TCPühendus

TCPühendus, often referred to as a TCP connection, is a fundamental concept in computer networking. It is a mechanism for reliable data transfer between two devices over an Internet Protocol (IP) network. TCP, which stands for Transmission Control Protocol, ensures that data is delivered in the correct order and without errors.

Before any data can be exchanged, a TCPühendus must first be established. This process, known as the "three-way handshake," involves three distinct steps. The client initiates the connection by sending a SYN (synchronize) packet to the server. The server, upon receiving the SYN packet, responds with a SYN-ACK (synchronize-acknowledgment) packet. Finally, the client sends an ACK (acknowledgment) packet back to the server, confirming the connection. Once this handshake is complete, the TCPühendus is considered established.

During the connection, TCP employs various mechanisms to guarantee reliability. This includes sequencing of data packets, so they can be reassembled in the correct order at the receiving end, and acknowledgments, where the receiver confirms receipt of each packet. If a packet is lost or corrupted, TCP will retransmit it. Flow control is also managed, preventing a fast sender from overwhelming a slow receiver.

When the data transfer is complete, the TCPühendus must be terminated. This typically involves a four-way handshake where both parties exchange FIN (finish) and ACK packets to signal that they are done sending data and wish to close the connection. This orderly closure ensures that all data has been transmitted and acknowledged. TCPühendus is crucial for applications like web browsing, email, and file transfer, where data integrity and order are paramount.