DIN EN 300363-2004 专用综合业务网(PISN).规范、功能模型和信息流.无干扰和无干扰补偿补充业务
Private Integrated Services Network (PISN) - Specification, functional model and information flows - Do not disturb and do not disturb override supplementary services [ISO/IEC 14842 (1996) modified] (Endorsement of the English version EN 300363 V1.3.1 (20