Future internets escape the simulator

Cloud computing researchers confront a similar dilemma. In order to maintain uniformity and efficiency in their data centers, commercial cloud providers generally do not provide ?under the hood? controls that permit modification to the underlying network topology or protocols that comprise the cloud environment. Because IPv6 deployment affects components throughout the Internet, years of extensive review, planning, and coordination have been required to ensure a smooth, if slow, transition. For researchers contemplating more fundamental innovations, such as non-IP protocols or new routing approaches, the barriers are correspondingly higher. Establishing a FIDC testbed of meaningful scale requires a significant investment of money and effort. Exclusive use is generally not feasible, so virtualization quickly becomes a practical necessity to support a sizable research community.