What is the data exchange mode of traditional telephone network?

Traditional telephone networks use circuit switching.

CS: Circuit switching (CS) is the earliest and most widely used switching mode in communication networks. It is mainly used to complete telephone exchange in telephone communication network, with a history of 100 years.

The process of telephone communication is as follows: firstly, off-hook, dial after hearing the dial tone, the switch searches for the called party, rings the called party and sends back the ring tone to the calling party, which indicates that a two-way voice transmission path has been established between the calling party and the called party in the telephone network; When the called party picks up the phone, it can enter the call stage; During the call, if either party hangs up, the switch will destroy the established call path and send a busy tone to remind the other party to hang up, thus ending the call.

From the description of telephone communication process, we can see that telephone communication is divided into three stages: call establishment, call and call demolition. The process of telephone communication is the process of circuit exchange, so the basic process of corresponding circuit exchange can be divided into three stages: connection establishment, information transmission and connection release.

Main features:

1, and the minimum unit of information transmission is time slot;

2. Connection-oriented;

3. Synchronous time division multiplexing;

4. Error-free control of information transmission;

5. Flow control based on call loss;

6. Information is transparent. Characteristics of circuit switching: ((In circuit switching, the circuit may be fixed or established as needed. )

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