Data Communication and Computer Networks – Previous Year Questions
241 questions from past UGC NET Paper 2 – Computer Science papers, each with the correct answer. Open any question for its explanation.
- Sequence the following stages of the sliding window protocol for flow control. A. Sender moves the window to the next set of frames. B. Sender sends a window of frames. C. Receiver acknowledges the received frames. D. I…
- The primary function of a firewall in network security is
- Match List I with List IIList I List II A. Service Level Agreement I. The technology that connects and enables communication between physical devices over the Internet. B. Virtualization II. A development environment pr…
- Choose the correct statements from the following A. In connection-oriented service, the destination address is to be specified only during the setup. B. Packet sequencing is not guaranteed in connection-oriented service…
- Arrange the following steps of the DHCP (Dynamic Host Configuration Protocol) process in the correct sequence. A. DHCP ACK B. DHCP DISCOVER C. DHCP OFFER D. DHCP REQUEST E. Client receives IP configuration Choose the co…
- In a token ring network the transmission speed is 10⁷ bps and the propagation speed is 200 m/μs. The 1-bit delay in this network is equivalent to
- Match List I with List IIList I List II (A) Representation of bits (I) Transport layer (B) Physical Address (II) Physical layer (C) Logical Address (III) Network layer (D) Segmentation and reassembly (IV) Data link layer
- Consider a CSMA/CD network that transmits data at 100 Mbps over a 1 km cable with no repeater. If the minimum frame size required for this network is 1250 bytes, what is the signal speed (km/sec) in the cable?
- Host A (on a TCP/IPv4 network) sends an IP datagram D to host B (also on a TCP/IPv4 network). Assume no error occurred during transmission of D. When D reaches B, which of the following header fields may differ from tho…
- Match List I (IP Address) with List II (Class)List I List II (A) 10.20.30.40 (I) Class E (B) 210.20.30.3 (II) Class B (C) 180.30.100.10 (III) Class A (D) 252.5.15.11 (IV) Class C
- Arrange the following steps in proper sequence for the typical process of a DNS query: (A) Query authoritative DNS server (B) Query local DNS server (C) Local DNS server checks cache (D) Query root DNS server (E) Query…
- A class B network on the Internet has a subnet mask of 255.255.248.0. What is the maximum number of hosts per subnet?
- Consider the three-way handshake during TCP connection establishment between hosts A and B. Let S and R be the random 32-bit initial sequence numbers chosen by A and B respectively. A sends a TCP segment with SYN = 1, S…
- Two computers A and B are configured as follows: A has IP address 203.197.2.53 and subnet mask 255.255.128.0; B has IP address 203.197.75.201 and subnet mask 255.255.192.0. Which one of the following statements is true?
- Consider the following statements: (A) In IPv4 addressing, a block of addresses can be defined as x.y.z.t/n, in which x.y.z.t defines one of the addresses and /n defines the mask. (B) The first address in the block can…
- Hash functions are used to produce message digests which are then encrypted with a private key to get:
- A multiplexer combines four 100 Kbps channels using a time slot of 2 bits. What is the bit rate?
- Which of the following is NOT a field in the TCP header?
- In bit stuffing, each frame begins and ends with which bit pattern (in hexadecimal)?
- Which of the following are examples of CSMA channel-sensing (persistence) methods? (A) 1-persistent (B) 2-persistent (C) p-persistent (D) non-persistent Choose the correct answer from the options given below:
- The work done by UDP is/are: (A) Congestion control (B) Flow control (C) Retransmission (D) Segment transmission Choose the correct answer from the options given below:
- Which of the following statements is/are NOT CORRECT? (A) OSPF is based on the distance-vector routing protocol. (B) Both link-state and distance-vector routing are based on the least-cost goal. (C) BGP4 is based on the…
- Which of the following statements are CORRECT? (A) NRZ is a bipolar scheme in which a positive voltage defines bit 0. (B) NRZ-L and NRZ-I both have an average signal rate of N/2. (C) The ideas of RZ and NRZ-L are combin…
- Match List I with List IIList I List II (a) Monoalphabetic cipher (I) Round key (b) DES (II) One-to-many relationship (c) Stream cipher (III) One-to-one relationship (d) Polyalphabetic cipher (IV) Feedback mechanism
- Arrange the following steps in the correct order for a DHCP client to renew its IP lease with a DHCP server: (a) DHCP client sends a DHCPREQUEST message (b) DHCP server acknowledges the renewal with a DHCPACK message (c…
- Statement (I): In datagram networks, routers hold state information about connections. Statement (II): In a virtual-circuit network, each virtual circuit requires router table space per connection. In the light of the a…
- 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…
- Match List I with List IIList 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 b…
- Match List I with List IIList 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…
- 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 head…