中華人民共和國國家標準
NATIONAL
STANDARD OF THE PEOPLE'S REPUBLIC OF CHINA
GB/T 7621-1987
1200 bits per second duplex modem standardized for use in the general switched telephone network and on point-to-point 2-wire leased telephonecircuits 在電話自動交換網和點對點二線租用電話型電路上使用的標準化的1200比特/秒雙工調制解調器
Issued Date:1987-04-03
Implemented Date:1987-11-01
Issued by:
The Standardization Administration of the People's Republic of China