What is the method used by TCP to establish a connection?

The method used by TCP to establish a connection is known as the Three-Way-Handshake. This process is fundamental to how TCP (Transmission Control Protocol) initiates communication between two devices over a network.

During the Three-Way-Handshake, the client and server engage in a series of messages to establish a connection. The steps involved include:

1. SYN (synchronize): The client sends a SYN packet to the server to request a connection, indicating its initial sequence number.
2. SYN-ACK (synchronize-acknowledge): The server responds with a SYN-ACK packet, acknowledging the client's request and providing its own initial sequence number.
3. ACK (acknowledge): Finally, the client sends an ACK packet back to the server, confirming receipt of the server's SYN-ACK.

Once this exchange is complete, a reliable, bidirectional connection is established, enabling data transmission between the client and server. The key point of this method is that it ensures both parties are ready to communicate and have synchronized their sequence numbers, which is crucial for data integrity and order during the transmission.

This process differentiates it from methods like single-step connection, two-step verification, or concepts like connection-final