TCP vs UDP comparison in Computer Networks - Practice Questions

Challenge - 5 Problems

❓ Comparison

intermediate

Key Difference Between TCP and UDP

Which of the following best describes a fundamental difference between TCP and UDP?

A UDP establishes a connection before sending data; TCP sends data without establishing a connection.

B TCP is connection-oriented, ensuring reliable data transfer; UDP is connectionless and does not guarantee delivery.

C TCP is faster than UDP because it has less overhead.

D UDP guarantees data order and error checking, while TCP does not.

💡 Hint

Think about whether the protocols establish a connection and how they handle data delivery.

TCP (Transmission Control Protocol) sets up a connection and ensures data arrives correctly and in order. UDP (User Datagram Protocol) sends data without setting up a connection and does not guarantee delivery or order.

🧠 Conceptual

intermediate

Use Cases for UDP

Why might an application choose UDP over TCP?

A Because UDP is faster and suitable for real-time applications where speed is more important than reliability.

B Because UDP provides guaranteed delivery and error correction.

C Because UDP requires a connection setup which improves security.

D Because UDP automatically resends lost packets.

💡 Hint

Consider applications like live video or gaming where delays are bad.

UDP is faster because it skips connection setup and error checking. This makes it good for real-time apps where speed matters more than perfect accuracy.

📋 Factual

advanced

Port Numbers in TCP and UDP

Which statement about port numbers in TCP and UDP is correct?

A Port numbers are not used in UDP.

B TCP and UDP use completely different port number ranges.

C A port number can only be used by either TCP or UDP, never both.

D TCP and UDP can use the same port numbers independently for different services.

💡 Hint

Think about how services like DNS use UDP and TCP on the same port number.

TCP and UDP each have their own port spaces, so the same port number can be used by both protocols independently for different services.

❓ Reasoning

advanced

Impact of Protocol Choice on Data Transmission

If a file transfer application uses UDP instead of TCP, what is the most likely outcome?

A The file will always transfer faster and without errors.

B The file transfer will be slower because UDP adds extra error checking.

C The file may transfer faster but could be incomplete or corrupted due to lost packets.

D The file transfer will be secure because UDP encrypts data by default.

💡 Hint

Consider what UDP does not provide compared to TCP.

UDP does not guarantee delivery or order, so some data may be lost or arrive out of order, causing incomplete or corrupted files.

🔍 Analysis

expert

Analyzing Protocol Behavior Under Network Congestion

During heavy network congestion, how do TCP and UDP behave differently?

A TCP reduces its sending rate to avoid congestion; UDP continues sending at the same rate regardless of congestion.

B UDP reduces its sending rate to avoid congestion; TCP continues sending at the same rate regardless of congestion.

C Both TCP and UDP reduce their sending rates equally during congestion.

D Neither TCP nor UDP adjust their sending rates during congestion.

💡 Hint

Think about which protocol is designed to be 'friendly' to the network.

TCP uses congestion control to slow down when the network is busy, helping prevent overload. UDP does not have built-in congestion control and keeps sending data at the same speed.