Service Function Chain Deployment For Ultra Wide Granularity

With the continuous emergence of new types of network services,as well as the massive promotion of online video and other services,the network traffic has exploded.However,traditional communication networks rely on the characteristics of dedicated and enclosed hardware devices,making network expansion and the development and deployment of new services difficult.Network function virtualization(NFV)realizes the use of virtualization software and cheap general-purpose computing devices to provide various network functions through the decoupling of software and hardware.A network service can generally be decomposed into a combination of multiple network functions,and the service flow flows through each network function middleware in order to obtain the corresponding network service.This set of network function sequences is called the service function chain(SFC).How to deploy the service function chain to the underlying physical network is the key research content of NFV technology.In the face of services with a wide range of bandwidth requirements,the packet-switched network can flexibly provide transmission services for services with small bandwidth requirements,but it is difficult to independently carry services with large bandwidth requirements.Optical switching networks can be used to carry bandwidth-intensive services,but there are obvious shortcomings in the provision of fine-grained bandwidth services and real-time connection establishment.Therefore,this thesis will introduce the optoelectronic hybrid network to coordinate the bandwidth supply of the underlying network to the business,so that the business can obtain the expected service,thereby improving the ability of the network to carry the business.The photoelectric hybrid network combines the flexibility of the packet switching network and the advantages of the large bandwidth of the optical switching network to provide a more flexible and efficient underlying switching network for ultra-wide granular business requirements.This thesis has done an in-depth study on how to optimize the SFC mapping deployment plan in the optoelectronic hybrid network and realize the mutual benefit and win-win situation of customers and operators through resource allocation.This thesis first studied the joint optimization problem of service function chain mapping and routing in the optoelectronic hybrid network under static offline scenarios,and established an integer linear programming model.On this basis,this thesis analyzes how to apply the random rounding algorithm to quickly solve the problem,and at the same time gives a clear performance analysis of the algorithm.Following this,aiming at the shortcomings of the feasibility of the random rounding algorithm,an improved heuristic algorithm is designed.The simulation results show that under the condition of ensuring the feasibility of the mapping scheme,the result of the improved algorithm is very close to the optimal solution.Then this thesis studies the dynamic online scene of SFC's continuous arrival and departure in the optoelectronic hybrid network.Based on the bandwidth and calculation requirements of SFC,this thesis creates a corresponding ILP model for solving the problem of the mapping scheme of a single SFC in the underlying network.And designed an approximate solution algorithm based on the reconstruction auxiliary graph to improve the network reception rate and reduce the mapping overhead,and finally completed the simulation experiment analysis of the approximate algorithm.