Home / Standards / GB/T 3380-1982 GB/T 3380-1982 Active Ringing and tone for telephone automatic switching network 电话自动交换网铃流和信号音 Standard Type GBT ICS 33.040.30 CCS M12 Status 现行 Issue Date 1982-12-29 Implementation 1983-10-01 Responsible Dept 工业和信息化部（通信） Drafting Unit N/A