A Scalable, Accurate and Extensible Network Emulation Platform Using the IXP1200 Network Processor
Emulab, the Utah Network testbed, is a large-scale emulation environment available to researchers all over the world. Through automated experiment configuration, and features such as dynamically changing link, router, and traffic characteristics, Emulab brings much of a simulator's ease of use and control to emulation while retaining its realism. PCs serve many roles in the testbed: as end-hosts in an emulated distributed system, as traffic generation and consumption nodes, as routers in the emulated topology, and as link emulator nodes. As link emulators, their capacity is limited to 1 or 2 100 Mb ethernet lines per box, largely due to PCI bus arbitration overhead which negatively impacts scaling to large topologies.