CHAPTER-1-INTRODUCTION TO NETWORKS & NETWORK

MODELS

Short one mark and two marks question with answer

1. What is data communication?
Data communication is the process of transmitting data between two or more devices using a transmission
medium.
2. List components of data communication.
o Message
o Sender
o Receiver
o Transmission medium
o Protocol
3. What is network?
A network is a collection of connected devices that can communicate and share resources.
4. Define the term computer network.
A computer network is a system of interconnected computers that communicate with each other and share
resources like files, printers, and internet.
5. Define LAN.
LAN (Local Area Network) is a network that connects computers in a limited area like a home, office, or
building.
6. What is WAN?
WAN (Wide Area Network) is a network that covers a large geographical area, such as a country or
continent.
7. List design issues of the layer.
o Addressing
o Error control
o Flow control
o Routing
o Security
o Interoperability
8. Give function of network software.
Network software manages network communication, controls data flow, ensures security, and enables
resource sharing.
9. Define switching.
Switching is the method of directing data from the source to the destination through intermediate network
devices.
10. What is protocol?
A protocol is a set of rules that define how data is transmitted and received over a network.
11. Explain purpose of reference model.
The purpose of a reference model is to standardize network communication and guide the design of
network systems for compatibility.
12. Define the term internet.
The internet is a global network connecting millions of computers using the TCP/IP protocol.
13. List layers of OSI model.

 Physical
 Data Link
 Network
 Transport
 Session
 Presentation
 Application
14. Define MAN.
MAN (Metropolitan Area Network) is a network that covers a city or a large campus.
15. What is topology?
Topology refers to the arrangement of devices and cables in a network.
16. What is meant by data representation?
Data representation means displaying or encoding data in formats like text, numbers, audio, and video.
17. List layers of TCP/IP model.

 Application
 Transport
 Internet
 Network Access (Link layer)

18. Which methods are used for accessing Internet?

 Dial-up
 DSL
 Cable
 Fiber optic
 Satellite
 Mobile data (3G, 4G, 5G)

19. State any two characteristics of data communication.

 Accuracy
 Timeliness

20. What is network hardware?

Network hardware includes physical devices like routers, switches, hubs, and network cards used to build
and manage networks.
21. List network devices for TCP/IP model.

 Network Interface Card (NIC)

 Switch
 Router
 Hub
 Modem

22. What are the types of computer network?

 LAN (Local Area Network)

 WAN (Wide Area Network)
 MAN (Metropolitan Area Network)
 PAN (Personal Area Network)
 CAN (Campus Area Network)
 CHAPTER-2-LOWER LAYER
1. Lower layers in OSI model:
o Physical Layer
o Data Link Layer
o Network Layer
2. What is bandwidth?
o Bandwidth is the maximum rate at which data can be transferred over a network channel, usually
measured in bits per second (bps).
3. Define the term latency (delay):
o Latency is the time it takes for a data packet to travel from the source to the destination across a
network.
4. What is throughput?
o Throughput is the actual amount of data successfully transmitted over a network in a given time
period.
5. Define the term framing:
o Framing is the process of dividing a data stream into manageable units called frames for easier
transmission and error control at the data link layer.
6. What is jitter?
o Jitter is the variation in packet arrival times, often causing disruption in real-time communications
like video or voice.
7. List design issues of data link layer:
o Framing
o Error Control
o Flow Control
o Addressing
o Access Control
8. What is a frame?
o A frame is a data packet at the data link layer, containing the payload along with headers and
trailers for addressing and error checking.
9. List services of data link layer:
o Framing
o Physical addressing
o Error detection and correction
o Flow control
o Access control
10. What is flow control?

 Flow control is a mechanism to prevent the sender from overwhelming the receiver with too much data
too quickly.

11. Define congestion:

Congestion occurs when the demand for network resources exceeds the available capacity, causing packet loss
and delays.

12. List various framing methods:

 Character Count
 Flag Bytes with Byte Stuffing
 Starting and Ending Flags with Bit Stuffing
 Physical Layer Coding Violations

13. What is meant by channel allocation?

Channel allocation is the method used to assign communication channels to multiple users or devices in a
network.
14. What is ALOHA?
ALOHA is a simple communication protocol where users send data whenever they have data to send; collisions
are handled by retransmission after a random delay.

15. What is CSMA?

Carrier Sense Multiple Access (CSMA) is a protocol where a device listens to the channel before transmitting to
avoid collisions.

16. What is CSMA/CA?

CSMA with Collision Avoidance (CSMA/CA) tries to avoid collisions by using acknowledgments and waiting
periods before sending data (used in wireless networks).

17. What is CSMA/CD?

CSMA with Collision Detection (CSMA/CD) detects collisions during transmission and stops, waits for a
random time, then retries (used in wired Ethernet).

18. Define polling:

Polling is a method where a central controller asks each device in turn if it has data to send, avoiding collisions.

19. What is meant by channelization?

Channelization is the process of dividing a communication medium into separate channels for simultaneous
transmissions.

20. What is TDMA and FDMA?

 TDMA (Time Division Multiple Access): Divides time into slots assigned to users.
 FDMA (Frequency Division Multiple Access): Divides bandwidth into frequency bands assigned to
users.

21. Define switching:

Switching is the process of directing data from one device to another through a network.

22. List types of switching:

 Circuit Switching
 Packet Switching
 Message Switching

23. Give approaches for packet switching:

 Datagram Packet Switching

 Virtual Circuit Packet Switching

24. Define the term wired LANs:

Wired LANs are local area networks that use physical cables (like Ethernet) to connect devices.

25. What is Ethernet?

Ethernet is a widely used LAN technology that defines wiring and signaling standards for data transmission.

26. What is wireless LAN?

A wireless LAN (WLAN) is a local area network that uses radio waves instead of cables to connect devices.

27. List components for IEEE 802.11 architecture:

 Station (STA)
 Access Point (AP)
 Basic Service Set (BSS)
  Extended Service Set (ESS)
 Distribution System (DS)

28. What is Bluetooth?

Bluetooth is a short-range wireless technology used for exchanging data between devices over short distances.

29. List components for Bluetooth architecture:

 Master
 Slave
 Piconet
 Scatternet

Apply bit stuffing on the pattern: 01001111111101111110.

30. List any two channelization protocols.

Two common channelization protocols are:

1. FDMA (Frequency Division Multiple Access)

2. TDMA (Time Division Multiple Access)

CHAPTER-3 NETWORK LAYER

1. What are the services provided by the network layer?

 Routing of packets
 Logical addressing
 Packet forwarding
 Fragmentation and reassembly
 Congestion control

2. List functions of the network layer:

 Addressing
 Routing
 Packet forwarding
 Fragmentation
 Inter-networking

3. What is flow and error control?

 Flow control manages data transmission speed between sender and receiver.
 Error control ensures data is delivered accurately and retransmits corrupted packets.

4. Define congestion. When it occurs:

Congestion happens when too many packets are present in a network, leading to delays and packet loss. It occurs
when demand exceeds network capacity.

5. List types of congestion control mechanisms:

 Open-loop control (preventive)

 Closed-loop control (reactive)
 Admission control
 Traffic shaping
  Load shedding

6. What is an IP address?
An IP address is a unique identifier assigned to each device on a network for communication.

7. List classes for classful IP addressing:

 Class A
 Class B
 Class C
 Class D (Multicast)
 Class E (Experimental)

8. Define masking:
Masking uses a subnet mask to extract the network portion of an IP address.

9. What is meant by subnetting?

Subnetting is dividing a large network into smaller, manageable sub-networks.

10. Define supernetting:

Supernetting combines multiple networks into a larger one, reducing routing table entries.

11. What is meant by classless addressing?

Classless addressing (CIDR) removes the fixed class boundaries and allows variable-length subnet masking
(VLSM).

12. What is NAT?

Network Address Translation (NAT) translates private IP addresses to a public IP address to enable internet
access.

13. List network layer protocols:

 IP (IPv4 and IPv6)

 ICMP
 IGMP
 ARP (works with network layer)
 RIP, OSPF, BGP (routing protocols)

14. What is fragmentation?

Fragmentation is breaking a large packet into smaller ones to fit the maximum transmission unit (MTU) of the
network.

15. What is Mobile IP?

Mobile IP allows mobile devices to move between networks while maintaining a permanent IP address.

16. List three phases of Mobile IP:

 Agent Discovery
 Registration
 Tunneling

17. What is IPv6?

IPv6 is the next-generation Internet Protocol with a 128-bit address space, replacing IPv4.

18. List address types for IPv6:

 Unicast
  Multicast
 Anycast

19. What is an extension header?

Extension headers in IPv6 carry optional internet-layer information used for routing, fragmentation, or security.

20. Define routing:

Routing is the process of selecting a path for traffic in a network, from source to destination.

21. Role of routing algorithm in routing:

Routing algorithms determine the best path for data packets to travel from source to destination through a
network. They make decisions based on metrics like hop count, bandwidth, delay, and congestion.

22. List various routing algorithms:

 Distance Vector Routing

 Link State Routing
 Path Vector Routing
 Flooding
 Hierarchical Routing
 Adaptive (Dynamic) Routing
 Static Routing

CHAPTER-4 - Transport Layer

1. List functions of the transport layer:

 Process-to-process communication
 Segmentation and reassembly
 Flow control
 Error control
 Connection management
 Congestion control

2. What is the port number?

A port number is a 16-bit identifier used to specify a particular process or service on a device.

3. What is a socket address?

A socket address is a combination of an IP address and a port number that uniquely identifies a communication
endpoint.

4. Define pulling:
Pulling (or polling in some contexts) is when a client repeatedly checks or requests data from a server.

5. What is a buffer?
A buffer is a temporary storage area used to hold data while it's being transferred between two locations or
processes.

6. Give role of sequence number:

A sequence number ensures data is delivered in the correct order and helps in detecting missing or duplicate
segments.

7. Define congestion:
Congestion in the transport layer occurs when too much data is sent too quickly, overwhelming the network
resources and causing packet loss or delays.
8. List transport layer protocols:

 TCP (Transmission Control Protocol)

 UDP (User Datagram Protocol)
 SCTP (Stream Control Transmission Protocol)

9. UDP is connectionless protocol. State true or false:

True. UDP is a connectionless, unreliable protocol.

10. List UDP services:

 Process-to-process communication
 Low overhead data transfer
 Multiplexing and demultiplexing
 Suitable for real-time applications

11. What is TCP?

TCP (Transmission Control Protocol) is a connection-oriented, reliable transport layer protocol that ensures
ordered, error-checked delivery of data.

12. Which services are provided by TCP?

 Reliable data transfer

 Connection establishment and termination
 Flow control
 Error detection and correction
 Congestion control
 Ordered delivery