UGC NET · PAPER 2
UGC NET Paper 2 Computer Science – Unit 9: Data Communication and Computer Networks PYQ (June 2023)
Q8. A TCP server application is programmed to listen on port P on host S. A TCP client is connected to the server over the network. While the TCP connection is active, the server crashes and reboots. Assume the client does not use the TCP keepalive timer. Which of the following behaviours is/are possible?
Statement I: The TCP server application on S can listen on P after reboot.
Statement II: If the client sends a packet after the server reboot, it will receive an RST segment.
Statement I: The TCP server application on S can listen on P after reboot.
Statement II: If the client sends a packet after the server reboot, it will receive an RST segment.
- Both Statement I and Statement II are correct
- Both Statement I and Statement II are incorrect
- Statement I is correct but Statement II is incorrect
- Statement I is incorrect but Statement II is correct
Q22. Match List I with List II
| List I | List II |
|---|---|
| A. Physical Layer | I. Transforming the raw bits into frames for transmission |
| B. Data Link Layer | II. Control and monitoring of the subnet |
| C. Network Layer | III. Transmission of raw bits over the communication channel |
| D. Transport Layer | IV. Transmission of data, connection-oriented or connectionless (datagrams) |
- A-III, B-II, C-I, D-IV
- A-II, B-III, C-I, D-IV
- A-III, B-I, C-II, D-IV
- A-II, B-IV, C-I, D-III
Q39. Match List I with List II
| List I | List II |
|---|---|
| A. CDMA | I. Provides mobile internet connection with faster data transfer rates |
| B. GSM | II. Allows users to connect to a network or to other devices over a wireless channel |
| C. UMTS | III. Access mechanism for multiple transmitters over a single channel |
| D. WiFi | IV. Cellular technology employing a hybrid of FDMA and TDMA |
- A-III, B-IV, C-II, D-I
- A-III, B-IV, C-I, D-II
- A-II, B-III, C-IV, D-I
- A-II, B-I, C-IV, D-III
Q55. Hosts P and Q are connected through a router R. The MTU of link P–R is 1500 bytes and of link R–Q is 820 bytes. A TCP segment of 1400 bytes is transferred from P to Q through R with IP identification 0x1234. The IP header is 20 bytes and the DF flag is not set. Which of the following statements are true?
A. Two fragments are created at R, and the IP datagram carrying the second fragment is 620 bytes.
B. If the second fragment is lost, R resends the fragment with IP identification 0x1234.
C. If the second fragment is lost, P has to resend the entire TCP segment.
D. The TCP destination port can be determined by analysing the second fragment only.
Choose the correct answer from the options given below:
A. Two fragments are created at R, and the IP datagram carrying the second fragment is 620 bytes.
B. If the second fragment is lost, R resends the fragment with IP identification 0x1234.
C. If the second fragment is lost, P has to resend the entire TCP segment.
D. The TCP destination port can be determined by analysing the second fragment only.
Choose the correct answer from the options given below:
- A, B and C only
- A and C only
- C and D only
- B and D only
Q81. In standard Ethernet with a transmission rate of 10 Mbps, the length of the medium is 2500 m and the frame size is 512 bits. The propagation speed of a signal in the cable is 2 × 10⁸ m/s. The transmission delay and propagation delay are
- 25.25 μs and 51.2 μs
- 51.2 μs and 12.5 μs
- 10.24 μs and 50.12 μs
- 12.5 μs and 51.2 μs
Directions (Q96–100): An IP datagram has arrived with the following partial header information (in hexadecimal): 45000054 00030000 2006…
Q97. What is the protocol of the payload being carried by the packet?
- ICMP
- SCTP
- TCP
- IGMP