the working principles of transmission control (TCP)

Unlike the Internet Protocol (IP), TCP has the working principles of such "virtual circuit" in the telephone network. TCP more important governance-how and reliability in the delivery of data between two computers in the network. TCP does not care with what is done by IP, is an important communication link between two computers running well. In this case, how do I set up a TCP connection to open communication, the type of application is to be conducted in the communication (for example to send e-mail, file transfer etc.). In addition, to detect and edit the data if there is a mistake. Manage the entire process of a TCP connection between one computer with another computer in a computer network.
Unlike the IP connectionless mechanisms that rely on the TCP connection is a connection mechanism oriented. In this case, the relationship of logic will be built by TCP between one computer with another computer. Time specified in the computer is connected to send data or must acknowledge that the relationship still held. If this is not able to do so can be assumed that the computer that we are dealing with broken relationships and the logic can be closed.
TCP multiplexing set of data sent / received by a computer. There is an identification in the TCP header allows multiplexing is done. This allows a computer to do some of the TCP connection logic. Form of relationship is full duplex, this allows two computers to talk each other in the same time without having to use alternate communication channel. To overcome the saturation (congestion) on the communication channel, the TCP header includes information about flow control.
It is important to understand is the TCP port number. Determine the port number of the services performed by application programs over TCP. Numbers have been determined by the Network Information Center in the Request For Comment (RFC) 1010 [10]. As an example application for File Transfer Protocol (FTP) over transport layer TCP port number 20 is used and many more.
Working principle of TCP based on the principle of client-server. Server is a program on the computer that will passively listen (listen) port number that was specified in the TCP. Medium client is a program that actively opens a TCP connection to the server computer to request the service required.
client will actively open the connection (active open) by sending a signal Syn (Syn SENT state) to the destination server computer. If the server receives the signal Syn server at that time are on the LISTEN state akan Syn and send signals to two computers (client & server) akan to ESTAB state. If no response from the computer that dituju, the program will return to the state CLOSE. After the service has been completed then the client will send the wrong signals FIN and the client computer will be in state FIN WAIT signal until FIN received from the server. At the time of receiving signals FIN, the server will be to CLOSE WAIT state relationship to be. Finally, the second computer will be back in the state CLOSE.