DIN ETS 300770-1:2000-01
Действует
Broadband Integrated Services Digital Network (B-ISDN) - Digital Subscriber Signalling System No. two (DSS2) protocol - Closed User Group (CUG) supplementary service - Part 1: Protocol specification (ITU-T Q.2955.1:1996, modified) (Endorsement of the English version ETS 300770-1:1998 as German standard)
