网络虚拟化环境中虚拟网络的嵌套映射算法

Virtual Network Embedding Algorithms in the Network Virtualization Environment

网络虚拟化技术可以在共用的底层网络基础设施上同时构建多个彼此隔离的虚拟网络,为用户提供差异化服务,从而解决现有因特网的僵化问题.然而,一个重要的挑战是,如何在共用的基础设施中高效地映射多个具有不同拓扑的虚拟网络,即虚拟网络的嵌套映射问题.主要根据基础设施的构成方式对现有的虚拟网络映射算法进行了综述.首先,阐述了网络虚拟化的概念、特点以及相应的虚拟网络映射模型;其次,按照基础设施的构成方式、问题空间完整性、映射阶段数等方面梳理了嵌套映射算法的最新研究进展;最后,对虚拟网络映射算法在公平性、扩展性、高利用率、信任度等未来可能的发展方向进行了展望.

Network virtualization allows multiple isolated virtual networks to run simultaneously on a shared substrate infrastructure to provide diversifying services to the end user, solving the Internet ossification problem. However, a major challenge is efficiently mapping multiple virtual networks with different topologies into a shared infrastruture, named the virtual network embedding problem. This paper surveys the current literature primarily according to the composition of the infrastructure. Firstly, the concept and feature of network virtualizations are elaborated, and the corresponding model of virtual network embedding is formulated. Secondly, the latest research progress of virtual network embedding algorithms is reviewed according to the composing way of infrastructure, the integrity of problem space, the number of embedding stage and so on. Finally, the potential future research directions are outlined in the aspects of fairness, scalability, high utilization and trust.