What Is the Real Difference Between TCP and UDP? Protocol Comparison with Real-Life Examples

Table of Contents

• Scene Opens: Inside the Network Arena
• Round 1: Reliability
• Round 2: Speed
• Round 4: Use Case Comparison Table
• Protocols Using TCP, UDP, or Both – With Port Numbers
• Use Case: Netflix vs Gaming
• TCP/UDP in Cybersecurity
•  Conclusion
•  Frequently Asked Questions (FAQs)

 Scene Opens: Inside the Network Arena

Two tech legends stand on opposite sides of the ring — TCP, the reliable and well-organized communicator, and UDP, the fast and fearless speedster.

They both transmit data across the internet, but the way they do it is drastically different. Let's dive into this fun face-off and understand which protocol wins depending on the real-world situation.

Round 1: Reliability

TCP (Transmission Control Protocol):
"I'm all about making sure every piece of data arrives safely. I check for errors, track packets, and even resend missing ones. You can trust me — I'm the protocol behind emails, websites, and file downloads."

UDP (User Datagram Protocol):
"You're too slow! I focus on speed over perfection. I don’t need connection setups or acknowledgments. That’s why I’m great for live video, voice calls, and gaming."

Round 2: Speed

UDP:
"I send data without asking for permission — that’s why gamers love me. No time wasted!"

TCP:
"Sure, you’re fast, but in critical communication, speed without structure is risky. I take time to build a secure connection first."

Round 3: Error Handling

TCP:
"If any part of your message is lost, I go back and retrieve it. That’s why banking apps and websites trust me."

UDP:
"I skip that step to keep things moving fast. If a few packets drop during a video stream, it's barely noticeable!"

Round 4: Use Case Comparison Table

Protocols Using TCP, UDP, or Both – With Port Numbers

Here’s a breakdown of real-world protocols and how they relate to TCP and UDP, including their commonly used ports:

Use Case: Netflix vs Gaming

• Netflix (TCP):
  It buffers content using TCP to ensure no part of the video is missing or corrupted.

• Online Gaming (UDP):
  Games like PUBG and Valorant use UDP for lightning-fast data transmission, even if some packets are lost.

TCP/UDP in Cybersecurity

• TCP attacks:

  • SYN Floods

  • ACK Scans

• UDP attacks:

  • UDP Floods

  • Amplification (e.g., DNS, SNMP)

Understanding their behaviors is crucial for both offensive (pen testing) and defensive (firewall, IDS/IPS) cybersecurity roles.

✅ Conclusion: Who Wins the Battle?

There’s no true winner — it depends on the situation:

• Use TCP for reliability.

• Use UDP for speed.

Whether you’re streaming, gaming, running VoIP, or setting up a secure server, your protocol choice can make or break the experience.

 FAQs

What is TCP in networking?

TCP (Transmission Control Protocol) is a connection-based protocol used to ensure reliable delivery of data over the internet.

What is UDP used for?

UDP (User Datagram Protocol) is a faster, connectionless protocol commonly used in live video, gaming, and VoIP applications.

How is TCP different from UDP?

TCP guarantees delivery and order of packets, while UDP sends data without acknowledgments, prioritizing speed over reliability.

Is Netflix using TCP or UDP?

Netflix primarily uses TCP for video streaming to ensure complete and ordered delivery of video chunks.

Why is UDP used in online games?

UDP is preferred in gaming for its low latency and faster delivery, even if some packets are lost.

What port does TCP use?

TCP can use various ports. Common ones include 80 (HTTP), 443 (HTTPS), 21 (FTP), and 25 (SMTP).

What port does UDP use?

UDP uses ports like 53 (DNS), 161 (SNMP), and 69 (TFTP), among others.

Which is more secure: TCP or UDP?

TCP is considered more secure due to its connection-handling features, though both can be secured using additional layers like SSL/TLS.

Is DNS a TCP or UDP protocol?

DNS uses UDP for queries and TCP for zone transfers and large data responses.

Can UDP guarantee packet delivery?

No, UDP does not ensure delivery, order, or duplication protection.

Which protocol is better for VoIP — TCP or UDP?

UDP is better for VoIP as it reduces delay and latency, providing smoother voice transmission.

Is SMTP a TCP or UDP protocol?

SMTP uses TCP (port 25) to ensure email delivery is accurate and complete.

What protocol does SNMP use?

SNMP uses UDP, primarily on ports 161 and 162.

What is NetBIOS used for?

NetBIOS provides communication between Windows machines and uses both TCP and UDP (ports 137–139).

Which protocol is faster, TCP or UDP?

UDP is faster due to the absence of handshake and acknowledgment processes.

What does the TCP three-way handshake do?

It establishes a reliable connection between sender and receiver before transmitting data.

Does video calling use TCP or UDP?

Video calls generally use UDP for reduced latency and real-time delivery.

Can TCP handle real-time applications?

TCP is less ideal for real-time apps due to potential delays from retransmissions.

What is the difference in packet structure between TCP and UDP?

TCP packets are larger and contain more control information. UDP packets are smaller and simpler.

Can both TCP and UDP run on the same port?

Yes, TCP and UDP are separate protocols and can use the same port number for different services.

Which is used by FTP — TCP or UDP?

FTP uses TCP for both data (port 20) and control (port 21) connections.

Does LDAP use TCP or UDP?

LDAP can use both; TCP is commonly used on port 389.

Why is TCP better for file transfers?

TCP ensures that every byte is delivered correctly, which is essential for file integrity.

Is UDP connectionless?

Yes, UDP is connectionless and sends packets independently without confirmation.

What are the disadvantages of using UDP?

Lack of reliability, packet loss, and no acknowledgment or ordering features.

What is a SYN flood attack in TCP?

A type of DoS attack where fake TCP requests exhaust server resources by exploiting the handshake process.

What are common UDP-based attacks?

UDP floods, amplification attacks (e.g., via DNS or NTP), and spoofed traffic attacks.

Is TCP or UDP better for security logging?

TCP is better due to its reliability and order, especially in SIEM data transfers.

What is a TCP ACK scan?

It’s a technique used in network scanning to determine firewall rules or active hosts.

What tools can analyze TCP and UDP traffic?

Wireshark, Netcat, Zenmap, TCPdump, and Netstat are popular tools for protocol analysis.