ICS33.040.20M19GB中华人民共和国国家标准GB/T17789-1999eqv ITU-T V.70:1996在PSTN或二线点对点租用电话型电路上同时传送数据和数字化编码语音信号的规程Procedures for simultaneous transmission of data anddigitally encoded voice signals over the PSTN or over2-wire leased point-to-point telephone type circuits1999-07-13发布2000-01-01实施国家质量技术监督局发布
