Research On Deterministic Orchestration Of Virtual Network Function Forwarding Graph

The core of 5G network is the service-oriented architecture based on cloud native,which can reconstruct the functions of traditional network equipment and provide service-oriented resource management,network orchestration and slicing services.The service in the telecommunication network is uncontrollable and statistically arrived,and the network scheduling is guided by the optimal resources.while the industrial Internet service presents the characteristics of small scale and certainty,5G cloud native system and service technology still face problems in ensuring industrial applications with strict timing,determinism and reliability requirements.The virtual network function forwarding graph is the main technical factor affecting this problem.Therefore,this thesis aims at the optimal service performance and studies the forwarding graph orchestration technology and method from the spatial dimension to the spatio-temporal dimension.The main contents are as follows:(1)First,this thesis explains the related concepts of 5G cloud native system,including the key technologies of servicing,virtualized architecture and virtual function forwarding graph.Secondly,it analyzes the classification and orchestration requirements of industrial applications,and discusses the mapping relationship of the5 G service-oriented structure when it is redeployed in the industrial Internet.Finally,this thesis presents a forwarding graph orchestration scheme which can guarantee end-to-end service transmission with strict time requirements,including high-level service scheduling and underlying resource scheduling.VNF-FG deterministic orchestration is regarded as a full integer programming problem,which can be decomposed into the transmission path selection of the whole process,the planning and control of residence time in VNF node input and internal function processing module VNFC.(2)Three key technologies are studied in the deterministic orchestration of forwarding graphs: path selection and residence time planning in the whole process,and residence time control of service flow in the input port and VNFC.1)This thesis first proposes a Non-workconserving full-path time coordination VNF-FG orchestration algorithm FTCO,which considers the temporal requirements of the business,and extends the forwarding graph from the topological orchestration of the spatial dimension to the joint optimization of the spatio-temporal dimension,thus realizing the path selection of the whole process and the planning of residence time.2)Further deploy the industrial network to the non-synchronous bearer network,propose a virtual time scheduling algorithm VTS at the VNF input port,VTS back-presses the uncertain delay jitter to the application layer to reorder,directly serves the synchronized business time to business orchestration and realizes quasi-synchronous scheduling;3)Finally,considering that there are still terminals with non-real-time operating systems in the industrial network.Even if it is virtualized as VNFC,it is difficult to guarantee the time consumption of the process planning when forwarding in the v CPU.Therefore,this thesis proposes a deterministic process scheduling algorithm based on emergency DUS,according to the planned residence time and the state of the process arriving at the node,assigns different urgency to the corresponding processes in each VNFC,dynamically arranges and adjusts the scheduling order of processes in each scheduling cycle,and completes the deterministic scheduling between different processes.(3)In this thesis,the effects of the three key technologies are simulated and verified,and the resource optimization-oriented orchestration algorithm provided in the open source Open Day Light project is used as a comparison.The results show that FTCO has the best performance in ensuring timely,punctual and collaborative services.VTS can drive the scheduling with the service clock,and can adjust the service network access timing at the application layer,so as to realize the planned input end stay time in the non-synchronized bearer network.Compared with priority algorithm,DUS can eliminate delay jitter or smooth burst jitter.The scheduling position between processes is changed in the VNFC module to ensure the specified waiting time,thereby supporting the full process and deterministic orchestration capability of end-to-end services.