Integrated Service Digital Network (ISDN); Signalling System No. 7 (SS7); Bearer Independent Call Control (BICC) - Signalling procedures in an ATM/IP/.. backbone network; Capability Set 1 (CS1) - Part 1: Protocol specification (ITU-T Recommendations Q.1901 and Q.765.5, modified) (Endorsement of the English version EN 301848-1 V 1.1.1 (2001-02) as German Standard)