WANCE: A wide area network communication emulation system

Experimentation in wide area computer networks such as the Internet is difficult. One difficulty is the lack of experimental hosts for individual researches or research groups. The authors have developed a new approach to overcome this problem. The approach is to emulate a remote site using one local machine, and to emulate a true Internet communication environment in a local area network, by rotating the inter-site communication through actual Internet hosts. This approach provides a way to conduct experiments with large scale geographically dispersed distributed systems without any designated experimental sites except for the local ones. The authors have studied this approach and observed that it is feasible and reliable. They have realized this approach in a communication package called the WANCE tool, which can be used to experiment distributed software in this new approach. They have also evaluated this approach by comparing it with real experiments, using a distributed database application. The relative errors they measured are within 3%.