intra-office trunk [通信] 局内中继线 ; 局内中继 ; 局内中断线

intra office trunk 局内中继 ; 局内里继

cross office trunk 局内中继线

iot intra office trunk 局内中继

Central Office Trunk Interface Circuit 局端接口电路

two way operator office trunk 双向操作人员用局内中继线

central office line trunk 局间中继线

trunk central office 交换局干线