The document discusses next-generation network virtualization. It describes how VPNs and server virtualization/cloud computing are influencing network virtualization. New applications require integration of these technologies and greater network support. The approach presented is to create a system that allows users to set up combinations of computing and networking resources based on a high-level specification. Key innovations needed include a language for specifying application needs, algorithms for provisioning resources, a virtualized router that can run multiple protocol stacks in parallel, and a software foundation.