Research And Implementation Of Efficient Availability-Guaranteed Network Function Virtualization Embedding Problem

Network Function Virtualization(NFV),as an important technology in next generation network,is a promising way to address bottleneck in traditional network.NFV decouples physical network equipment from the network functions that run on them,and implement these network functions in commodity hosts.The main idea of NFV is leveraging virtualization technology to design,embed and manage customized networking services.A main challenge in the implement of NFV is resource allocation of demanded network services in NFV-based network infrastructures.In this paper,we focus on the second stage of the resource allocation problem,what we called Network Function Virtualization Embedding(NFVE)problem.While availability is one of key metrics in Service Level Agreement(SLA),we focus on the Availability-guaranteed Network Function Virtualization Embedding(ANFVE)problem and use backup to ensure network availability.In this thesis,we carefully study the ANFVE problems.We summarize the related work of NFVE problem and analyze the critical factors of ANFVE problem.Most of the existing works assume that virtual network functions need to be embedded in different servers.In this paper,the phenomenon of multiple virtual network functions embedded in one server is called superposition.We consider both how to efficiently and reliably embed NFV when superposition is allowed and not allowed.Specifically,when superposition is not allowed,we study the impact of the diversity of virtual network functions and servers on ANFVE problem,and propose a novel scheme to quantify the impact of virtual network functions and servers diversity.We model the problem as a non-linear 0-1 programming problem,and propose a heuristic,which leverage virtual network functions and servers diversity to improve the efficiency of NFV embedding.When superposition is allowed,we thoroughly analyze the effect of allowing superposition in ANFVE problem,including effect on availability,link consumption and dependency.We thoroughly analyze the challenges in realizing superposition,including some constraints on superposition,propose the principle of link design and availability calculation.We model the problem as a non-linear 0-1 programming problem,and propose a heuristic to allow superposition and minimize the resource consumption under availability constraints.In this paper,a comparative experiment is made with the proposed algorithm and the existing work.The results show that the proposed work can greatly improve availability and resource utilization for NFV.