线路忙 CONGESTION ; Line busy ; the line is engaged

忙线路 [计] [通信] Busy Channel ; [计] [通信] busy line

线路忙音 line busy tone

通讯线路忙 Line is busy

全忙线路 [通信] all busy circuit

线路忙线中 The line is busy

繁忙的铁路线 busy railway line