What is a program-controlled telephone? What is a program-controlled switch?

Program-controlled telephone refers to the telephone connected to the program-controlled telephone exchange. Program-controlled telephone exchange is an exchange controlled by electronic computer. It uses pre-programmed programs to control the follow-up actions of the exchange. Compared with the general electromechanical exchange telephone, this program-controlled telephone has the advantages of fast connection speed, multiple business functions, high exchange efficiency, clear voice and reliable quality.

Program-controlled exchange, also known as program-controlled private branch exchange or digital program-controlled exchange, usually refers to the switching equipment used in telephone switching network, which uses computer programs to control the connection of telephones.

Digital program-controlled switches are divided into long-distance switches and local switches. There are also types dedicated to signaling networks and intelligent networks.

The basic functions of digital program-controlled exchange are: subscriber line access, relay connection, billing, equipment management, etc.

The local exchange automatically detects the user's off-hook action, sends back a dial tone to the user's phone, receives the pulse signal or DTMF signal generated by the phone, and then completes the connection from the calling party to the called party (the called party may be in the same exchange or in a different exchange). After the connection is completed, the switch will remain connected until it detects that the communication party hangs up.