What is three-way handshake? Full Explained

The three-way handshake is a process used in network communication to establish a connection between two devices over a TCP/IP network. It is a key mechanism for initiating a reliable and orderly data exchange.

The three-way handshake involves three steps or messages exchanged between the devices:

1. Step 1: SYN (Synchronize)

• The process begins with the client, which is the device initiating the connection, sending a SYN packet to the server, the device receiving the connection request.
• The SYN packet contains a randomly generated sequence number to initiate the connection.

1. Step 2: SYN-ACK (Synchronize-Acknowledge)

• Upon receiving the SYN packet, the server responds with a SYN-ACK packet.
• The SYN-ACK packet acknowledges the client's SYN packet and also includes its own randomly generated sequence number.
• The server allocates buffers and resources to handle the incoming connection.

1. Step 3: ACK (Acknowledge)

• Finally, the client sends an ACK packet back to the server, confirming the receipt of the server's SYN-ACK packet.
• The ACK packet also acknowledges the server's sequence number.
• At this point, the connection is established, and both devices can begin exchanging data.

The three-way handshake ensures that both devices agree on initial sequence numbers, synchronize their internal variables, and confirm their readiness to communicate. It establishes a reliable and ordered connection before the actual data transmission starts.

By completing the three-way handshake, both devices establish a connection that allows for error detection, flow control, and reliable data delivery. It is a fundamental process in the TCP/IP protocol suite and is widely used in applications that require a reliable and robust network communication.

Sourse: ChatGpt