为了吸纳业务的不确定性并将业务网络灵活高效地映射到数据中心的物理网络中，研究了弹性光数据中心网络中业务模型为软管模型的动态虚拟数据中心映射问题。首先建立了软管虚拟机在弹性光数据中心网络中的映射模型，然后提出了基于虚拟拓扑图的虚拟机放置算法（VT-VMPA）。VT-VMPA首先将软管模型转化为管道模型，再由业务量最大化原则寻找核心虚拟机。然后按照业务量降序，将满足资源约束条件且与核心虚拟机相连的虚拟机合并成簇，以减少簇映射到服务器后的通信带宽需求。最后将构成簇集按跳距自适应和最短路径原则映射到弹性光数据中心网络的服务器和光路上。仿真结果显示，该算法与其他算法相比，平均带宽消耗减少了21%、阻塞率减少了27%、时间平均收益提高了117%。这表明该算法能够降低网络带宽资源的消耗、提高网络映射率。

To absorb the traffic uncertainty and map the service network to the physical network of the data center flexibly and efficiently, this paper studies the dynamic virtual data center mapping problem in an elastic optical data center network, where the service model is a hose model. First, the mapping model of a flexible virtual machine is established in an elastic optical data center network, and then the virtual machine placement algorithm based on virtual topology (VT-VMPA) is proposed. The VT-VMPA first converts the hose model into the pipe model before looking for the core virtual machine using the maximization of traffic volume as a guideline. Then, in descending order of service volume, the virtual machines that adhere to the resource constraints and are linked to the core virtual machines are combined into clusters. The communication bandwidth requirement is reduced after the cluster is mapped to the server. Finally, the cluster sets are mapped to the servers and virtual links between clusters are mapped to optical paths of the elastic optical data center network according to hop distance adaptive and shortest path principles. In comparison to previous methods, the proposed algorithm has decreased blocking rate by 27%, increased average time revenue by 117%, and decreased average bandwidth usage by 21%. It demonstrates that this method may increase network mapping speed while consuming fewer network traffic.