24.7. Connectionless Client/Server Interaction with Datagrams
We have been discussing connection-oriented, streams-based transmission. Now we consider connectionless transmission with datagrams.
Connection-oriented transmission is like the telephone system in which you dial and are given a connection to the telephone of the person with whom you wish to communicate. The connection is maintained for the duration of your phone call, even when you are not talking.
Connectionless transmission with datagrams is more like the way mail is carried via the postal service. If a large message will not fit in one envelope, you break it into separate message pieces that you place in separate, sequentially numbered envelopes. Each of the letters is then mailed ...