Private Integrated Services Network (PISN) - Service description, functional capabilities and information flows - Circuit-mode 64 kbit/s bearer services [ISO/IEC 11574 (2000) modified] (Endorsement of the English version EN 300171 V1.3.1 (2003-06) as German standard)
专用综合业务网(PISN).业务描述 功能能力和信息流.电路模式64kbit/s承载业务[ISO/IEC 11574(2000)修改](认可英文版EN 300171 V1.3.1(2003-06)为德国标准)