introduction to hardware and networking module hardware and networking1.1

Module hardware and networking

Introduction to hardware and networking

1.1


What is a computer?

• A programmable electronic device that can process, store and retrieve data

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Types of computer

• Microcomputers (or personal computers)– Desktop (single location)– Laptop or Notebook

(mobile)– Tablet (mobile, touch

screen, stylus)– Netbook (smaller mobile)– Personal Digital

Assistant/Smart Phones (handheld)

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Functional classification

• Server– Primary task is storing and retrieving large

quantities of data (network)• Web server, servers in each office

• Workstation– High end-computer designed to be used by one

person• Office desktops

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About Hardware

• Hardware is any physical piece of equipment, called a device, that is both connected to your computer and controlled by your computer

• Comprehensive term for all of the physical parts of the computer.

• Refers to objects you can touch, like disks, disk drives, display screens , keyboard, printers and chips.

• Internal devices are placed inside the case of the computer

• External devices remain outside the case of the computer

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About software

• Exists as ideas, concepts, and symbols• Provides instructions for the hardware to

accomplish tasks.• Can not be touched like the hardware. All

parts are inside the computer.

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System unitpower supply

ports

drive bays

processor

memory

sound card

video cardmodem card

network card1.7


Interface between computers and devices

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Inside the PCprocessor chip

adapter cards

memory chips

memory slots

motherboard

Expansionslots for adapter cards

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Printers

• Types of printer– Laser, inkjet (ink dispersion), solid ink, thermal

printers, and impact printers

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Laser printer

• Uses mechanical, electrical, and optical technologies

• Capable of handling and printing large volumes quickly and continuously

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Dot matrix printers

• Overview of dot matrix printer technology:– Lesser quality of other printers– A print head moves across the width of the paper– Pins are used to print a matrix of dots on the page• Can print multicopy documents and Last Forever• Pins shoot against a cloth ribbon. Ribbon is used for ink

and to lubricate• Ribbon impacts the paper, depositing the ink

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Inkjet printers• Overview of inkjet printer

technology:– With Inkjet, ink is applied to

paper using a matrix of small dots• Plates with magnetic charge

direct path to the page– Older inkjets have lower

resolution, but today’s are photo quality

– Images smudge on inexpensive paper• Especially with higher

resolution (wet paper)– Usually cost less

• Print color inexpensively

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Thermal printers

• Overview of thermal printer technology– Nonimpact printers that use heat to produce

output– Popular in retail for bar codes and price tags– Wax-based ink heated by heat pins– Print head is as wide as paper, so does not move – Heat pins melt ink onto paper

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Networking - Basics

• Network defined• The difference between Standalone and networked

Systems• Advantages of networking• Disadvantages of networking• Why use network– To share information– To Share hardware and software– Centralizing administration

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Types of networks

• Classification based on geographical area– LAN– WAN

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Network configuration

• Classification based on how computers behave in a network

• Two classifications are– Peer-to-Peer network– Server based network

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Server based network

• Designated computer to administer• Resources centralized• Supports larger networks• Strong security• Expensive

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Topologies - Physical

• Refers to physical arrangement of– Computers– Cables– Other components

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Star topology

• Connected to a central hub

• Easier administration• Difficult to install• High cable cost• Hub failure fails the

network

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Star bus topology

• Combination of several stars

• Augments systems in network

• Failure of hub/s fails the network

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Network hardware

• Hub• Cables• Connectors• Switches• Routers

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Hub

• Standard component in Star topology• Types– Active, Passive– Manageable

• Easier administration• Centralized monitoring of network

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Cables

• Wires the LAN, usually• Transmit signals through network• Different cable considerations according to need• Types– Co-axial– Twisted Pair– Fiber-optic

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Twisted pair

• Pair of insulated copper wires

• Types– Shielded(STP)– Unshielded(UTP)

• UTP common in LAN• Max. cable length – 100

meters

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Connectors for UTP

• RJ – 11 and RJ – 45• RJ11 in telephone

cables – 4 cable connections

• RJ45 in LAN cables – 8 cable connections

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Cable connection method

Used to connect a system to hub or switch in LAN

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Network operating systems

• Co-ordinates hardware and software• Ties together all computers and peripherals• Provides security by controlling access to

resources and peripherals shared• Manages users• Example – Windows 2003 and Windows 2008

server operating systems

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Postmaster’s role in managing windows network

• Ensure that the administrator’s account is not known to all users in the office

• Ensure that ordinary users are not logging in with administrative rights

• Ensure that one user with account operator right in the server is created for PM or one of the supervisors – helps in creating users in the absence of administrator

• Ensure that server is protected physically

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Password Security• Do not allow blank

passwords• Assign a Password for the

Administrator Account• Determine who has Control

over Passwords• Educate Users on How to

Use Passwords– Avoid obvious associations, such

as a family name– Use long passwords– Use a combination of uppercase

and lowercase characters

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User level security in domain

Module hardware and networking 1..31

• Set logon hours according to requirements• Set expiration for User accounts• Specify the Computers from Which a User Can Log

On– Domain users can log on at any computer in the domain,

by default– Domain users can be restricted to specific computers to

increase security


Database management and SQL Server

• Overview of Databases– Data is a collection of raw facts– Database is a collection of data stored inside tables– Provides centralized control of data– Relational database management

• Advantages– Reduces data redundancy– Can be shared among many users– Security around access can be implemented

• Examples– SQL 2000 and SQL 2005

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Administrative tasks in SQL Server

• SQL Server enterprise manager (SQL 2000) and SQL Server management studio (SQL 2005 /2008) are used to perform admin tasks

• The admin tasks involved are– Manage security– Manage databases– Manage backups– Follow up events

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Backup of database - Overview

• Backup is a copy• Stores copy in another media like– Local Hard disk– Tape disk, DVD, CD, external hard disk– Network drive

• Helps recover data in case of failure and also to recall past data for investigation or auditing

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Backup types

• Full or complete• Differential• Transaction log

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Backup strategy

• Good strategy helps restore data with minimum down time

• Minimizes permanent loss of data• A good plan should involve minimum shut down of

operations for backup• Good strategy should put the system back to what it

was before failure• Good protection should exist for the backup media –

preferably stored offsite

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Security in SQL Server

• Strong password for sa• Password for the sa secured by divisional head• Postmaster to ensure that unauthorised

administrative access to admin tools is prevented

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introduction to hardware and networking module hardware and networking1.1

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