Telephone switching system
local (urban) telephone switching system
Stored program-control telephone switching system
Switching System
切换系统
开关系统
交换系统
转接系统
开关设置
专接装置
立接制长途电话交换机
Telephone Switching Network
Signal Switching System
telephone switching equipment
telephone switching device
digital telephone switching
telephone switching center
sequence switching system
virtual switching system
Remote switching system
office telephone switching
private telephone switching
automatic data editing and switching system
Automatic Switching System
Digital telephone switching network