Delay-tolerant network protocol testing and evaluation Delay-tolerant networks, DTNs, are characterized by lacking end-to-end paths between communication sources and destinations. A variety of routing schemes have been proposed to provide communication services in DTNs, and credible and flexible protocol evaluation tools are in demand in order to test these DTN routing schemes. By examining the evolution of DTN protocol testing and evaluation, this article discusses the trend toward large-scale mobility trace supported emulation, and we propose TUNIE, a large-scale emulation testbed for DTN protocol evaluation based on network virtualization. Unlike the existing simulation tools and real-life testbeds, which either cannot provide a realistic DTN environment setup or are too costly and time-consuming, our proposed TUNIE architecture is capable of simulating reliable DTN environments and obtaining an accurate system performance evaluation. By system prototype and implementation, we demonstrate TUNIE as a flexible platform for evaluating DTNprotocol performance.