TCP vs UDP

TCP/IP Model

• Focus on transport layer
• Two primary protocols: TCP and UDP

Key Choice for Network Applications

• Reliable vs Unreliable transmission

Transmission Control Protocol (TCP)

• Reliable: Can resend and resolve missing or corrupted data
• Data Sent in Segments: Collects and reorders segments at receiving end
• Prevents Corrupt Files: Recovers lost segments

Reliable Connection

1. Acknowledgement Numbers: Ensures data received correctly
2. Sequence Numbers: Numbers segments for reordering and detection of missing pieces
3. Checksum: Detects errors by comparing calculations on both ends

Three-Way Handshake

1. Sender sends SYN (synchronize)
2. Receiver replies with SYN-ACK (synchronize-acknowledge)
3. Sender replies with ACK (acknowledge)

• Opens TCP connection

Sequence Numbers & Acknowledgement

• Sequence Numbers: Assigns to segments for correct reordering
• Acknowledgement Numbers: Receiver acknowledges receipt of segments

Checksum

• Calculation run against data on both ends
• Detects and discards corrupted segments

TCP Header Fields

• Port numbers: (covered in another video)
• Sequence and Acknowledgement numbers
• Checksum

User Datagram Protocol (UDP)

• Unreliable: No error handling, sequencing, or reliability
• Fast Transmission: Sends data quickly without concern for loss
• Minimal Header Information: Port numbers, length, and checksum
• Use Case: Live real-time connections (e.g., voice calls, video calls, gaming)

Comparison

• TCP: Reliable, resource-heavy, adds latency, ideal for web browsing, file transfers
• UDP: Unreliable, fast, minimal latency, ideal for real-time communication

Conclusion

• Two methods for two purposes: TCP for reliability, UDP for speed

Further Learning

• Mention of full CCNA course for more in-depth information

Call to Action

• Like, comment, subscribe