A Packet Switch to Serve One Million Households

Dr. Sandy Fraser

Fraser Research

Friday, February 27, 2004
10:30am - SENSQ 5317
Refreshments at 10am in SENSQ 5319

Abstract

A topdown study of a network for 100 million households suggests a much simpler network topology than is presently evolving for the Internet. Just as Federal Express discovered that computer networks and air transport enable a more efficient centralized architecture for package delivery, so it is apparent that fiber and the practicality of very high capacity switches point the way to a more efficient communications infrastructure. The question until now has been whether switches of sufficient capacity can be constructed. This talk seeks to show that indeed they can.

Clos and Benes developed the principles which enabled large telephone switches to be made from many small switches. In recent years the study of large packet switches has found inspiration in the work of Clos and Benes even though their analytic results do not apply in a packet switched world. The problem is that bad traffic patterns cause points of severe congestion and it is hard to manage large and diverse traffic flows without triggering significant side- effects, like loss of proper sequence in the delivered data.

Quite by accident an organizing principle for large switching networks has been found. Simulation results confirm the possibilities. In this talk the underlying principle will be explained and there will be discussion of simulation results for a machine to serve 256,000 homes. Simple calculations lead to the belief that switches with capacity in excess of 1 Pb/sec are practical.

Bio Sketch

Alexander G. Fraser, known as "Sandy", established Fraser Research after his retirement from AT&T. Fraser arrived at AT&T Bell Laboratories in 1969 and while there invented the DataKit Virtual Circuit Switch and the Spider ring network, both of which are cell-based networks that anticipated the development of Asynchronous Transfer Mode (ATM). He created the UNIX Circuit Design Aids System, which automatically produced wire-wrap circuit boards from schematic circuit diagrams. In 1994 Fraser became Associate Vice President for Information Science Research where he focused on research initiatives including electronic commerce for digital audio, billing, broadband access and home networks.

Before joining Bell Labs, Fraser was Assistant Director of Research at Cambridge University where he wrote the file system for the Atlas 2 computer, England's first time-sharing system, and developed file back-up and privacy mechanisms for that system. Earlier work includes a language and compiler for commercial data processing written for the Ferranti Orion computer.

Fraser has a B.Sc. degree in Aeronautical Engineering from Bristol University and received his Ph.D. in Computing Science from Cambridge University. He is an IEEE Fellow, a member of ACM and was a Fellow and council member of the British Computer Society. In 2001 Dr. Fraser received IEEE's Richard W. Hamming Medal "for pioneering contributions to the architecture of communication networks through the development of virtual circuit switching technology".