Virtual network embedding problem is the key problem in network virtualization, previous research mostly focus on the mapping of virtual network link, however, the physical node resource is also limit. In this paper, the authors propose a virtual network mapping with two stages based on node splitting. In our mapping, a virtual node is hosted by multiple physical nodes and a virtual link can map into a substrate path or paths by the link splitting based on the mapped nodes. The whole mapping can use resource fragments of physical nodes and links effectively, improve the resource utilization rate of physical network and promote the mapping efficiency of virtual network.
