A New LAN Concept for the LEP Machine Network:
A Step towards LHC

L. Guerrero, P. Lienard
CERN - 1211 Geneva 23 - CH


LEP networks, implemented in 1987, are based on two Token- Ring backbones using TDM as the transmission medium. The general topology is based on routers and on a distributed backbone. The new concept relies on a large infrastructure which connects all the eight underground pits of LEP with single- mode fibers from the Prevessin Control Room (PCR). FDDI has been selected as the MAC Protocol. The new concept is based on switching and routing between the PCR and the eight pits. It will provide for workgroups organization and bandwidth allocation. The technological choices allow a possible future evolution towards ATM and 100Base Ethernet and preserve a large part of the investment. This paper describes the implementation of this scheme and the first results of its operation.