Preparing for your B.Tech Computer Networks exam? One of the best ways to prepare is to review previous year questions (PYQs). It helps you understand common patterns, important topics, and the format of the exam.
We’ve compiled the mandatory objective questions (Q1) from several past B.Tech exam papers. Review them, test your knowledge, and good luck with your studies!
2023 (B.Tech 7th Sem)
1. (a) Flow control is the responsibility of?
- (i) Data Link Layer
- (ii) Transport Layer
- (iii) Both (a) and (b)
- (iv) Application LayerAnswer: (iii) Both (a) and (b)
1. (b) Which one of the following layers of abstraction is not present in the TCP/IP model but is included in the OSI model?
- (i) Network layer.
- (ii) Transport layer.
- (iii) Session layer
- (iv) Application layer.Answer: (iii) Session layer
1. (c) How many bits are required to represent IPv4 address in any IPv4 header?
- (i) 64 bits.
- (ii) 32 bits.
- (iii) 16 bits.
- (iv) 8 bits.Answer: (ii) 32 bits.
1. (d) Which one of the following functionalities do TCP and UDP have in common?
- (i) In-order delivery.
- (ii) Reliable transfer.
- (iii) Checksum.
- (iv) Connection establishment.Answer: (iii) Checksum.
1. (e) What type of application would prefer UDP transport service?
- (i) Video conferencing.
- (ii) World Wide Web (WWW)..
- (iii) Online chess game.
- (iv) Email.Answer: (i) Video conferencing.
1. (f) Which one of the following statements is true about Go-Back-N (GBN) protocol?
- (i) Sequence number in GBN needs to be at least twice as large as the window size.
- (ii) GBN uses multiple timers.
- (iii) GBN retransmits packets upon receiving duplicate acknowledgements.
- (iv) GBN discards packets that are received out of order.Answer: (iv) GBN discards packets that are received out of order.
1. (g) Which one of the following statements is true about Selective Repeat (SR) protocol?
- (i) SR receiver sends duplicate acknowledgement for all packets that are not expected.
- (ii) SR uses multiple timers.
- (iii) SR retransmits packets upon receiving duplicate acknowledgements.
- (iv) SR uses cumulative acknowledgement.Answer: (ii) SR uses multiple timers.
1. (h) Which one of the following statements is true about TCP’s “Slow Start” algorithm?
- (i) TCP’s congestion window size increases linearly.
- (ii) TCP’s congestion window size decreases linearly.
- (iii) TCP’s congestion window size increases exponentially.
- (iv) TCP’s congestion window size decreases exponentially.Answer: (iii) TCP’s congestion window size increases exponentially.
1. (i) In which computer network topology, a single cable is used, through which all data propagates and to which all computers and networked nodes are connected?
- (i) Star.
- (ii) Bus
- (iii) Ring.
- (iv) Mesh.Answer: (ii) Bus
1. (j) Bluetooth is the wireless technology for –
- (i) Personal area network
- (ii) Local area network.
- (iii) Metropolitan area network.
- (iv) Wide area network.Answer: (i) Personal area network
2023 (B.Tech 6th Sem)
1. (a) In an optical fiber, the inner core is ___ the cladding.
- (i) denser than
- (ii) less dense than
- (iii) the same density as
- (iv) another name forAnswer: (i) denser than (Optically denser, with a higher refractive index)
1. (b) Sliding window protocol is used for
- (i) error control
- (ii) session control
- (iii) flow control
- (iv) concurrency controlAnswer: (iii) flow control (and error control)
1. (c) Connection-establishment involves a ___-way handshake in TCP.
- (i) one
- (ii) two
- (iii) three
- (iv) fourAnswer: (iii) three
1. (d) Which the following is an inter-domain routing protocol?
- (i) RIP
- (ii) OSPF
- (iii) BGP
- (iv) Both (a) & (b)Answer: (iii) BGP
1. (e) Phase transition for each bit is used in
- (i) NRZ encoding
- (ii) Manchester encoding
- (iii) Carrier modulation
- (iv) Amplitude modulationAnswer: (ii) Manchester encoding
1. (f) Which one of the following is a valid host for network 192.168.4.32/28? (Assuming /28, as /68 in the source is a typo)
- (i) 192.168.4.39
- (ii) 192.168.4.50
- (iii) 192.168.4.47
- (iv) 192.168.4.31Answer: (i) 192.168.4.39 (The network range is 192.168.4.32 to 192.168.4.47. Hosts are .33 to .46)
1. (g) UDP is
- (i) connection oriented
- (ii) connection less
- (iii) both (a) and (b)
- (iv) none of these.Answer: (ii) connection less
1. (h) The protocol that maps a physical (MAC) address to the corresponding logical address is
- (i) ARP
- (ii) RARP
- (iii) ICMP
- (iv) IMAP4Answer: (ii) RARP (Reverse Address Resolution Protocol)
1. (i) Process to Process delivery is the function of ___ layer.
- (i) Transport
- (ii) Network
- (iii) Physical
- (iv) none of theseAnswer: (i) Transport
1. (j) Which channel access method is used in IEEE 802.5 networks?
- (i) CSMA/CD
- (ii) Token bus
- (iii) Token ring
- (iv) All of theseAnswer: (iii) Token ring
2022 (B.Tech 6th Sem)
1. (a) A proxy server is used as the computer
- (i) with external access
- (ii) acting as a backup
- (iii) performing file handling
- (iv) accessing user permissionsAnswer: (i) with external access
1. (b) The term ‘WAN’ stands for
- (i) Wide Area Net
- (ii) Wide Access Network
- (iii) Wide Area Network
- (iv) Wide Access NetAnswer: (iii) Wide Area Network
1. (c) Which layer of the TCP/IP stack corresponds to the OSI model transport layer?
- (i) Host-to-host
- (ii) Application
- (iii) Internet
- (iv) Network accessAnswer: (i) Host-to-host
1. (d) What is the maximum header size of an IP packet?
- (i) 32 bytes
- (ii) 64 bytes
- (iii) 30 bytes
- (iv) 60 bytesAnswer: (iv) 60 bytes (15 * 4-byte words)
1. (e) The address which is used to identify a process on a host is
- (i) physical address
- (ii) port address
- (iii) logical address
- (iv) specific addressAnswer: (ii) port address
1. (f) Which sublayer of the information link layer performs circuit functions that depend on the kind of medium?
- (i) Media access control sublayer
- (ii) Logical link control sublayer
- (ii) Network interface control sublayer
- (iv) Both (i) and (ii)Answer: (i) Media access control sublayer
1. (g) Transport layer protocol deals with
- (i) application-to-application communication
- (ii) node-to-node communication
- (iii) the process-to-process communication
- (iv) Both (i) and (ii)Answer: (iii) the process-to-process communication
1. (h) FTP server
- (i) maintains state information
- (ii) is stateless
- (ii) has single TCP connection for a file transfer
- (iv) has UDP connection for file transferAnswer: (i) maintains state information
1. (i) Which of the following is the multiple access protocol for channel access control?
- (i) CSMA/CD
- (ii) CSMA/CA
- (iii) Both CSMA/CD and CSMA/CA
- (iv) HDLCAnswer: (iii) Both CSMA/CD and CSMA/CA
1. (j) Physical layer provides
- (i) mechanical specifications of electrical connectors and cables
- (ii) electrical specification of transmission line signal level
- (ii) specification for IR over optical fiber
- (iv) All of the aboveAnswer: (iv) All of the above
2019 (B.Tech 5th Sem)
1. (a) This, layer is an addition to OSI model when compared with TCP IP model:
- (i) Application layer
- (ii) Presentation layer
- (iii) Session layer
- (iv) Both session layer and presentation layerAnswer: (iv) Both session layer and presentation layer
1. (b) Application layer is implemented on
- (i) end systems
- (ii) NIC
- (iii) ethernet
- (iv) routeAnswer: (i) end systems
1. (c) Which of the following is not applicable for IP?
- (i) Error reporting
- (ii) Handle addressing conventions
- (iii) Datagram format
- (w) Packet handling conventionsAnswer: (i) Error reporting
1. (d) Which one of the following is not a function of network layer?
- (i) Routing
- (ii) Inter-networking
- (iii) Congestion control
- ) None of the aboveAnswer: (iii) Congestion control
1. (e) For a 10 Mbps Ethernet link, if the length of the packet is 32 bits, the transmission delay is (in milliseconds)
- (i) 3.2
- (ii) 32
- (iii) 0-32
- (iv) None of the aboveAnswer: (iv) None of the above (Calculation: 32 bits / 10,000,000 bps = 0.0032 ms)
1. (f) Transmission delay does not depend on
- (i) packet length
- (ii) distance between the routers
- (iii) transmission rate
- (iv) None of the aboveAnswer: (ii) distance between the routers
1. (g) In TCP, sending and receiving data is done as
- (i) stream of bytes
- (ii) sequence of characters
- (iii) lines of data
- (iv) packetsAnswer: (i) stream of bytes
1. (h) Suppose a TCP connection is transferring a file of 1000 bytes. The first byte is numbered 10001. What is the sequence number of the segment if all data is sent in only one segment?
- (i) 10000
- (ii) 10001
- (ii) 12001
- ( ) 11001Answer: (ii) 10001
1. (i) The protocol on which DNS application run is
- (i) Telnet
- (ii) UDP
- (iii) HTTP
- (iv) None of the aboveAnswer: (ii) UDP (primarily)
1. (j) ___ allows you to connect and login to a remote computer.
- (i) Telnet
- (ii) FTP
- (ii) HTTP
- (iv) None of the aboveAnswer: (i) Telnet
2018 (B.Tech 5th Sem)
1. (a) The IETF standard documents are called
- (i) RFC
- ( ) RCF
- (ii) ID
- (iv) None of the aboveAnswer: (i) RFC (Request for Comments)
1. (b) The ___ is the physical path over which a message travels.
- (i) path
- (ii) medium
- (iii) protocol
- (iv) routeAnswer: (ii) medium
1. (c) The structure or format of data is called
- (i) syntax
- (ii) semantics
- (iii) struct
- (iv) None of the aboveAnswer: (i) syntax
1. (d) Transport layer is implemented in
- (i) end system
- (ii) NIC
- (iii) ethernet
- (iv) None of the aboveAnswer: (i) end system
1. (e) The functionalities of presentation layer includes
- (i) data compression
- (ii) data encryption
- (iii) data description
- (iv) All of the aboveAnswer: (iv) All of the above
1. (f) Header of a frame generally contains
- (i) synchronization bytes
- (ii) addresses
- (iii) frame identifier
- (iv) All of the aboveAnswer: (iv) All of the above
1. (g) Which one of the following is the multiple access protocol for channel access control?
- (i) CSMA/CD
- (ii) CSMA/CA
- (ii) Both CSMA/CD and CSMA/CA
- (iv) None of the aboveAnswer: (iii) Both CSMA/CD and CSMA/CA
1. (h) User datagram protocol is called connectionless because
- (i) all UDP packets are treated independently by transport layer
- ( ) it sends data as a stream of related packets
- (iii) it is received in the same order as sent order
- (iv) None of the aboveAnswer: (i) all UDP packets are treated independently by transport layer
1. (i) Transport layer protocols deals with
- (i) application to application communication
- (ii) process to process communication
- (iii) node to node communication
- (iv) None of the aboveAnswer: (ii) process to process communication
1. (j) Which one of the following is not a function of network layer?
- (i) Routing
- (ii) Internetworking
- (iii) Congestion control
- (iv) None of the aboveAnswer: (iii) Congestion control
2016 (B.Tech 5th Sem)
1. (i) In the following pairs of OSI protocol layer/sub-layer and its functionality, the INCORRECT pair is:1
- (A) Network layer and Routing2
- (B) Data Link Layer and Bit synchronization3
- (C) Transport layer and End-to-end process communication4
- (D) Medium Access Control sub-layer and Channel sha5ringAnswer: (B) Data Link Layer and Bit synchronization (Bit synchronization is Physical Layer)
1. (ii) Which of the following is NOT true with respect to a transparent bridge and a router?
- (A) Both bridge and router selectively forward data packets
- (B) A bridge uses IP addresses while a router uses MAC addresses
- (C) A bridge builds up its routing table by inspecting incoming packets
- (D) A router can connect between a LAN and WANAnswer: (B) A bridge uses IP addresses while a router uses MAC addresses (This is false; bridges use MAC, routers use IP.)
1. (iii) Which one of the following statements is FALSE?
- (A) TCP guarantees a minimum communication rate
- (B) TCP ensures in-order delivery
- (C) TCP reacts to congestion by reducing sender window size
- (D) TCP employs retransmission to compensate for packet lossAnswer: (A) TCP guarantees a minimum communication rate
1. (iv) Which one of the following statements is FALSE?
- (A) HTTP runs over TCP.
- (B) HTTP describes the structure of web pages.
- (C) HTTP allows information to be stored in a URL
- (D) HTTP can be used to test the validity of a hypertext link.Answer: (B) HTTP describes the structure of web pages. (HTML does this.)
1. (v) In a sliding window ARQ scheme, the transmitter’s window size is N and the receiver’s window size is M. The minimum number of distinct sequence numbers required to ensure correct operation of the ARQ scheme 6is
- (A) min (M,N)
- (B) max (M,N)
- (C) M+N
- (D) MNAnswer: (C) M+N
1. (vi) Which one of the following protocols is NOT used to resolve one form of address to another one?
- (A) DNS
- (B) ARP
- (C) DHCP
- (D) RARPAnswer: (C) DHCP (It assigns addresses, not resolves them)
1. (vii) Identify the correct sequence in which the following packets are transmitted…when a browser requests a webpage from a remote server, assuming that the host has just been restarted.
- (A) HTTP GET request, DNS query, TCP SYN
- (B) DNS query, HTTP GET request, TCP SYN
- (C) DNS query, TCP SYN, HTTP GET request
- (D) TCP SYN, DNS query, HTTP GET requestAnswer: (C) DNS query, TCP SYN, HTTP GET request
1. (ix) Which one of the following is TRUE interior Gateway routing protocols- Routing Information protocol(RIP) and Open Shortest Path First (OSPF)?
- (A) RIP uses distance vector routing and OSPF uses link state routing
- (B) OSPF uses distance vector routing and RIP uses link state routing
- (C) Both RIP and OSPF use link state routing
- (D) Both RIP and OSPF use distance vector routingAnswer: (A) RIP uses distance vector routing and OSPF uses link state routing
1. (x) In the slow start phase of the TCP congestion control algorithm, the size of the congestion window:
- (A) does not increase
- (B) increases linearly
- (C) increases quadratically
- (D) increases exponentiallyAnswer: (D) increases exponentially
Short-Answer Objective Questions
(Some exam papers used a short-answer format for their mandatory objective questions.)
2017 (B.Tech 5th Sem)
1. (a) Write any two functions of the session layer in OSI model.
Answer: 1. Dialog Control: Managing whose turn it is to transmit. 2. Synchronization: Adding checkpoints into a stream of data for recovery.
1. (b) What is Hamming code?
Answer: A set of error-correcting codes that can detect and correct single-bit errors.
1. (c) What is the significance of the twisting in twisted-pair cable?
Answer: Twisting reduces electromagnetic interference (EMI) and crosstalk between adjacent pairs of wires.
1. (d) What do you mean by piggybacking?
Answer: Combining an acknowledgment (ACK) for a received packet with an outgoing data packet in the reverse direction to improve efficiency.
1. (e) What is the purpose of the jam signal in CSMA/CD?
Answer: To ensure that all other nodes on the network segment are aware that a collision has occurred, so they stop transmitting.
1. (f) What are the advantages of dividing an Ethernet LAN with a bridge?
Answer: It divides the LAN into separate, smaller collision domains, which reduces the number of collisions and improves overall network throughput.
1. (g) What does the term ‘best effort’ mean in context with IP?
Answer: It means the Internet Protocol (IP) does not guarantee packet delivery, in-order arrival, or that the packet will be error-free.
1. (h) Why is there no need of CSMA/CD in a full-duplex switched Ethernet?
Answer: In a full-duplex switched environment, each node has a dedicated connection to the switch. Collisions cannot occur, so there is no need for Collision Detection.
1. (i) How does redundancy facilitate error detection?
Answer: By adding extra (redundant) bits (e.g., parity bits, CRC). The receiver can recalculate these bits and compare them to the received ones to detect errors.
2015 (B.Tech 5th Sem)
1. (a) Network layer of OSI model does not establish any relationship among different packets of same message. (Write True or False)
Answer: True.
1. (b) What is repeater?
Answer: A Physical Layer (Layer 1) device that regenerates a signal to extend the distance it can travel.
1. (c) What is baud rate?
Answer: The number of signal elements (symbols) transmitted per second.
1. (d) What is flooding in routing?
Answer: A routing technique where an incoming packet is sent out on every outgoing link except the one it arrived on.
1. (e) What is byte-oriented protocol?
Answer: A data link protocol that views data as a stream of 8-bit bytes (characters) and uses specific characters for framing.
1. (f) What is TCP?
Answer: Transmission Control Protocol. A connection-oriented, reliable, byte-stream protocol in the Transport Layer.
1. (g) What do you mean by connectionless service?
Answer: A network service (like UDP) where each packet (datagram) is handled independently and no prior connection setup is required.
1. (h) What is switch?
Answer: A Data Link Layer (Layer 2) device that connects network segments and uses MAC addresses to forward data only to the specific port of the intended recipient.
1. (i) What is the role of a bridge?
Answer: A Layer 2 device that connects two LAN segments and filters traffic between them based on MAC addresses, creating separate collision domains.
1. (j) List two protocols in channelization category.
Answer: FDMA (Frequency-Division Multiple Access) and TDMA (Time-Division Multiple Access).
2013 (B.Tech 5th Sem)
1. (b) What is CRC error detection scheme?
Answer: Cyclic Redundancy Check (CRC) is an error-detection method that treats the data as a polynomial and uses polynomial division with a generator polynomial to compute a checksum.
1. (c) Compare the advantages and disadvantages of bus and ring topologies.
Answer: Bus: Adv: Easy to install, cheap. Disadv: One break stops the network, difficult to troubleshoot. Ring: Adv: Orderly data transfer (no collisions). Disadv: One node failure can stop the network, complex.
1. (d) Describe the FDDI frame format.
Answer: Preamble, Start Delimiter, Frame Control, Destination Address, Source Address, Data (Payload), Frame Check Sequence (CRC), End Delimiter, Frame Status.
1. (e) How is Go Back n ARQ different from Selective Repeat ARQ?
Answer: In Go-Back-N (GBN), the receiver only accepts in-order packets. In Selective Repeat (SR), the receiver can buffer out-of-order packets and only requests retransmission of specific missing packets.
1. (f) What are two-army problem and a three-way handshake?
Answer: Two-Army Problem: A thought experiment proving it’s impossible to achieve guaranteed consensus over an unreliable channel. Three-Way Handshake: The (TCP) protocol (SYN, SYN-ACK, ACK) used to establish a reliable connection.
1. (i) What is World Wide Web?
Answer: An information system (service) running on the Internet that allows documents (web pages) to be connected to other documents using hypertext links.
1. (k)Explain in brief the topologies that are used for broadcast type of communication.
Answer: Bus topology: All data is sent on a single shared cable, and all nodes receive it. Star topology (with a Hub): A hub (Layer 1) receives data and broadcasts it out to all other ports.
We hope this compilation helps you in your exam preparation. What topics do you find the most challenging? Let us know in the comments!