TCP against UDP — OS, DBMS & Networks Aptitude Question
TCP against UDP: Which of these statements about TCP is false? Answer and worked solution on CodeKairo.
- Topic: OS, DBMS & Networks
- Section: Programming MCQs
- Difficulty: Medium
- Time target: 90 seconds
Question
Which of these statements about TCP is false?
Options
- It is connection oriented
- It delivers bytes to the application in order
- It has a minimum header size of 8 bytes
- It provides flow control through a receiver-advertised window
Show the answer and the worked solution
Correct answer: C. It has a minimum header size of 8 bytes
Worked solution
- TCP opens a connection with a three-way handshake, numbers every byte so the receiver can rebuild the stream in order, and advertises a window for flow control — three true statements.
- TCP's header is 20 bytes without options, because it carries sequence and acknowledgement numbers, a window size, flags and a checksum.
- The 8-byte header belongs to UDP, which carries only source port, destination port, length and checksum, so It has a minimum header size of 8 bytes is the false statement.
Answer: It has a minimum header size of 8 bytes.
The idea
Header sizes are the quickest way to remember the difference: 20 bytes of guarantees against 8 bytes of best effort. UDP wins where latency beats reliability — DNS queries, live audio and video, gaming.
Shortcut. 8 bytes is UDP's header, four 2-byte fields; TCP's minimum is 20, and the other three statements are TCP's defining features.
Common trap. "It delivers bytes to the application in order" tempts because IP packets can arrive out of order, but TCP reorders them by sequence number.