If it is a persistent connection, I don't close the connection. I do use those types of connections for things like transmitting control data from a joystick or the like. It is a bit harder to maintain that type connection.
Normal port 80 web traffic is a "connect-request-reply-disconnect" type communication. The server does not close the connection until it has sent the last packet, and the client code reads all the characters from the rx buffer. The client.stop on the client end tells the server you received everything and closes the connection.