Class 10 Computer Science Solution
NETWORK AND TELE COMMUNICATION
a. Telecommunication is an art of communicating at a distance. The process of transferring data or information between computers is called data communication.
b. The basic elements of a communication system are :
i) A sender, which creates the message to be transferred.
ii) A medium which carries the message.
iii) A receiver which receives the message.
c. The system in which the data and information are transferred from one computer to another computer.
d. A computer network is a logical or physical interconnection between two or more computers such that they could communicate with each other.
e. Since a network allows sharing of hardware and software, it saves a considerable amount of money which would otherwise be spent on buying separate hardware and software for each computer. Thus, computer network reduces the cost of operation in offices.
f. The components of computer are as follows:
i. Server = A computer that provides the facilities of sharing the data, software, and hardware resources on the network is known as server.
ii. Workstation = Workstation refers to the computers that are attached to a network and use the resources of the network.
iii. Network Interface Card = Network adaptor is the interface that is used for connecting computers in networks. It is commonly known as Network Interface Card (NIC).
iv. Transmission Media = The communication channel provides the physical path through which data, information flow on a network.
g. Server is a computer or computer program that manages access to a centralized resource or service in a network.
Workstation is a computer intended for individual use that is faster and more capable than a personal computer. It is a computer dedicated to a user or group of users engaged in business or professional work.
h. The differences between dedicated server and non-dedicated server are as follows:
Dedicated Server means the server will only do what the user want it to do. The user has all of the computer resources at command.
A non-dedicated server is where the resources are shared between multiple users.
A dedicated server is a server shoes only job is to help workstation access data, software and hardware.
A non-dedicated server acts as a server as well as a workstation.
For example = If you are referring to a game server then dedicated is when your computer just runs the server.
For example = If you are referring to a game server then non-dedicated is when you are the server and you play.
i. A transmission media refers to any form of media that is primarily used for the transfer of signals. They are the physical pathways that connect computers, other devices and people on the network.
j. The bounded transmission media used on the network are as follows:
i. Twisted pair
ii. co-axial Cable
iii. Fiber optic cable
k. The importance of modem are as follows:
i. They allow higher speeds of transmission on a given analog line.
ii. They reduce the effects of noise and distortion.
l. The different types of computer network on the base of range are as follows:
i. Local Area Network (LAN)
ii. Metropolitan Area Network (MAN)
iii. Wide Area Network (WAN)
m. Local Area Network
A Local Area Network (LAN) is a network of computers that are relatively near to each other and are connected in a war that enables them to communicate by a cable and a small wireless device. A LAN consists of just two or three computers to exchange data or share resources or it can include hundreds of computers of different kinds.
n. Metropolitan Area Network
Metropolitan Area Networks (MANs) are large computers networks spread over a city or neighboring cities. A MAN can have a group of many LANs. Especially, big companies, banks, offices etc. have their branches or sub offices in a city or in neighboring cities. They use MAN to connect with their branches or sub offices for communicating data and information. The communication media in MANs may be optical fiber or unbounded communication media like microwave system, infrared system, radiowave to link their branches and sub offices.
o. Wide Area Network
Wide Area Network is a telecommunications network usually used for connecting computers that spans a wide geographical area. WANs can be used to connect cities, states or even computers. Typically, it will employ communication circuits such as long distance telephone wires, microwaves and satellites. WANs are often used by larger corporations or organizations to facilitate the exchange of data. The world's most popular WAN is the Internet.
p. The differences between LAN and WAN are as follows:
q. It is a type of network in which each computer in a network is either a client or a server. It is an arrangement where some programs, files or other resources located on one computer called the server but are available to other systems on the network, called clients.
r. Peer to peer network is a type of decentralized and distributed network architecture in which individual nodes in the network acts as both suppliers and consumers of resources in contrast to centralized client server model.
FTP = File Transfer Protocol
SMTP = Simple Mail Transfer Protocol
TCP/IP = Transmission Control Protocol/ Internet Protocol
ISP = Internet Service Provider
POP = Post Office Protocol
UTP = Unshielded Twisted Pair
STP = Shielded Twisted Pair
NetBEUI = Net Bios Enhancer User Interface
DARPA = Defence Advanced Research Projects Agency
HTTP = Hyper Text Transfer Protocol
3. A computer network topology is the physical communication scheme used by connected devices. It is the way computer systems or network equipment are connected to each other.
The three network topologies are as follows:
i. Ring Topology
ii. Bus Topology
iii. Star Topology
4. A bus topology is a network topology in which nodes are connected in a daisy chain by a linear sequence of buses. It is an arrangement of computers on a local area network in which each computer is connected to a central cable through which data is channeled.
5. The advantages of bus topology are as follows:
i. It is easy to set up and extend bus network.
ii. Cable length required for this topology is the least compared to other networks.
iii. Bus topology costs very less.
iv. It is mostly used in small networks. It is good for LAN.
6. The disadvantages of bus topology are as follows:
i. It is not suitable for networks with heavy traffics.
ii. It is difficult to detect and troubleshoot fault at individual station.
iii. There is limit on central cable length and number of nodes that can be connected.
iv. Security is very lows because the entire computer receives the sent signals from the source.
7. Ring topology is a network topology in which each node connects to exactly two other nodes, forming a single continuous pathway for signals through each node – a ring. Data travel from node to node with each node along the way handling every packet.
8. The advantages and disadvantages of ring topology are as follows:
i. Very orderly network where every device has access to the token and opportunity to transmit.
ii. Does not require central node to manage the connectivity between the computers.
iii. Point to point line configuration makes it easy to identify and isolate faults.
iv. Performs better than bus topology under heavy network load.
i. One malfunctioning workstation can create problems for the entire network.
ii. Moving, adding and changing the devices can affect the network.
iii. Communication delay is directly proportional to number of nodes in the network.
iv. Bandwidth is shared on all links between devices.
9. A hub is a hardware device that relays communication data. A hub sends data packets to all devices on a network, regardless of any MAC addresses contained in the data pocket.
10. Star topology is a network topology where each individual piece if network is attached to a central node. The attachment of these network pieces to the central component is visually represented in a dorm similar to a star.
11. The advantages and disadvantages of star topology are as follows:
i. As compared to bus topology, it gives far much better performance.
ii. Easy to connect new nodes or devices. In star topologynew nodes can be added easily without affecting rest of the network.
iii. Centralized management. It helps in monitoring the network.
iv. Failure of one node or link does not affect the rest of network. At the same time it is easy to detect and troubleshoot it.
i. Too much dependency on central devices. If it falls whole network goes down.
ii. The use of hub, router or a switch as central devices increases the overall cost of the network.
iii. Performance and as well number of nodes which can be added in such topology is depended in capacity of central devices.
12. A computer protocol is a system of digital rules for message exchange within or between computers. They are the formal descriptions of digital messages formats and rules. They are required to exchange messages in or between computing systems and are required in telecommunications.
Any four communication protocols are as follows:
i. Transmission Control Protocol/ Internet Protocol (TCP/IP)
ii. Post Office Protocol (POP)
iii. Net Bios Enhancer User Interface (NetBEUI)
iv. Internet Pack Exchange/ Sequential Packet Exchange (IPX/SPX)
13. Internet is a worldwide system of computer network. It is a network of networks in which users at any one computer can, if granted permission, get information from any other computer.
Any four services of internet are as follows:
i. Electronic Mail
ii. World Wide Web
iii. Electronic Fax
14. The task of HTTP is that it is used to communicate between Web client and servers. Its primary task is to move requests from clients to server and response vice versa.
15. The task of FTP is that it is used to copy files between two computers on the internet.
16. The facilities provided by the internet are as follows:
i. Electronic Mail (E-mail) = It is an electronic message sent from one computer to another.
ii. Telnet = Telnet allows internet users to access another computer linked to the internet.
iii. Usenet = Usenet is acting like a huge bulletin board with thousands of newsgroups and subgroups.
iv. World Wide Web (WWW) = Information can be accessed on the internet through the World Wide Web. Web is a system of organizing, linking and providing access to related internet files, resources and services.
It is the services of internet in which messages are sent from and received by the servers.
It is the services of the internet in which faxes are sent from and received by the servers.
The messages sent can be received in the email box.
The faxes sent are received through faxes.
It is an open, public space, a worldwide system of interconnected computer networks.
It is a private network within an organization that resembles the internet.
It is worldwide, publicly accessible series of computer networks.
It is password protected and is accessible to only the authorized persons.
b. Network Repeater
h. Network Interface Card
k. Local Area Network
l. File Transfer Protocol
n. Hyper Text Transfer Protocol
o. Star topology
p. Post Office Protocol
q. Peer To Peer Network
t. Fiber Optic Cable
u. Non Dedicated Server