Lesson 25: TCP vs. UDP: Choosing the Right Protocol
Understanding the trade-offs between TCP and UDP is fundamental to network design and troubleshooting.
Direct Comparison Table
| Feature | TCP (Transmission Control Protocol) | UDP (User Datagram Protocol) |
|---|---|---|
| Reliability | High (Guaranteed Delivery) | Low (Best-Effort Delivery) |
| Overhead | High (Requires headers, ACKs, retransmissions) | Low (Minimal header) |
| Connection Type | Connection-Oriented (3-way handshake required) | Connectionless (No handshake) |
| Data Unit | Segment | Datagram |
| Flow Control | Yes (Using windowing) | No |
| Error Control | Yes (Sequencing and checksums) | Minimal (Checksum only) |
| Use Cases | Web pages, file transfer, email, database access | Streaming video/audio, online gaming, DNS lookups |
Practical Application Scenario
- Downloading a bank statement: You must use TCP. If even one bit is missing, the financial document is incorrect or corrupted.
- Video conferencing: You use UDP for the video stream. If a packet is lost, the video momentarily glitches, but receiving the correct data one second later is pointless (it's already old). Prioritizing speed ensures smooth real-time conversation.
Rule of Thumb: If data integrity is paramount, use TCP. If low latency and high speed are paramount, use UDP.