The establishment steps of the server and the client under the TCP blocking model:
The establishment steps of the server:
1. Call socket to establish a TCP socket
2. Call bind to bind the socket to the local address
3. Call listen to establish monitoring
4. Establish accept to receive The client's connection returns a new connection socket.
5. On the new socket, call send/recv to realize the communication with the client. The
client's establishment steps:
1. Call socket to establish a TCP socket
2. Server connection
3. Call send/recv to communicate with the server
