Broadband Integrated Services Digital Network (B-ISDN) - Signalling System No. 7; B-ISDN User Part (B-ISUP) - Part 2: Network node interface specification for point-to-multipoint call/connection control [ITU-T Recommendation Q.2722.1 (1996)] (Endorsement of the English version EN 301029-2 V 1.1.2 (1998-04) as German standard)