What is a three-way handshake in TCP?

What is a three-way handshake in TCP?

• A. A method to establish a reliable connection between sender and receiver before data transfer.
• B. A method to terminate a connection.
• C. A method to synchronize clocks.
• D. A method to negotiate encryption.

Answer: (A)

A TCP three-way handshake is the process used to establish a reliable, connection-oriented link between two endpoints before any data is exchanged. It starts with the client sending a segment that has the SYN flag set and an initial sequence number, signaling a request to open a connection. The server replies with a segment that has both the SYN and ACK flags set, acknowledging the client’s sequence number and providing its own initial sequence number. The client then sends a final ACK to acknowledge the server’s sequence number. Once this exchange completes, both sides know the other is ready and have the necessary sequence numbers to support reliable, in-order delivery and retransmission if needed. This handshake is not for terminating a connection, syncing clocks, or negotiating encryption (those are handled by other mechanisms or layers).

A TCP three-way handshake is the process used to establish a reliable, connection-oriented link between two endpoints before any data is exchanged. It starts with the client sending a segment that has the SYN flag set and an initial sequence number, signaling a request to open a connection. The server replies with a segment that has both the SYN and ACK flags set, acknowledging the client’s sequence number and providing its own initial sequence number. The client then sends a final ACK to acknowledge the server’s sequence number. Once this exchange completes, both sides know the other is ready and have the necessary sequence numbers to support reliable, in-order delivery and retransmission if needed. This handshake is not for terminating a connection, syncing clocks, or negotiating encryption (those are handled by other mechanisms or layers).