Research On Service Orchestration In Network Function Virtualization

In 2012,network function virtualization,as a novel idea to reconstruct network,is proposed by a group of telecommunication network service providers.The basic idea of network function virtualization seeks to replace traditional dedicated network hardware by custom servers,so as to decouple network function with dedicated hardware.The key problem of network function virtualization is how to do orchestration for service function chain.In this dissertation,three problems about service function chain orchestration are studied: 1)high utilization problem;2)fairness problem and 3)performance guarantee problem.In the research about high utilization problem,both experiments and theoretical analysis show that it is easy to happen that inefficient virtual network function instances sprawl across network in network function virtualization environment.This phenomenon will result in low utilization problem.To address it,the system can consolidate those network function demands with same type and assign on less instances.Based on it,network function consolidation algorithm is designed to improve system utilization,and various simulations are conducted to verify our algorithm.In the research about fairness problem,it is found that service function chain involves multiple resources with correlation.Therefore,this work modifies fairness problem in service function chain as a multi-resource fairness mode.By studying the disadvantages of previous solutions,this work designs service function chain oriented multi-resource fairness,which can satisfy overlap sharing scenario of service function chains.Moreover,it is presented the property proofs for this policy in the work.In the research about performance guarantee problem,it is found that the orchestration schemes have deep influence on fairness policy allocation results,which further affect basic performance of service function chain.Thus,this work considers a joint problem that combines service function chain orchestration with fairness policy and model it as an optimization problem.Based on it,this work designs performance guarantee aware service function chain orchestration algorithm.The simulation results show that our algorithm greatly outperforms existing solutions.