gen-define-tcp-versus-udp-and-give-one-short-worked-example-8470

Define TCP versus UDP and give one short worked example.

# TCP vs UDP ## **TCP (Transmission Control Protocol)** - **Connection-oriented**: Establishes a connection before data transfer - **Reliable**: Guarantees delivery, order, and error-checking - **Slower**: Due to overhead from acknowledgments and retransmissions - **Use cases**: Web browsing, email, file transfers ## **UDP (User Datagram Protocol)** - **Connectionless**: Sends data without establishing a connection - **Unreliable**: No guarantee of delivery or order - **Faster**: Minimal overhead, no acknowledgments - **Use cases**: Video streaming, online gaming, DNS queries --- ## **Worked Example: Sending "HELLO" (5 packets)** ### **TCP Process:** 1. Sender → Receiver: SYN (establish connection) 2. Receiver → Sender: SYN-ACK 3. Sender → Receiver: ACK (connection established) 4. Sender transmits: H, E, L, L, O (each with sequence number) 5. Receiver sends ACK for each packet received 6. If packet 3 (L) is lost → Receiver requests retransmission 7. Connection closed with FIN handshake **Result**: "HELLO" arrives complete and in order ✓ ### **UDP Process:** 1. Sender transmits: H, E, L, L, O (fire and forget) 2. No acknowledgments 3. If packet 3 (L) is lost → Nothing happens **Result**: "HELO" might arrive incomplete or out of order (e.g., "HELOL") ✗ --- **Summary**: Use TCP when accuracy matters; use UDP when speed matters more than perfection.