Private Integrated Services Network (PISN) - Inter-exchange signalling protocol - Advice of charge supplementary services (ISO/IEC 15050 (2003), modified) (Endorsement of the English version EN 301264 V1.2.1 (2004-01) as German standard)
专用综合业务网(PISN).交换间信令协议.收费通知补充业务(ISO/IEC 15050(2003) 修改)(认可英文版EN 301264 V1.2.1(2004-01)为德国标准)