1 A Large-Scale Network and Distributed Systems Testbed Jay Lepreau Chris Alfeld David Andersen (MIT) Kristin Wright University of Utah December 14, 1999

2 What? A configurable Internet in a room Ü220 nodes, 1000 links, BFS (switch) Üvirtualizable topology, links, software An instrument for experimental CS research Universally available to any remote experimenter Simple to use

3 Why? “We evaluated our system on five nodes.” -job talk from university with 300-node cluster “We evaluated our Web proxy design with 10 clients on 100Mbit ethernet.” “Simulation results indicate...” “Memory and CPU demands on the individual nodes were not measured, but we believe will be modest.” “The authors ignore interrupt handling overhead in their evaluation, which likely dominates all other costs.” “Resource control remains an open problem.”

4 Why 2 “You have to know the right people to get access to the cluster.” “The cluster is hard to use.” “ runs FreeBSD 2.2.x.” “October’s schedule for is…” “ is tunneled through the Internet”

5 Complementary to Other Experimental Environments Simulation Small static testbeds Live networks Maybe someday, a large scale set of distributed small testbeds (“Access”)

6 Roatan: Remote Console for a Node

7 A Few Research Issues and Challenges Calibration, validation, and scaling Artifact detection and control NP-hard virtual --> physical mapping problem Providing a reasonable user interface ….

8 Final Remarks Should be limping next month Looking for early users Sponsors: University of Utah, Novell, DARPA, Compaq, Nortel,