(19)

(11)

EP 0 722 643 A1

(12)

(43) Date of publication: 24.07.1996 Bulletin 1996/30 (21) Application number: 94928489.0 (22) Date of filing: 07.10.1994

(51) International Patent Classification (IPC):  H04L 12/ 24( . ) H04Q 3/ 00( . ) (86) International application number: PCT/GB1994/002190 (87) International publication number: WO 1995/010149 (13.04.1995 Gazette 1995/16)

(84) Designated Contracting States: BE CH DE DK ES FR GB IT LI NL PT SE (30) Priority: 07.10.1993 GB 19930020641 14.04.1994 EP 19940302673 (71) Applicant: BRITISH TELECOMMUNICATIONS public limited company London EC1A 7AJ (GB)	(72) Inventor: JOHNSON, David Ipswich Suffolk IP5 7SN (GB) (74) Representative: Semos, Robert Ernest Vickers, et al  BT Group Legal Services, Intellectual Property Department, 120 Holborn London EC1N 2TE London EC1N 2TE (GB)