Dictionary · Networking Fundamentals
Three-Way Handshake
Transport · Intermediate
The exchange that establishes a reliable transport connection: the initiator sends SYN, the responder sends SYN-ACK, and the initiator sends ACK.
Both sides agree on starting sequence numbers before application data flows. If the exchange never finishes, the application conversation does not really start.
Picture it
Both sides agree on starting numbers before application data flows. A simple datagram lookup does not use this exchange.
Example: A capture shows SYN from the client, SYN-ACK from the server, and ACK from the client before the first request.
Common misconception
- This exchange belongs to reliable transport. A datagram protocol such as a simple name lookup does not use it.