Characteristics and advantages of three data exchange methods.

1, there are three ways of data exchange: line exchange, message switching and packet exchange.

2. The first type: circuit switching. After the line is established and before it is released, even if there is no data to be transmitted between stations, other stations are still not allowed to share the whole line; Once the line is established, all resources (including line resources) of both communication parties are used for this communication, and there is no other delay except a small amount of transmission delay, which has good real-time performance; Circuit switching equipment is simple; Transparent transmission of user data. The second type: message exchange. The line is not exclusive, and the data of multiple users can enjoy a line by storing and queuing; And the utilization rate of the line is improved; Support multicast (a message is transmitted to multiple users, and an "address field" is added to the message, and intermediate nodes copy and forward according to the address field); The intermediate node can convert the data format to facilitate the collection of the receiving station; Error detection function is added to avoid unnecessary transmission of error data.

3. The third type: packet switching. It has the advantages of circuit switching and message switching. After each data packet is identified, dynamic multiplexing technology is used on the physical line to transmit multiple data packets at the same time; Packet switching has higher circuit utilization than circuit switching, shorter transmission delay and better interactivity than message switching.