CCNA (200-301) - 1.5 - Compare TCP to UDP (TCP vs. UDP)
TCP vs. UDP
A simple guide to the internet's two most common data delivery services.
TCP
The Reliable Messenger
Think of TCP as a certified mail service. It's built for **accuracy** and **reliability**, ensuring every piece of data arrives safe, sound, and in the correct order.
Key Features:
- ✓ Establishes a connection first (handshake).
- ✓ Guarantees delivery and re-sends lost data.
- ✓ Ensures data is ordered correctly.
Best for:
Web Browsing, Email, File Transfers
UDP
The Speedy Postcard
Think of UDP as sending a postcard. It's all about **speed** and **efficiency**. It sends data immediately without any guarantees, making it incredibly fast.
Key Features:
- ✗ No connection required; just sends data.
- ✗ No guaranteed delivery or error checking.
- ✗ Data can arrive out of order or not at all.
Best for:
Live Streaming, Online Gaming, DNS
At a Glance
| Feature | TCP | UDP |
|---|---|---|
| Connection | Required (Handshake) | Connectionless |
| Reliability | High (Guaranteed) | Low (Best-Effort) |
| Ordering | Ordered Sequence | No Ordering |
| Speed | Slower (More Overhead) | Faster (Less Overhead) |
