Chapter 01 Network Fundamentals

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LCS 212:

NETWORK PRINCIPLES ANDPROGRAMMING

MS. KATHRINA S. TAMBOTInstructor, CCS


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Chapter 01

NETWORK FUNDAMENTALS

CollegeofComputerScience,DMMMSU-SLUC


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WHAT IS A NETWORK? A simple collection of computers at one location

that have been tied together using a particular

connectivity medium (such as network cabling or

wireless technology) to a giant global network, such

as the Internet, that uses a number of differentconnectivity media, including microwave and

satellite technology.

Consist of the computers, the connectivity medium

(such as copper wire or fiber optic cables), and otherdevices, such as hubs, switches, and routers, that

make up the network infrastructure. Some devices,

such as network interface cards, serve as the

computer's connection to the network.



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WHAT IS A NETWORK? Two connected computers qualify as a network

Networks are not networks just because they

contain highly complex connectivity strategies. Two

computers running the Windows Me operating

system can be joined together by their COM ports(also known as serial ports) by a single serial cable.

Is this a network? Sure, it allows you to share

resources between the two computers and

therefore meets the basic definition of what anetwork is.



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WHY NETWORK YOUR COMPUTERS? File sharing. Networking computers makes it very

easy for the users on the network to share data files.

Files on a particular user's computer can be shared

on the network or files can be placed on a file

server, which provides a central location for all files

needed by the users on the network.

Hardware sharing. Users can share devices such as

printers, CD-ROM drives, and hard drives. Once

networked, computers can share their own localdevices, such as CD-ROM and hard drives, or take

advantage of high-speed printers or other devices

that are provided by a particular server on the

network.



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WHY NETWORK YOUR COMPUTERS? Program sharing. Applications such as spreadsheets

and word processors can be run over the network.

You keep most of the files that make up the

application on a special application server on the

network. This makes installing the software on a

computer easier. It also makes upgrading an

application easier because the upgrade only has to

be performed on the server itself.



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WHY NETWORK YOUR COMPUTERS?User communication. Networks allow users to take

advantage of communication media such as

electronic mail, newsgroups, and video

conferencing. Because voice, pictures, and video can

be moved across the network as data, network

communication is certainly not limited to just text

messages.

Multiplayer gaming. While this certainly isn't a

reason for networking computers in a businessenvironment, individuals who set up home-based

peer-to-peer networks can take advantage of a large

number of computer games that provide support for

multiple players on a network.



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CLIENTS AND SERVERS A CLIENT is a computer that allows a user to log on

to the network and take advantage of the resources

available on the network.

A client computer will run a client operating system.

The purpose of the client is to get a user onto thenetwork.

Don't usually have the processing power, the storage

space, or the memory found on a server because

the client does not have to serve up resources toother computers on the network.



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CLIENTS AND SERVERS A SERVER is typically a much more powerful

computer that runs a network operating system

(NOS) such as Microsoft Windows Server 2003 or

Novell NetWare.

The server provides centralized administration ofthe network and serves up the resources that are

available on the network, such as printers and files.

The administrator of the server decides who can and

cannot log on to the network and which resourcesthe various users can access.



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CLIENTS AND SERVERS PC networks consist of clients and servers.



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CLIENTS AND SERVERS Because client and server computers both have

processing capabilities, the workload on a PC

network can be distributed between the client and

the server.

You may hear the term workstation usedinterchangeably with client in reference to the

computers used by network users to access the

network. In reality, workstation more commonly

refers to higher-end client machines that requiremore memory and processing power to run more

complex software, such as the design software used

by engineers.



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USERS AND ADMINISTRATORSUSERS make up most of the folks you find on a PC

network.

They are there to access network resources.

A user requires a user logon and password to gain

access to the network.



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USERS AND ADMINISTRATORSADMINISTRATORS serve as the caretaker of the

network.

The administrator controls the network servers.

This means that network access and the level of

access is controlled by the administrator using thetools provided by the NOS.

Most network operating systems supply the network

administrator with the ability to monitor network

use, including user logons. The administrator is alsoresponsible for disaster planning and securing the

network resources from outside attack and virus

infestation.

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terScience,DMMMSU-SL

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USERS AND ADMINISTRATORSOne of the most difficult aspects of being a network

administrator is convincing users that the access

levels and security policies used on the network are

there for a purposeand that purpose is to protect

the valuable corporate resources found on the

network.

Although network administrators are typically

thought of as dime-store dictators or control freaks

by the users, administrators are typically faced withlong hours and a great deal of hard work to keep

their networks up and running.

CollegeofCompu


UC


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USERS AND ADMINISTRATORSOne of the most difficult aspects of being a network

administrator is convincing users that the access

levels and security policies used on the network are

there for a purposeand that purpose is to protect

the valuable corporate resources found on the

network.

Although network administrators are typically

thought of as dime-store dictators or control freaks

by the users, administrators are typically faced withlong hours and a great deal of hard work to keep

their networks up and running.

CollegeofCompu


UC


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USERS AND ADMINISTRATORSNetwork administrators also supervise technical

employees and be responsible for the budgeting and

procurement related to the computer network.CollegeofCompu


UC


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UNDERSTANDING LAN DATA TRANSMISSION A bit is the smallest unit of data found on a

computer.

Bits are represented by either a one (1) or a zero (0).

When you type a letter or create a spreadsheet, you

see your data as words in paragraphs or numbers ina column. Your computer sees this information as

binary dataones and zeros.

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UNDERSTANDING LAN DATA TRANSMISSIONOn a computer, data in the form of a bit stream

travels in parallel across wires arranged on the

motherboard.

These parallel wires on the motherboard are

referred to as the data bus.When data is required by the computer's processor

from the computer's hard drive, the data moves

along the bus, which is very much like a multilane

superhighway, allowing several bit streams to movesimultaneously.

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UNDERSTANDING LAN DATA TRANSMISSION To actually move data from one computer to

another on the network, there obviously needs to

be some kind of network medium; copper wire is

actually the most often used network medium.

Unfortunately, no matter what type of networkmedium you choose, the data can only travel along

it as a single bit stream, which is referred to as a

serial transmission.

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UNDERSTANDING LAN DATA TRANSMISSION A NETWORK INTERFACE CARD (NIC) is a device is

needed to take the parallel data from the computer,

which is like a multilane super highway, and

condense it into a serial transmission, which is the

equivalent of a one-lane road.

This device also provides the connection between

the PC and the network media.

The NIC contains a transceiver (a transmitter and

receiver) that is able to convert data from parallel toserial, and vice versa.

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UNDERSTANDING LAN DATA TRANSMISSION A NIC can come in the form of a separate card that

you install in the computer.

Some personal computers, such as the Apple iMac,

come with a built-in NIC that's ready to go.

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UNDERSTANDING LAN DATA TRANSMISSIONNetwork interface cards provide the physical

connection between a computer and the network.CollegeofCompu


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Chapter 01 Network Fundamentals

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