The concept of network virtualization has attracted increasing attention by researchers designing and modeling the next-generation Internet paradigm. Researchers need a new type of hybrid network to construct experimental environments for testing new services, architecture, and technologies, especially network protocols, without affecting existing traffic. This paper presents our work on implementing a large-scale testbed that has been created over production networks by integrating novel technologies such as cloud computing, software defined networking, and virtual switches. This approach provides researchers with an experimental networking testbed where traffic can be controlled via programmable virtual switches and dynamic adjustability for many types of network emulation experiments. This system also provides a feasible solution for the networking requirements of federated cloud system.