Computer Network Viva Questions 2025

1. Define a network.
   A network is a collection of networks joined together by physical media linkages. Recursively, a network is any physical link connecting two or more nodes or any two or more networks connected by one or more nodes.
2. How do links work?
   Two or more computers connected directly to one another via a physical media, such as a coaxial cable or optical fibre, can perform work at the lowest level. A link is an example of a physical medium.
3. Describe a Node.
   A network can be made up of two or more computers that are physically linked together, such as by coaxial cable or optical fibre. Such physical media is known as a link, and the computer that connects to it is referred to as a node.
4. What is a router or gateway?
   A node linked to two or more networks is referred to as a gateway or router. In most cases, it transmits the message from one network to another.
5. Describe the point-to-point link.
   We refer to physical connections as point-to-point links if they can only connect two nodes.
6. What is multiple access, exactly?
   If two or more nodes share the physical links, it is referred to as multiple accesses.
7. What benefits do distributed processing systems offer?
   Distributed processing systems offer various benefits, including distributed databases, collaborative processing, encapsulation or security, quicker problem solution, and security through redundancy.
8. What standards must a network meet to be effective and efficient?
   Reliability:

The amount of time it takes a link to recover from a failure, how often failures occur, and how robust the network is are all indicators of how reliable a system is.

Security:

Security concerns include guarding data from viruses and illegal access.

Performance:

A network’s performance can be evaluated in a number of ways, including through metrics like reaction time and transmit time.

9. What are the names of the variables that impact the performance of the network?
   Hardware, software, users, and various transmission mediums are all factors.
10. Talk about the elements that affect the network’s dependability.
    There are mainly two elements that affect the network’s dependability:

Frequency of failures;
Network recovery time after a failure.

11. What are the factors that affect the security of the network?
    There are several factors that affect network security, including viruses, unauthorized access, and many more.
12. What is the protocol?
    A protocol is a collection of guidelines that governs all facets of information communication.
13. What is the essential component of protocol?
    Key components of the protocol are:

Semantics:

It speaks of the significance of each bit in a segment.

The format and structure of the data, or the manner in which they are presented, make up a protocol’s syntax.

Timing:

It has the following two qualities:

When should the information we send
How quickly can data be sent?
14 Discuss the key design issues of a computer network.
There are various key design issues of a computer network, including:

Support for common services
Cost-effective resource sharing
Performance
Connectivity

15. What are latency and bandwidth?
    Latency and bandwidth are used to gauge the network’s performance. The number of beads that may be transmitted through the network in a specific amount of time is referred to as the network’s bandwidth. In contrast, latency describes the length of time it takes a message to transit over a network in terms of bits.
16. Talk about routing.
    The act of methodically forwarding a message to a destination node depending on its address is known as routing in a network.
17. What is a peer-to-peer process?
    Each process that communicates between machines at a specific network layer is known as a peer-to-peer process.
18. What is the congested switch?
    A switch may receive packets quicker than a card link that can hold them and store them in memory for a longer amount of time. If this occurs, the switch may eventually run out of buffer space, forcing some packets from it to be lost in a particular state. The situation of the network is referred to as the “congested condition of the network”.
19. Address the network’s semantic gap.
    Understanding the requirement applications and being aware of the technological constraints might help to define a useful channel. Therefore, the gap between application characteristics and the underlying technology can be described as the semantic gap in the network.
20. How long is the round trip?
    The Round-trip time is the amount of time it takes to send a message from one end of a network to the other and vice versa.
21. Talk about broadcasting, unicasting, and multicasting.
    Multicasting is a method by which the message is sent to some subset of other nodes.

Unicasting is a method by which the message is sent from a source to a single destination node.

Finally, broadcasting is a method by which the message is sent to all the nodes in the network.

22. Talk about multiplexing.
    Multiplexing is the process through which numerous signals are sent simultaneously over a single data channel.
23. Go over the different types of multiplexing.
    There are several types of multiplexing, including:

A. Time division multiplexing

Synchronous TDM
Asynchronous TDM or statistical TDM
B. Frequency division multiplexing

C. Wave division multiplexing

24. Talk about FDM.
    FDM is an analogue method that can be used when a link’s bandwidth is greater than the total bandwidth of the signals to be transferred.
25. How does WDM work?
    This method is comparable to FDM. Additionally, multiplexing and demultiplexing include the transmission of light signals across fibre optic channels.
26. What is TDM?
    TDM involves digital technology, and it can be used when the transmission medium’s data rate capacity exceeds the data rate needed by the transmitting and receiving devices.
27. Discuss Synchronous TDM.
    The multiplexer always assigns each device the exact same time slot in the synchronous time division multiplexing technique. The device might or might not have anything to communicate.
28. What are the OSI layers?
    There are several layers in the OSI Model, including,

Physical layer
Datalink layer
Network layer
Transport layer
Session layer
Presentation layer
Application layer

29. Which is the network-supported layer?
    Network-supported layers are,

Network layer
Physical layer
Datalink layer

30. Which is the user-supported layer?
    User-supported layers are,

Application layer
Presentation layer
Session layer

31. Which layer in the OSI stack connects the user-supported and network-supported layers?
    The user-supported layer and the network-supported layer are connected via the transport layer.
32. Talk about the issues with the physical layer.
    The physical layer coordinates the operations necessary for the transmission of a bit stream across a physical medium.

Representation of bits
physical characteristics of interfaces and media
data rate
bits synchronization
a line configuration
transmission mode
physical topology

33. Explain the functions of the network layer.
    Several functions of the network layer are,

The network layer is responsible for routing and logical addressing.
The network layer is in charge of delivering packets from source to destination, maybe through several networks.

34. Discuss the responsibilities of the data link layer.
    The data link layer transmits information to the physical layer. The data link layer is in charge of node-to-node distribution and conveys a raw facility to a dependable link.

physical addressing
flow control
framing
error control
access control