Tcp Ip Protocol Questions Long
The process of connection termination using TCP's four-way handshake involves a series of steps to ensure a graceful closure of the connection between two communicating hosts. The four-way handshake is initiated by either the client or the server, and both parties exchange control messages to terminate the connection.
1. Connection termination request:
The party initiating the termination, known as the active closer, sends a TCP segment with the FIN (Finish) flag set to 1 to the other party. This segment indicates that the sender has no more data to send and wants to terminate the connection. The active closer enters the FIN_WAIT_1 state.
2. Acknowledgment of termination request:
Upon receiving the FIN segment, the receiving party, known as the passive closer, acknowledges the termination request by sending an ACK (Acknowledgment) segment back to the active closer. The passive closer enters the CLOSE_WAIT state, indicating that it is waiting for its own application to close the connection.
3. Data transfer completion:
The passive closer continues to send any remaining data it has to the active closer. Once all the data has been transmitted, the passive closer sends a FIN segment to the active closer, indicating that it has finished sending data and wants to terminate the connection. The passive closer enters the LAST_ACK state.
4. Connection termination acknowledgment:
Upon receiving the FIN segment, the active closer acknowledges the termination request by sending an ACK segment back to the passive closer. The active closer enters the TIME_WAIT state, which is a short period during which it waits to ensure that the acknowledgment is received by the passive closer. After this period, the active closer transitions to the CLOSED state, and the connection is fully terminated.
It is important to note that the TIME_WAIT state is necessary to handle any delayed segments that may still be in transit. This ensures that the active closer does not prematurely close the connection before all segments have been properly processed.
Overall, the four-way handshake in TCP connection termination ensures that both parties have completed their data transfer and are aware of the termination request, allowing for a reliable and orderly closure of the connection.