1.5 TCP and UDP

Question 1

Define:

TCP

(Transmission Control Protocol)

Answer 1

A connection-oriented protocol ensuring reliable data transmission.

TCP establishes a connection, ensuring data integrity and successful delivery through error detection, acknowledgment, and retransmission.

Question 2

List the features of TCP.

Answer 2

1. Connection-oriented
2. Reliable data transfer
3. Ordered data delivery
4. Error checking and correction
5. Flow and congestion control

These features make TCP suitable for applications requiring reliable data delivery, such as web browsing and file transfers.

Question 3

Define:

UDP

(User Datagram Protocol)

Answer 3

A connectionless protocol with no delivery, order, or error guarantees.

UDP sends data without a connection, not ensuring order or delivery, making it suitable for speed-critical applications with acceptable data loss.

Question 4

List the features of UDP.

Answer 4

1. Connectionless
2. Unreliable transfer
3. Faster speeds
4. No error checking
5. No flow control

UDP is suitable for applications that prioritize speed, such as DNS queries or live video calls, where reliability can be compromised.

Question 5

In which OSI model layer do the protocols TCP and UDP operate?

Answer 5

Transport layer

Both TCP and UDP are found in the transport layer of the OSI model, where TCP is utilized for connection-oriented communication and UDP for connectionless communication.

Question 6

True or False:

TCP is faster than UDP.

Answer 6

False

TCP has higher overhead due to connection setup, error checking, and retransmissions, whereas UDP’s simplicity and minimal overhead allow for faster communication.

Question 7

What is the main difference in how TCP and UDP handle packet delivery?

Answer 7

• TCP: Uses a handshake and acknowledgment for packet delivery.
• UDP: Sends packets without connection or acknowledgment.

TCP’s connection-oriented nature ensures reliability, while UDP’s connectionless approach minimizes overhead for speed.

Question 8

Identify three applications that benefit from using UDP.

Answer 8

• Online gaming
• Video conferencing
• VoIP

UDP is preferable for applications where speed is critical and some data loss is acceptable, such as in online gaming, video conferencing, and voice over IP (VoIP).

Question 9

Why is UDP preferred for online gaming?

Answer 9

It is faster due to no acknowledgment or error checking.

Online gaming requires low latency, and slight packet loss is tolerable, whereas TCP’s overhead would introduce unacceptable delays.

Question 10

What is the three-way handshake in TCP?

Answer 10

A method to establish a reliable connection between sender and receiver.

The handshake involves SYN, SYN-ACK, and ACK steps to ensure both devices are ready for data transmission, ensuring reliability and no data loss.

Question 11

Fill in the blank:

TCP ensures data integrity through ____-________ ________.

Answer 11

error-recovery features

TCP includes error-checking and recovery mechanisms to ensure all packets are delivered correctly.

Question 12

How does TCP recognize lost data?

Answer 12

By using sequence numbers and acknowledgments.

If a segment is not received, the recipient requests the sender to resend it.

Question 13

Why is UDP preferred for DNS queries?

Answer 13

It is faster, and DNS queries require minimal data.

DNS requests are typically small, and speed is more important than reliability. Since DNS operates over short-lived connections, the lack of error-checking in UDP speeds up the query process.

Question 14

True or False:

UDP requires more bandwidth than TCP.

Answer 14

False

UDP requires less bandwidth because it does not include connection setup, acknowledgments, or error recovery, whereas TCP’s overhead consumes more bandwidth.