Computer Networks

Question 1

What is computer network?

Answer 1

Collection of Interconnected computers and other devices to share data and resources.

Question 2

Advantages and disadvantages of computer networks?

Answer 2

Advantages
- Resource sharing
- Improved communication
- Central storage of data
- Reduces communication cost
- Data back-up

Disadvantages
- High cost of set up and maintenance
- Threat to data security

Question 3

What is meant by ‘reliability of data’?

Answer 3

It means backing up of data, i.e., data can be copied and stored on multiple devices.

Question 4

What was the first network that came into existence?

Answer 4

ARPANET, 1969
(Advanced Research Project Agency Network)

Question 5

Full form of ARPANET?

Answer 5

Advanced Research Project Agency Network

Question 6

Full form of NSFNET?

Answer 6

National Science Federation Network

Question 7

Define internet.

Answer 7

Internet is a network of networks.

Question 8

What is Interspace?

Answer 8

Software that allows multiple users in a client-server environment to communicate with each other by sending and receiving data.

It facilitates real-time exchange of data.

Question 9

How does internet work?

Answer 9

We use modem and dial a local number to connect to an ISP.

When connected to ISP computer becomes a part of its network.
The ISP then connects to a larger network and become a part of it.

The internet is network of networks.

Question 10

Full form?
ISP
POP
NAP

Answer 10

Internet Service Provider

Point of Presence

Network access points

Question 11

What is Gateway?
What is backbone?

Answer 11

Gateway is a device that connects dissimilar networks.

Backbone is a central interconnecting structure that connects one or more network like a tree trunk.

Question 12

What is the communication protocol used by internet?

Answer 12

TCP/IP
(Transmission Control Protocol)

TCP -responsible for dividing messages into packets on source computer and reassembling on the destination computer.

IP- responsible for handling the address of the destination computer

Question 13

What is TCP/IP?

Answer 13

(Transmission Control Protocol)

TCP -responsible for dividing messages into packets on source computer and reassembling on the destination computer.

IP- responsible for handling the address of the destination computer

Question 14

Define:
1. Nodes
2. Server

Answer 14

1. Workstations.
   Computers that are attached to a network.
2. Computer that facilitates sharing of data.

Question 15

Full form:
NIU
MAC

Answer 15

Network Interface Unit

Media Access Control

Question 16

What is NIU? Second name?

Answer 16

Network Interface Unit.
Helps establishing communication between server and client.

It’s also called network adapter, NI Controller

Question 17

What is MAC address?
What is IP Adress?

Answer 17

Memory Access Control.
- identifier for NIC, network address, 12 digit hexadec

IP
- Every device connected on a TCP/IP has a identifying no. given by ISP

Question 18

Components of data communication?

Answer 18

Sender
Reciever
Message
Transmission Medium
Protocol

Question 19

Analog vs Digital transmission

Answer 19

Analog= broadband transmission
• it’s a radio frequency signal
• telephone network use this type
• requires modem

digital= baseband transmission
• no special device for transmission
• signal is group of discrete electrical units
• it’s rapid

Question 20

Broadband vs Baseband transmission

Answer 20

Analog= broadband transmission
• it’s a radio frequency signal
• telephone network use this type
• requires modem

digital= baseband transmission
• no special device for transmission
• signal is group of discrete electrical units
• it’s rapid

Question 21

Parallel vs Serial communication

Answer 21

Parallel
- data transmitted through multiple wires
- each wire carry a bit

Serial
- bits are sent one after one along the wire

Question 22

Synchronous and asynchronous transmission

Answer 22

Sync
- sender firstvsends control characters to reciever and then sends actual data
- there’s no space between data
-faster
-costly, complex setup
-efficient for large amounts of data

Async
- data preceded and succeeded by a start bit and stop bit respectively.
- hardware simple cheap
- slow

Question 23

Circuit switching
Packet switching
Message switching

Answer 23

Circuit
- connection oriented service
-theres a dedicated link between sender and reciever
- no other call can be made even if it’s idle

Packet
- connectionless service
-data fragmented into small packets
- data received in sequence

Message
- store and forward switching technique
- no direct connection between sender and reciever

Question 24

Modem?

Answer 24

Modulator DEModulator

Enable computer to transmit data over telephone lines.
Device used to convert digital signal into analogue and vice versa.

Question 25

RJ-45?

Answer 25

Registered Jack-45

• used for connecting ETHERNET and LANs
• eight wire connector

Question 26

Hub
Switch
Bridge
Gateway

Answer 26

Hub shares bandwidth with all attached devices. Used to connect two comp with e/o.

Switch transmits data to comps in LAN

Bridge links two segments of original network together.

Gateway connects dissimilar networks.

Question 27

Repeater
Router

Answer 27

Repeater amplifies a signal.

Router helps forwarding data packets from one machine to another using the shortest path.

Question 28

TCP
IP
FTP
PPP
SMTP
POP3
TELNET
HTTP
HTTPs

Answer 28

(c) FTP (File Transfer Protocol)

(d) PPP (Point-to-Point Protocol)

(f) POP3 (Post Office Protocol 3)

(h) HTTP (Hyper Text Transfer Protocol)

(e) SMTP (Simple Mail Transfer Protocol)

(g) TELNET (Remote Login)

(i) HTTPs (Hyper Text Transfer Protocol Secure)

TCP (Transmission Control Protocol

Question 29

IRC
VoIP
H.323
SIP
HTML
XML
URL
DNR

Answer 29

Domain Name Resolution
- comp finds IP of a domain

Uniform Resource Locator

Extensible Markup Language

SIP
(Session Initial Protocol)

VoIP
Voice over Internet protocol

HTTPs
s is Secure

Question 30

Unguided media:

Answer 30

Microwave
Radio wave
Satellite link
Infra-red

Question 31

Coaxial cable:

Answer 31

Insulated copper
Surrounding braided metal shield
Covered by plastic jacket

Good shield against noise and crosstalk