DIN ETS 300356-9:1995-11
Отменен
Integrated Services Digital Network (ISDN) - Signalling System No. 7; ISDN User Part (ISUP) version 2 for the international interface - Part 9: Closed User Group (CUG) supplementary service [ITU-T Recommendation Q.735, clause 1 (1993), modified]; English version ETS 300356-9:1995
