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Computer Network

Knowing Communication and its typesNetwork Terminologies and media

Network DevicesNetwork Types and topologies

Network services

Objectives

1ComputerNetwork


Computer Network

Communication...............................................................Communication...............................................................Communication...............................................................Communication...............................................................Communication...............................................................arol and Michael communicate to each other in English, they both understand what oneis saying and what the meaning is. Sushma and Alisha talk in Nepali language

and both can communicate every matter very well in Nepali language. So both theabove examples talk about the word communication. Words and the language

(English, Nepali, etc) play a vital role in making people understanding each others ideas,views, opinions feelings, sentiments, etc.

The word communication means a medium of expressing and receiving information betweentwo or more people using certain standard of language. People in the past used to make acommunication using various sounds, lighting fires, playing drums, reflecting mirrors and even

using a messenger. It was very tedious, time consuming and difficult to send or receive exactinformation due to the lack of a proper standard of communication and medium.

Now science and technology have advanced so much that not only the local level of communication

have become easier, cheaper and advanced but also national and international level of communicationhas become cheaper, more reliable and trustworthy with the invention and usages of thesophisticated devices. Especially, with the development of microcomputers after 1980s, it hasgiven a brand new look to communication. Furthermore, the development in a computer, devices,

technology and network system, the trend of communication has become easier, comfortable,affordable, reliable, etc. One can make easy access to the vast resource of information; can keephimself/herself updated with the latest happening around the world within fractions of a minutesthat’s why the whole world has changed into a small village termed as “Globalization” or

“Global Village”.

Data Communication System.............Data Communication System.............Data Communication System.............Data Communication System.............Data Communication System.............Telecommunication is a system of transmission of sound, images, texts or data in the form ofelectronic signals. Data communication is the fastest growing field of telecommunication. It iscollection of hardware, software and other devices that assist in exchanging data, information

and voice between two or more devices through a wired or wireless medium (radio waves).

Types of Communication.............Types of Communication.............Types of Communication.............Types of Communication.............Types of Communication.............Communication can be categorized in two ways. They are: one way communication simplex andtwo ways communication (duplex). One way communication takes place in only one direction i.e.sending information such as newspaper, television, radio, etc whereas in two ways communication

both directions simultaneously take part in receiving the information and sending them such astelephone, internet chats, video conferencing, etc.

CCCCC

Data communication is the fastest growing field of telecommunication.


Computer Network

Communication In Computer.............Communication In Computer.............Communication In Computer.............Communication In Computer.............Communication In Computer.............Communication in computer is one of the mostly practiced jobs in any computerized system,institution, organization, etc. It becomes a necessity to divide a complete project to variousindividuals in an organization. The divided sub parts are complied together to make a complete

system after completion of assigned duties. So, working successfully in a group for an aim,sharing information with fellow people, reducing the cost of expenditure and making implementation ofsafety and secured communication should be established. This age is very busy time and all thepeople are hurry every moment. Everyone wants to do a lot of work perfectly and absolutely error

free in short span of time. So computers can be used for making that all happened. This is theimagination and efforts of man that has been effectively helping human beings in communication,sharing resources easily in a very short period of time. So the computers are used for establishingcommunication one to another computer through a network system. Computer network deals

with passing data, resources, sharing peripherals by the connection of cables, satellites etc. Thecomputer network has provided us a medium of communication by sending and receiving data toother person’s computer which is simply done by setting computer in networking.

Computer Network.............Computer Network.............Computer Network.............Computer Network.............Computer Network.............Interconnection of two or more than two computers by means of certain transmission medium (or

media) and logical set of rules to share information and resources is computer networking. Thetransmission medium (like coaxial cable, UTP cable etc.) provides physical path for the communicationbetween the computers in a network while the logical rules are the set of standards, which thosecomputers adopt to communicate with each other.

In other words, computer network is a system of computer communication that links together anumber of computers for transfer of information and instruction between the users of thecomputer.

1 Network between Computers

Switch

Computer 1 Computer 2

Computer network deals with passing data, resources, sharing peripherals by the connection ofcables, satellites etc.

TipThe first network access system called Ethernet was developed by Xerosin 1970s.


Computer Network

There are many advantages using networks, such as you can share resources stored in computerto any other computers, share printer, etc. within the network established. The more advantages

are listed below:

Advantages of Computer Network.............Advantages of Computer Network.............Advantages of Computer Network.............Advantages of Computer Network.............Advantages of Computer Network.............1. Provides easy access to resources of information and share them among connected computers.2. Provides access to network connected hardware devices like printers, hard disk, etc.3. Allows sharing of different software package.

4. Allows for the electronic transfer of text (chat, mailing etc.).5. Provides facility of quick updation from any computer in network and updated resources can

be utilized by all the computers in network.6. Decreases the cost of data transfer in comparison to the traditional way of transmission.

7. Allows easy and safe backup of information and resources.

Network Terminologies.............Network Terminologies.............Network Terminologies.............Network Terminologies.............Network Terminologies.............There are certain network terms that are important to be understood first.

1.1.1.1.1. Server.............Server.............Server.............Server.............Server.............A server is a computer that provides important devices, program that can be used by all users ofthe network in different workstations. A network server provides network services to a user

workstation on the network, which can range from sharing database and files, printers, commu-nications or other network resources. They can be dedicated to the task of providing networkservices. Such servers are called dedicated network servers. Otherwise, they may be callednon-dedicated servers.

Workstation

WorkstationWorkstation

Workstation

Server

2 Server

A network computer that shares its resources and responds to requests from other networkedcomputers is Server.


Computer Network

The network servers are of the following types:a. File ServerA file server is a special computer, which provides a form of auxiliary storage that can be used byanother computer on the network. In other words, it is a server that provides shared hard disk so

that the other user on different workstations can share the same hard disk.

b. Print Server:The print server is a special printer, which can receive data from other computer on the networkand prints it. It is a special printer that provides shared printer.

c. Communication Server:Communication server is that server which provides shared modems, through which the worksta-

tions can connect to the internet.

222... CCCllliiieeennnttt... ............A client computer is one, which accesses data and information from the server. If you are

accessing Internet facility from an Internet Service Provider (ISP), then your computer is the

client computer. In other words, the user computer that make request for services or data on the

network from the server is called a client computer.

333... WWWooorrrkkkssstttaaatttiiiooonnn... ............A workstation is a computer in a computer network, which accesses data and information fromthe main server. Some workstations are ‘dumb’ i.e. they don’t possess any processor and so theytake the help of the server while processing data. Such computers have only an input unit(keyboard), a CPU and a console (monitor). Some workstations are “intelligent’ having intel-ligent processing capabilities.

NNNeeetttwwwooorrrkkk CCCooommmmmmuuunnniiicccaaatttiiiooonnn MMMeeedddiiiaaa... ............Network communication media or transmission medium is a channel through which data or signals can be transmitted from one point to another. So network communication media pro-vides electronic pathways along which the signals are transferred. The signals are transferred through electromagnetic signals. It includes voice, radio waves, infrared light, power, ultraviolet rays, etc and transmission of such signals is done through cables, Fiber Optic Cable, vacuum air, etc. There are two types of communication media:

1. Bounded (Wired) media2. Unbounded (Wireless) media.

GP comes in different categories (Cat 1 to Cat 7 category 1 tocategory 7. Cat is the most popular category that uses Rj-45connection.

A network computer that utilizes the resources of other network computer is a client.


Computer Network

Bounded MediaBounded media is a medium that uses cables line through which data travel to a specified path.These cables media contain a conductor made of copper or silver wires through which electricity

or pulses of light flows. Some of the bounded media are: Twisted Pair Wire, Coaxial cable andFiber Optic Cable.

Unbounded MediaUnbounded transmission uses a transmission carrier to send data signals through the air insteadof cables. It does not use any sort of wires or cables to flow information in the network. Radio

frequency, infrared transmission and microwave transmission are common examples of unboundedtransmission media. The unbounded transmission media has some advantages over boundedmedia: the unbounded media is easier to install and reconfigure and they afford client machinesa lot of mobility.

Network Connecting Devices.............Network Connecting Devices.............Network Connecting Devices.............Network Connecting Devices.............Network Connecting Devices.............There are many network connecting devices that are used to connect one computer to another orone device to another for transmission of data or information.

1. Cables.............Cables are the main transmission medium in a network, especially in case of Local Area Network(LAN). There are different types of cables that are used for networking. Some of them are:

a. Twisted Pair Cable(RJ45)b. Co-axial Cablec. Fibre-Optic Cable

3 Network Cables

Twisted Pair Cable Fibre-Optic Cable

Co-axial Cable

Bandwidth is the capacity of carrying data by a media.


Computer Network

2. NIC Card (Network Interface Card)It is also called as Network Adapter. It is a computer circuit board that is installed in a computer,so that it can be connected to a network. Personal computer (PC) and workstation on a LANtypically contain a NIC card that provides a dedicated full time connection to a network.

4 NIC Card

3. HubsThey are connectivity devices that connects computer in a star topology. They contain multiple

openings (ports) for connecting to network components. A single cable is connected to the hubfrom the server and many segments of cables branch out from the hub to the other workstationsin a network.

5 16 Port Hub

4. BridgeIt is a device that passes data-packet between multiple network segments that use the samecommunication protocol (set of rules or standards which help to communicate with between two

or more than two computers). It passes one signal at a time. It is generally used for largeextended networks.

A device with multiple port that lets the network devices connect together is a Hub.


Computer Network

6 Bridge

5. RepeaterIt is a device that is used to interconnect the media segments of an extended network. Itessentially enables a series of cable segment to be treated as a single cable. If a cable is verylong, the signal weakens and becomes unrecognizable. It is also used to interconnect extended

networks.

7 Repeater

6. RouterIt is a device that acts like a bridge but provides more functionality. In moving data betweendifferent network segments, it examines the packet header (address) to determine the bestpath for the packet to travel. Router enables all users in a network to share single connection tothe Internet.

8 Router

Router connects multiple networks that use the same protocol.


Computer Network

7. ModemIt stands for Modulation Demodulation. It is a device that allows a computer to transmitinformation over a telephone line. It is connected with a computer and a telephone line. Whentransmitting data, it converts the digital signal into analog signal and transmits in over a tele-

phone line. When receiving data, it converts the analog signal into digital signal.

9 Modem

TTTyyypppeeesss ooofff NNNeeetttwwwooorrrkkksss... ............There are many types of computer networks, including: 1. LOCAL-AREA NETWORKS (LANS) : The computers are geographically close together (that

is, in the same building).

2. METROPOLITAN-AREA NETWORKS MANS): A data network designed for a town or city.3. WIDE-AREA NETWORKS (WANS) : The computers are farther apart and are connected by

telephone lines or radio waves.4. CAMPUS-AREA NETWORKS (CANS): The computers are within a limited geographic area,

such as a campus or military base.5. HOME-AREA NETWORKS (HANS): A network contained within a user’s home that connects

a person’s digital devices.

LLLooocccaaalll AAArrreeeaaa NNNeeetttwwwooorrrkkk (((LLLAAANNN)))... ............A Local Area Network (LAN) refers to a network of computers in a single room or inside a singlebuilding. LANs normally do not exceed a couple of kilometers in size and tend to use only one typeof transmission medium. LANs are mostly used by airlines, hotels, schools, banks etc.

The classification of network is done by depending upon geographical distribution, communicationmedia, device, data transfer rate, company’s size etc.

Internet is a global network of networks that runs on TCP/IP.


Computer Network

LANs are typically identified by the following properties• Multiple systems attached to shared medium

• High total bandwidth (~10’s Mbd)• Low delay• Low error rate• Broadcast/Multicast capability

• Limited geography (1-2 km)• Limited number of stations• Peer relationship between stations• Confined to private property

MMMeeetttrrrooopppooollliiitttaaannn AAArrreeeaaa NNNeeetttwwwooorrrkkk (((MMMAAANNN)))... ............A Metropolitan Area Network (MAN) is a network that is larger than a LAN. It is called metropolitan

since it normally covers the area of a city (a few tens to about hundred kilometers) that are

divided by mountains. Different hardware and transmission media are often used in MANs

because they must efficiently cover these distances. MANs generally take the help of satellite to

transmit information. It is used by communication media, business organization, airlines etc.

There are three important features, which discriminate MANs from LANs or WANs: 1. The

network size falls intermediate between LANs and WANs. A MAN typically covers an areaof between 5 and 50 km diameter. Many MANs cover an area the size of a city, although in

some cases MANs may be as small as a group of buildings or as large as the North of Scotland.2. A MAN (like a WAN) is not generally owned by a single organization. The MAN, its

communications links and equipment are generally owned by either a consortium of users orby a single network provider who sells the service to the users. This level of service providedto each user must therefore be negotiated with the MAN operator, and some performanceguarantees are normally specified.

3. A MAN often acts as a high speed network to allow sharing of regional resources (similar to a

large LAN). It is also frequently used to provide a shared connection to other networks using

a link to a WAN.

A Metropolitan Area Network (MAN) is a network that is larger than a LAN.

TCP/IP protocols are developed by Department of Defense, USA.It is often called as Internet Protocol. It is used to transferdigital data around the Internet.


Computer Network

A typical use of MANs to provide shared access to a wide area network is shown in the figurebelow:

10 Illustration of different Networks

Wide Area Network (WAN).............Wide Area Network (WAN).............Wide Area Network (WAN).............Wide Area Network (WAN).............Wide Area Network (WAN).............WANs are networks that span large geographical areas. Computers can connect to thesenetworks to use facilities in another city or country. For example, a person in Los Angeles canbrowse through the computerized archives of the Library of Congress in Washington, D.C. Thelargest WAN is the Internet, a global consortium of networks linked by common communication

programs and protocols (a set of established standards that enable computers to communicatewith each other). The Internet is a mammoth resource of data, programs, and utilities. Americancomputer scientist Vinton Cerf was largely responsible for creating the Internet in 1973 as part ofthe United States Department of Defense Advanced Research Projects Agency (DARPA). In 1984

the development of Internet technology was turned over to private, government, and scientificagencies. The World Wide Web, developed in the 1980s by British physicist Timothy Berners-Lee,is a system of information resources accessed primarily through the Internet. Users can obtain avariety of information in the form of text, graphics, sounds, or video. These data are extensively

cross-indexed, enabling users to browse (transfer their attention from one information site toanother) via buttons, highlighted text, or sophisticated searching software known as search en-gines.WANs use a variety of transmission technology such as telecommunication link, microwaves and

satellites. WAN is mostly used by big trading organization, telecommunication department, bighotels and airlines.Generally speaking, MAN and WAN are slower than LAN.In addition to these types, the following characteristics are also used to categorize different types

of networks:

Generally speaking, MAN and WAN are slower than LAN.


Computer Network

TopologyThe geometric arrangement of a computer system. Common topologies include a bus, star, andring.

ProtocolThe protocol defines a common set of rules and signals that computers on the network use tocommunicate. One of the most popular protocols for LANs is called Ethernet. Another popular LANprotocol for PCs is the IBM token-ring network.

ArchitectureNetworks can be broadly classified as using either a peer-to-peer or client/server architecture.

Computers on a network are sometimes called nodes. Computers and devices that allocateresources for a network are called servers.

NNNeeetttwwwooorrrkkk TTTooopppooolllooogggyyy... .............................................................The way computers are laid out in a network is called network topology. It defines the physicalstructure of the network. Some of the important LAN topologies are as follows:

iii... BBBuuusss tttooopppooolllooogggyyy... ............A physical bus topology network typically consists of computers arranged in a linear fashion. Ituses a linear cable to which the NIC (Network Interface Cards) cards of computers are attachedusing T-connectors. The linear cable is terminated at both ends to avoid signal reflection at theends of the cable.

Advantages• Ease of installation •

Ease of troubleshooting• Less cable required

The main disadvantage of Bus topologyis that when the fault arises at anypoint on the cable, entire networkstops functioning.

11 Bus Topology

Protocol is a set of rules that are followed by the sender and the reviver to make communicationpossible.

Some of the Protocols are TCP/IP, ARP (Address ResolutionProtocol), HTTP, FTP, SMTP, POP etc.


Computer Network

ii.ii.ii.ii.ii. Star topology.............Star topology.............Star topology.............Star topology.............Star topology.............Physical star topology uses a central device with drop cables extending in all directions. Eachnetworked device is connected via point-to point link to the central device called hub.

Advantages• Ease of installation

• Ease of reconfiguration• Ease of troubleshooting• Failure of one-drop cable causes

only the associated computer to

be disconnected from thenetwork while other machines inthe network work fine.

Disadvantages• Requires extra device (hub)

• Requires more cable than Bustopology.

12 StarTopology

iii. Ring topology.............iii. Ring topology.............iii. Ring topology.............iii. Ring topology.............iii. Ring topology.............As its name suggests, the physical ring is a circular topology where computers are arranged in aring structure, either in a physical or logical manner. In any case, each computer in the networkwaits for the token to transmit the message. Since each computer has to wait for its turn in thering, this is called Ring topology. This topology requires a device called MAU (Multi-station Access

Unit)

13 Ring TopologyAdvantages• Easy set and reconfiguration.• Equal access to all computers in the network

resources.

Disadvantages• Entire network may be affected in terms of

failure of cable or computer.• Difficult to detect errors.• Entire network is affected when devices are

added or removed.

In Star Topology a device called Hub or Switch is used as a central device that helps to transferdata to longer distance.


Computer Network

Network operating systems.............Network operating systems.............Network operating systems.............Network operating systems.............Network operating systems.............The operating system that works for a network system is called a network operating system.There are various networking operating system found in the market. The network operating

systems discussed here are client/server network operating systems.

Novell NetWare.............Novell NetWare.............Novell NetWare.............Novell NetWare.............Novell NetWare.............Novell NetWare is the oldest PC-based product in the network operating system category. NetWareis an intense and complex product. By contrast with other, newer network operating systems likeMicrosoft Windows NT, it is difficult and contentious. It is also not well suited to being an

application server or server that runs network service applications such as database or faxapplications and its system console is a command line similar to DOS or UNIX. However, for andprint services, it remains the fastest PC-based network operating system available.Novell’s proprietary network protocol is IPX/SPX (Internetworking Packet Exchange/Sequenced

Packet Exchange).

Windows NT.............Windows NT.............Windows NT.............Windows NT.............Windows NT.............Initially Windows NT version 3.1 was all in one product- there was initially little if anydifferentiation between version used for server and version used for workstation. By the timeMicrosoft released Windows NT 3.5 in 1995, Microsoft had created two different versions of the

operating system: Windows NT Workstation and Windows NT Server.The capability of connecting to all sorts of networks ranging from TCP/IP to NetWare to Windowsnetworking has been built into NT from the start. It is easier to learn because it uses the familiarWindows interface that simplifies administration. NT is admirably suitable from administration

point of view because of its point-and-click feature.From performance perspective, it is not as fast as NetWare or UNIX.

Linux.............Linux.............Linux.............Linux.............Linux.............Linux is a fully preemptive network operating system with a very rich interface. Themain difficulty with Linux is that it is not as user friendly as Windows NT Linux is far more

stable than any other network operating systems. Linux is relatively faster than Novell andWindows NT.Unlike other network operating systems, Linux comes with Source code. So, the users can modifythe code and make it best suited for his needs. Linux is best suited to networks in which an

experienced administrator is in charge.

Network Services (Client/Server Vs. Peer to Peer).............Network Services (Client/Server Vs. Peer to Peer).............Network Services (Client/Server Vs. Peer to Peer).............Network Services (Client/Server Vs. Peer to Peer).............Network Services (Client/Server Vs. Peer to Peer).............Network services are the capabilities that networked computers share. Following terms aregenerally used in network in connection with network services.

Linux is the most widely dominent NOS used in the big and known organization.


Computer Network

• Servers• Clients• Peers

These entities are differentiated by what they do in the network. Servers provide services• Clients request services from others (mainly servers)• Peers may do both simultaneously

Based on which services are used in a network, it can be classified as one of the following three

types:1. Centralized Networks2. Peer to Peer Networks3. Client/Server Networks

Centralized Network.............Centralized Network.............Centralized Network.............Centralized Network.............Centralized Network.............Centralized network is a network in which a central host computer controls all networkcommunication and performs data processing and storage on behalf of clients. They are basedon direct cabling from the terminals or terminals emulators to the mainframe and on processing

housed in the main central computer. Main (host) computers normally run the UNIX operatingsystem and can process multiple jobs in a very efficient manner. This network provides highperformance and centralized management but they are costly and not reliable since many largeand small corporations implement client server networks. This network is also called as host-

based networks.

Client/Server Networks.............Client/Server Networks.............Client/Server Networks.............Client/Server Networks.............Client/Server Networks.............In Client/Server networks, all computers have distinctly defined roles. One or more computers inthe network act as servers, which provide services to other computers, which are called clients.

This is the most widely used network model. Different types of servers provide different services.The most common services provided by different servers are as follows:

• File Services• Print Services

• Message Services• Application Services• Database Services

Peer-To-Peer Networks.............Peer-To-Peer Networks.............Peer-To-Peer Networks.............Peer-To-Peer Networks.............Peer-To-Peer Networks.............In Peer-To-Peer networks, all computers in the network are both clients and servers, i.e. allcomputers both request and provide network services. Networking using Windows 95, Windows98 are the most common examples of Peer-To-Peer networks.Centralized networks proved centralized management; Client/Server model providescentralized network services while Peer-To-Peer model offers distributed networkservices.

Centerlaized Computers Network is run with a powerful Network Operating System called UNIXand LINUX.


Computer Network

LabSession

Session 1

1. Familiarizing with the type of network available or used in your school lab/ accountdepartment, administration. Students can be taken in a place where various kinds of networks and topologies are used. The lab sessions’ conclusion should be: to diagnostic of type ofnetwork used the places they visit or see.

2. Students should be demonstrated the network components such as server, clients, NIC card,Modem, Hub, terminator, various cables, router, switch, etc devices so that they could knowmore closely to them.

3. Students should be asked to collect kinds of different cables used in networking, different

connectors Rj-45, etc.4. Students should do sharing, saving and accessing (data transfer) of resources from one

computer to another. Making the resources shared among the PCs in network. They shouldknow how a printer can be shared in network, how a modem is used in network, etc


Computer Network

Section A: Once more. ......Communication means a medium of expressing and receiving information between twoor more people using certain standard of language.Telecommunication is a system of transmission of sound, images, texts or data in the formof electronic signals.Interconnection of two or more than two computers either physically with cables or viavarious transmission media and logical rules to share information is called as computernetwork.A server is a computer that provides important devices, program that can be used by allusers of the network in different workstations. There are three types of servers:(a) File Server (b) Print Server (c) Communication ServerA client computer accesses data and information from the server.A workstation is a computer in a computer network, which accesses data and informationfrom the main server.Workstations are also called as Terminals, which are of two types:(a) Dumb Terminal (b) Intelligent Terminal

There are two types of communication media: (a) Bounded (Wired) media (b) Unbounded(wireless) media.A Local Area Network (LAN) refers to a network of computers in a single room or inside asingle building.A Metropolitan Area Network (MAN) is a network that is larger than a LAN and is usually anetwork of computers between different metropolicies.A widely dispersed system of computer connection without cable connection is called asWide Area Network (WAN). It generally covers network between countries.The physical layout or structure of network in a Local Area Network (LAN) is called atopology. Typically there are four types of LAN topologies.A Network Interface Card (NIC card) is a computer circuit board that is installed in acomputer, so that it can be connected to a network.A Hub is a connectivity device that connects computer in a star topology. It containsmultiple openings (ports) for connecting to network components.A Bridge is a device that passes data-packet between multiple network segments thatuses the same communication protocol (set of rules or standards which help to communicatewith between two or more than two computers).A device used to interconnect the media segments of an extended network is called Repeater.Router is a device that enables all users in a network to share single connection to the Internet.A Modem is a device that allows a computer to transmit information over a telephone line.It is connected with a computer and a telephone line.Novell Netware, Windows NT, Linux etc. are Windows based networking operating systems.Centralized Networks, Client/Server and Peer-to-Peer Networks are two types of networkservices.

Progress Check


Computer Network

Section B: Answer the following questions. ......1. What is communication? Give the types of communication.2. What is globalization?3. What is telecommunication? Give few examples of wired and wireless media.4. What is a computer network? Give any four advantages of networking.

5. What is a Server? What are the different types of servers? Explain each.6. What is a Client computer? How does a client computer differ from workstation?7. What is an ISP? Write any five ISPs of your town/city.8. Write short notes on: 1. LAN 2. MAN 3. WAN

9. What is topology in network? What are its types?10. What is a NIC card? In what type of networking it is generally used?11. Write short notes on the following:

i) Hub ii) Bridge iii) Repeater iv) Router

12. What is a Modem? Explain the working of a modem with a suitable diagram.13. Write short notes on:

a. Novell Netwareb. Windows NT

c. Linux15. What is Network Operating System? Give any four examples of NOS.16. What do you mean by Network Services? What are its types? Explain.

Section C: Insert the most suitable word/s in the blanks. ......1. ____________ means a medium of expressing and receiving information between two or

more people.2. Data communication is done through ________ or _________ medium.3. _________ means two ways communication and _________ means one way communication.

4. ________ medium contain a conductor made of copper or silver wires.5. Unbounded media uses a transmission __________ to send data signals.6. A __________ is a computer that provides resources to other computers in a network.7. A __________ is a computer that accesses data and information from the __________ in a

computer network.8. A __________ server provides shared hard disk in a computer network.9. A __________ server provides shared printer in a computer network.10. A __________ server provides shared modem in a computer network.

11. Interconnection of computers through cables within a single building or a room is called as__________ __________ __________.

12. Interconnection of computers through different network connecting devices between differentcities is called as __________ __________ __________.


Computer Network

13. Network of computers through satellites between various countries is called as ____________________ __________.

14. The full form of NIC is __________ __________ __________.

15. In a __________ topology, computers are arranged in a linear fashion.16. In a __________ topology, computers are connected with the help of a hub.17. A __________ interconnects media segments of an extended network.18. A modem converts __________ signals into __________ signals and transmits to the other

computer.19. __________ __________ is the oldest PC-based product in the network operating system

category.20. __________ network operating system is not as user friendly as Windows NT or Novell

Netware.

Section D: Choose the best answer. ......1. Which of the following is not type of communication?

a. Simplexb. Duplexc. Triplexd. None

2. Network of computer links:a. Computer and computerb. Computer and computer teacher

c. Printer and modemd. Cables and UPS

3. Electromagnetic signals include:

a. Radio wavesb. Infrared lightc. Ultraviolet raysd. All of the above

4. The unbounded media has advantages:a. easy to installb. easy to reconfigure

c. afford client machines mobilityd. All of the above


Computer Network

5. Which of the following are network connecting devices?a. Cables

b. Hubsc. Bridgesd. All

6. A computer that provides different resources to other computers in a network.a. Clientb. Serverc. None

d. Both A and B

7. A computer that accesses data and information from the server in a network.a. Client

b. Workstationc. Noned. All

8. ISP stands for __________.a. Internet Security Provisionb. Internet Service Providerc. Internet Security Provider

d. None

9. In this type of network, all computers are contained in a single building or a room.a. LAN

b. MANc. WANd. None

10. Here, computers of different countries are interconnected via telecommunicationlinks, microwaves or satellites.a. LANb. MAN

c. Noned. Both A and B


Computer Network

11. In this topology, computers are arranged in a linear fashion.a. Starb. Bus

c. Meshd. None

12. In this topology, computers in a network are connected via a central device called

hub.a. Bridgeb. Routerc. Hub

d. Repeater

13. In this topology, computers in a network are arranged in a circular fashion.a. Ring

b. Starc. Meshd. None

14. Mesh topology is also called as __________ topology.a. Starb. Hybridc. Bus

d. None

15. A device that is installed in a computer so that it can be connected to a network.a. Hub

b. NIC cardc. Bridged. None

16. It is a connectivity device that connects computers in a star topology.a. Bridgeb. Repeaterc. Hub

d. All


Computer Network

17. One of the following devices is used to transmit data and information through atelephone line.

a. Hubb. Repeaterc. Modemd. None

18. Which of the following is the oldest PC-based product in the networking operatingsystem category?a. Linux

b. Novell Netwarec. Windows NTd. Windows Server

Section E: State the following statements are True or False. ......1. Networking is essential for sharing data and information.2. Only cables are used in networking computers.

3. We can share a single printer in a computer network.4. A server is dedicated to the task of providing network services to the other computer

connected in a network.5. We can access Internet facility from an ISP.

6. Communication server provides shared modems.7. A File server provides shared hard disk.8. A LAN refers to network of computers between different countries.9. A WAN refers to network of computers in a single building or room.

10. Cable connection is used in a WAN.11. The linear cable is terminated at both ends to avoid signal reflection at the ends of the cable.12. Disadvantage of a bus topology is that the entire network fails if there is any fault at any

point on the cable.

13. A hub is a network-connecting device.14. In a Ring topology, each computer waits for its turn in the ring.15. Incase of LAN, satellite is the main connecting device.16. A modem helps in transmission of data and information through telephone line.

17. The fastest PC-based network operating system is Novell Netware.18. Windows NT Workstation and Windows Server are the two different versions of operating

system created by the Microsoft Corporation.19. Linux is very user friendly and easy to use.

20. Client/Server model provides distributed network services while Peer-To-Peer model offerscentralized network services.

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