Satellite network, Software Defined Networking, Viterbi algorithm