网络功能虚拟化下服务功能链的资源管理研究综述

伴随着云计算，软件定义网络和网络功能虚拟化等网络新技术的出现，未来网络运维向着虚拟化、智能化的方向不断迈进.网络功能虚拟化提供了一种服务节点虚拟化的方法，它采用通用服务器替代传统网络中的专用中间件，可以大大降低网络运营商的建设和运营成本，提升网络管理的灵活性和可扩展性.由于网络端到端服务通常需要不同的服务功能,采用虚拟化技术构建网络服务功能链，进行资源的合理分配和调度成为一个重要的研究课题，引起了学术界和工业界的广泛关注.从网络功能虚拟化的技术背景出发，介绍了网络功能虚拟化下服务功能链资源管理的基础架构、技术基础和应用场景.而后基于服务功能链编排的不同阶段，将现有理论研究划分为4个部分：组链、部署、调度和按需缩放分别展开论述，从问题出发介绍和分析了研究现状.最后，针对现有存在问题，提出了一些拟解决方案，并对未来的研究方向进行了展望.

Resource Management of Service Function Chain in NFV Enabled Network :A Survey

With the emergence of new network technologies such as cloud computing,software-defined network(SDN)and network function virtualization(NFV),the future network s management is supposed to become virtual and intelligent.NFV provides an approach to realize service functions based on the virtualization technology,and it adopts general servers to substitute the dedicated middlebox in traditional network,which is able to greatly reduce the capital expenditure(CAPEX)and the operating expense(OPEX)of the telecom service provider(TSP).NFV can also improve flexibility and scalability in the management of network services.Since the end-to-end network services are usually composed of different service functions,it is an important research topic to adopt virtualization technology to build service function chain(SFC)and reasonably allocate and schedule resources.In this paper,based on the background of NFV technology,we introduce the infrastructure,technical basis,and application scenarios of SFC in the NFV enabled network.Afterward,we mainly focus on the different stages of SFC orchestration:SFC composition,SFC placement,SFC scheduling,and SFC adaptive scaling.The correlated existing theoretical research is summarized.Finally,in view of the existing problems,some solutions are proposed and the future research directions are prospected.