Process of three-way handshaking protocol
Step 1 (SYN): In the first step, the client wants to establish a connection with the server, so it sends a segment with SYN(Synchronize Sequence Number) which informs the server that the client is likely to start communication and with what sequence number it starts segments.
Step 2 (SYN + ACK): Server responds to the client request with the SYN-ACK signal bits set. Acknowledgment (ACK) signifies the response of the segment it received and SYN signifies with what sequence number it is likely to start the segment.
Step 3 (ACK): In the final part, the client acknowledges the response of the server and they both establish a reliable connection with which they will start the actual data transfer.
Steps 1, 2 establish the connection parameter (sequence number) for one direction and it is acknowledged. Steps 2, 3 establish the connection parameter (sequence number) for the other direction and it is acknowledged. With these, full-duplex communication is established.
