VXDL: virtual resources and interconnection networks description language Data grid applications require often an access to infrastructures with high performance data movement facilities coordinated with computational resources. Other applications need interconnections of large scale instruments with HPC platforms. In these context, dynamic provisioning of customized computing and networking infrastructure as well as resource virtualization are appealing technologies. Therefore new models and tools must be studied and developed to allow users create and handle such on-demand virtual infrastructures within grid platforms or even within the Internet. This work presents VXDL, a language for virtual resources interconnection networks specification and modeling. Besides allowing end resources description, VXDL lets users describe the desirable virtual network topology, including virtual routers and timeline. In this paper we motivate and present the key features of our modeling language. We explore typical examples to demonstrates the expressiveness and the pertinence of it. Then we detail experimental results based on the execution of NAS benchmark on virtual infrastructures, conforming different VXDL specifications.