网络虚拟化是未来网络的关键技术之一,有助于克服当前网络的“僵化”问题,能够在无须对当前网络架构进行巨大改变的基础上配置新的网络协议和服务,实现多个虚拟网络共存于一个物理网络上,由此产生了新的问题,如何将有限的物理资源合理分配给不同的虚拟网络,即虚拟网络映射问题.根据网络环境,分为有线网络和无线网络下的虚拟网络映射.其中,有线网络下的映射是研究虚拟网络映射问题的基础和重点,已有大量算法提出.为了给该问题的研究提供一个全面的视野,从问题定义、存在挑战、映射目标方面对有线网络中虚拟网络映射算法进行综述,根据算法的不同特点进行分类,重点介绍几种典型的算法并进行比较总结,最后指出未来的研究趋势.
Network virtual ization is recognized as a key technology for the future Internet. It helps to overcome the ossificationproblem on the current network and can evaluate new protocols and services without the need current network architecture. As a resul t, mult iple virtual networks ( VNs) share the same physical network and new problemoccurs which is how to allocate l imited physical resources to multiple VNs in a reasonable and effective way,namely virtual net-work embedding ( VNE) problem. According to the network environment, VNE includes embedding in wired network and inwireless network. VNE in wired network; is the foundation and the key of VNE problem. A To provide a comprehensive view of the problem,this paper presented a survey of current VNE algorithms in wired network from the aspects of the def inition of the problem,the challenges and embedding objects. It proposed the classificationrithms according to their characteristics and compared several typical VNE algorithms. At last,it discustrends.