(19)

(11)

EP 0 218 724 A1

(12)

(43) Date of publication: 22.04.1987 Bulletin 1987/17 (21) Application number: 86903726.0 (22) Date of filing: 10.04.1986

(51) International Patent Classification (IPC):  G06F 7/ 548( . ) G06F 17/ 17( . ) G06F 1/ 035( . ) (86) International application number: PCT/US1986/000735 (87) International publication number: WO 1986/006517 (06.11.1986 Gazette 1986/24)

(84) Designated Contracting States: BE DE FR GB IT NL (30) Priority: 22.04.1985 US 19850725921 (71) Applicant: AT&T Corp. New York, NY 10013-2412 (US)	(72) Inventor: GANAPATHY, Sundaram Middletown, NJ 07748 (US) (74) Representative: Watts, Christopher Malcolm Kelway, Dr., et al  AT&T (UK) Ltd. 5, Mornington Road Woodford Green Essex, IG8 0TU Woodford Green Essex, IG8 0TU (GB)