A.G.T.I ( Second Year )

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A.G.T.I ( Second Year )



Implementing Hard Drives

1. Explain the concepts in Partitioning Hard Drives?

(8 marks)

Partitions are electronic, logical divisions of a hard drive into groups of cylinders. A

might have only one physical hard drive, for example, but it can have anywhere from 1 to
24 logical drives, which are assigned the

drive letters from C: to Z: .

Partitions exist for three reasons. First, when DOS was initially designed to use hard drives,

the method employed by DOS to store files limited the largest hard drive size to 32MB. Microsoft
included partitioning in DOS 3.3 to enable PCs to use larger physical hard drives by creating
multiple logical drives, up to 32 MB each.

Second, partitions en
able you to organize a drive in a way that suits your personal taste.
Finally, partitioning enables a single hard drive to store more than one operating system (OS). One
OS could be stored in one partition and another OS stored in a second.

The different v
ersions of Windows in wide use today offer two radically different styles of
partitioning, called basic disks and dynamic disks. All versions of Windows can create partitions
with basic disks: only Windows 2000 and XP can create dynamic disks.

2. Explain
about Partitioning Basic Disks?

(8 marks)

Partitioning creates a couple of items on a disk, the
master boot record

(MBR) and a
partition table
. When the computer first boots to a hard drive, it looks for the very first sector of the
physical drive, called

boot sector
. The boot sector contains the MBR and the partition table. The
MBR has only one job: to look for a partition in the partition table with a valid operating system.

All hard drive partition tables support up to four bootable partitions, but
the vast majority of
systems only have one bootable partition. Only one partition at a time can be made the active

The first sector of the first cylinder of each partition also has a boot sector called the
boot sector
. While the ‘’ main ‘
’ boot sector defines the partitions, the volume boot sectors store
information important to each partition, such as the location of the operating system boot files.

3. Explain two types of partitions in short notes?

(8 marks)

A hard drive may have up to

four partitions. These partitions divide into one of two types:
primary and extended.

Primary Partitions

Primary partitions store the OS (s). If you want to boot from a hard drive, it must have a
primary partition. Therefore, the MBR must check the partit
ion table for a primary partition. The
primary partition is C:, and that cannot be changed. A hard drive can have up to four primary
partitions. Hard disk can have up into four chunks and installed a different OS in each. In order to
used a third

party to

Active Partition

When a hard drive stores multiple primary partitions, each with a valid operating system,
the MBR will seek an OS to boot on the currently active primary partition. As mentioned
previously, only one primary partition may be active at a


Extended Partition

A hard drive may or may not have the other basic disk partition type

an extended
partition. Extended partitions are not bootable, and a hard drive can only have one extended
partition. If a hard drive has an extended partition,
it takes up one of the areas in the partition map
of primary partitions.

You can use extended partitions in situations where you want to chop a drive into multiple
drive letters. When you create an extended partition, it does not automatically get a drive
Instead, you divide the extended partition into‘’ logical drives’’. An extended partition may have
many logical drives.

Extended partitions always requires two steps: First, you make the extended partition, and
then you must create logical drives w
ithin that extended partition. This two
step process often
forget to create logical drives in the extended partition and wonder why they don’t see any new
drive letters in My Computer when they finish partitioning.

Each version of Windows offers a differe
nt tool for partitioning hard drives. In Windows
9x/Me, you use a program called FDISK to partition drives. Windows NT 4.0 uses the far more
powerful graphical Disk Administrator tool. Windows 2000 and Windows XP use an enhanced
version of the Disk Adminis
trator, called Disk Management.

4. Explain briefly on FAT file system?

(16 marks)

The base storage area for hard drives is a sector; each sector stores up to 512 bytes of data .If
an OS stores a file smaller than 512 bytes in a sector, the rest of the s
ector goes to waste. Accept
this waste because most files are far larger than 512 bytes. The OS needs a method to fill one
sector, find another that’s unused and fill it, continuing to fill sectors until the file is completely

Using a special data
structure to keep track of stored data on the hard drive, and Microsoft
called this structure the file allocation table (FAT). The left column gives each sector a number.
The area is (64K) sector from 0000 to FFFF. This type of FAT a“16
bit FAT ” or “FAT16
”. Floppy
drives also use FATs, but their FATs are only 12 bits.

Windows NT 4.0



Windows 95,95A


Windows 95B(OSR2),98, 98SE, Me



Windows 2000




Windows XP




The right
hand side of the FAT
contains information on the status of sectors. If it finds a bad
sector, it places a special status code (FFF7) in the sector’s FAT location, indicating that sector is
unavailable for use. Formatting also marks the good sectors as 0000.

Clustering simply m
eans to combine a set of contiguous sectors and treat them as a single unit
in the FAT. These units are called file allocation units or clusters. Each row of the FAT addressed a
cluster instead of a sector. Unlike sectors, the size of a cluster is not fixe
d. This improved FAT16
still only supported a maximum of 64K storage units. The new FAT16 could support partitions up
to 2GB.

FAT16 Partition size

Sectors per Cluster

Cluster Size

16MB to 128MB



129MB to 256MB



257MB to 512MB



513MB to



1025MB to 2GB



Each sector holds 512bytes of data, so cluster capacity will always be half the number of sector per cluster.

It also increased the inherent wastefulness of FAT storage. With a sector
based FAT, when
you saved a file
of fewer than 512 bytes, the excess unused space in the sector went to waste. This
changed when clusters became the smallest storage area in as hard drive. Storing files in clusters
created much greater waste due to the fact that clusters were so much larg
er. To keep the waste as
low as possible, we kept FAT16 partitions as small as possible.

5. Explain briefly on NTFS4?

(8 marks)

Windows NT 4.0 can format a drive with the NT file system (NTFS) version 4, an extremely
robust and secure file system. NTFS
offers four major benefits over FAT 16. First, NTFS utilizes
an enhanced file allocation table called the Master File Table (MFT). An NTFS partition keeps a
backup copy of the most critical parts of the MFT in the middle of the disk reducing the chance tha
a serious drive error can wipe out both the MFT and the MFT copy, Immovable chunk in the
middle of the drive; that’s the backup MFT.

Second, NTFS views individual files and folders as objects and provides security for those
objects through a feature call
ed the Access Control List (ACL). Without NTFS, would have no
security over his files or folders at all.

Third, NTFS4 enables you to compress individual files and folders to save space on a hard
drive. Compression makes access time to the data slower.

lly, when you format a drive with NTFS, Disk Administrator enables you to make some very
cool drive setups. The size of a volume can extend to take more hard drive space. To do this on a
signal drive or even across drives

a process called spanning by the

rest of the world but called a
Volume Set in Disk Administrator. To extend a volume, click the volume, hold down the CTRL
key, and then alternate

click free hard drive space. Select Extend Volume Set from the menu.

6. Answer the order in which hard drive
s receive their drive letters?

(8 marks)

Hard drives receive their letters:

1. Primary partition of the primary master drive

2. Primary partition of the primary slave drive

3. Primary partition of the secondary master drive

4. Primary partition of the seco
ndary slave drive

5. All logical drives in the extended partition of the primary master drive

6. All logical drives in the extended partition of the primary slave drive

7. All logical drives in the extended partition of the secondary master drive

8. All lo
gical drives in the extended partition of the secondary slave drive

9. All non
hard drives attached to an IDE controller gets a drive letter

7. Explain the function of the followings.

(8 marks)






Disk Cleanup

(a) Scandisk

al clusters on hard drives sometimes go bad. So it’s important to check occasionally
for bad clusters on drives. The tool used to perform this check is called Scandisk.

ScanDisk does far more than just check for bad clusters. From time to time, the underly
links between parent and child folders are lost, so Scandisk checks every parent and child folder.

The best part of ScanDisk is that it works automatically. The Windows 9x/Me version of
ScanDisk gives you a choice between Standard and Thorough testing,

as well as an option to have
it automatically fix any errors it finds. As a rule, you should also always check the Automatically
fix errors check box.

A reasonable maintenance plan would include running ScanDisk about once a week.
ScanDisk is fast (unless

you use the Thorough option).

(b) Defragmentation

Fragmentation of clusters can make your drive access times increase dramatically. So need
to defragmentation your drives as part of weekly maintenance.

To access the Windows 9x^ME Disk Defragmenter progr
am, choose Start

Programs│Accessories │ System Tools│Disk Defragmenter. Defragmentation takes quite a while
if you haven’t done it before.

Simply running Disk Defragmenter with the default setting is fine in most situations, but
there are some specialized settings that y
ou may want to employ. Defrag and Scandisk are two
maintenance tools that everyone should run on their systems.

(c) Disk Cleanup

Every hard drive will eventually become filled with lots of unnecessary trash. All versions
of Windows starting with Windows 9
8 have a powerful tool called Disk Cleanup. You can access
Disk Cleanup in all versions of Windows by choosing

Start│ Programs│Accessories │ System
Tools│Disk Cleanup.

Files in the Recycle Bin

When you delete a file, it isn’t really deleted. It’s placed in the
Recycle Bin just in case you decide you need the file later.

Temporary Internet Files

When you go to s we
b site, Windows keeps copies of
the graphics and other items so that the page will load more quickly the next time you
access the page.

Downloaded Program Files

Your system always keeps a copy of any Java or
ActiveX applets that it downloads.

Temporary Fi

Many applications create temporary files that are supposed to be
deleted when the application is closed.


Understanding WEIndows

1. Briefly discuss about My Computer?

(8 marks)

My Computer provides access to all drives, folder
s, and files on the system. To open My
Computer simply double
click the My Computer icon on the Desktop. When you first open My
Computer in Windows 98, it displays all the drives on the system. My Computer in what Microsoft
calls the Web view

the left sid
e of the window provides details of whatever icon you currently
have highlighted. If you use Windows 95 or Windows NT, or if you choose to turn off this option
in Windows 98/Me or Windows 2000, you get a less sophisticated window. Windows XP offers a
sticated My Computer, with all details and common tasks displayed on the left pane.

To view the contents of a drive or disk, double
click the corresponding icon in My
Computer. Windows assigns different icons to different types of files based on their ext
ensions, the
digit set at the end of a filename, such as .EXE,.JPG.

2. What is Control Panel? Explain it?

(8 marks)

The Control Panel handles most of the maintenance, upgrade, and configuration aspects of
Windows. As such, the Control Panel is the
first set of tools for every tech. Select Start│ Settings
│Control Panel to open the Control Panel.

A large number of programs, called applets, popular the Control Panel. The names and
selection of applets will vary depending on the version of Windows and
whether any installed
programs have added applets. But all versions of Windows share many of the same applets,
including Display, Add/Remove Programs, and System

What I call the Big Three applets for techs.
The System applet gives you access to essential
system information and tools, such as the Devices

The Control Panel applets enable you to do an amazing array of things to a Windows
system. Each applet displays text that helps explain its functions. The Add New Hardware applet.

3. Briefly Discu
ss the Device Manager?

(8 marks)

The Device Manager
enables techs to examine and configure all the hardware and drivers in
a Windows PC.

The Device Manager differs among the various versions of Windows, but most often you go
to the Control Panel and click

the System applet. Windows 98 System applet’s System Properties
screen. You access the Device Manager by selecting the Device Manager tab at the top of the
applet. The System applet’s System Properties screen for Windows XP, which requires you to
select t
he Hardware tab and then click the Device Manager button in the middle of that tab.

The Device Manager in all versions of Windows

except Windows NT 4.0

displays every
device that Windows recognizes. Windows 98 Device Manager screen with all installed de
vices in
good order with the exception of the mouse. If Windows detects a problem, it shows the device
with a red ‘x’ or a yellow exclamation point.

The Device Manager organizes devices in special groups called

All device of the
same type are group
ed under the same type heading. To see the devices of a particular type, you
must open that type’s group. The Ports type opened, revealing the COM and LPT ports on the

4. Explain the Registry Component and Any three?

(8 marks)

The Registry is org
anized in a tree structure similar to the folders in the PC. Once you open
the Registry Editor in Windows 9x/Me, you see six main subgroups, or root keys:








This root key defines the standard class objects used by Windows 9x. A class object is a
named group of functions. Pretty much everything that has to do with files on the system is defined
by a class object. For example, a MIDI ( Musical
Instrument Digital interface) sound file is defined
using two class objects. If you search the Registry for the .MID file extension, you will find the first
class object, which associates the .MID file extension with the name ‘’midfile’’.


Windows 9x/Me can be configured to support more than one user on the same PC, storing
personalized information such as colors, screen savers, and the contents of the Desktop.
HKEY_USERS stores all of the personalized information for all

users on a PC. HKEY_
CURRENT_USER stores the current user setting, which makes it a good place to fix
personalizations such as fonts, icons, and colors on systems that are set up to support multiple


This root key contains all the

data for a system’s non
specific configurations. This
includes every device in your PC, including devices that you have removed.


If values in HKEY
MACHINE have more than one option, such as two different
monitors, this root

key defines which one is currently being used. Because most people have only
one type of monitor and similar equipment, this area is almost never touched.


This is Registry data stored in RAM to speed up system configuration. A snapshot of a
hardware in use is stored here. It is updated at boot and when any changes are made in the system
configuration file.


Maintaining, Optimizing, and Troubleshooting Windows 9x
and Windows Me

1. Explain the concept of Virtual Memory?

(8 marks)

All versions of Windows use
virtual memory

mapping a portion of the hard drive with
memory addresses to mimic RAM.

Windows creates a swap file that enables it to have more programs open on the screen than it
could normally hold in re
al RAM. The swap file in Windows 9x/Me is called WIN386.SWP, while
the Windows NT/2000/XP swap file is called PAGEFILE.SYS. Windows sets the initial size of the
swap file automatically according to the amount of free space available on the C: drive.

The Windows NT/2000/XP swap file settings can be found by alternate
clicking the My
Computer icon on your desktop, selecting the Advanced tab, and then clicking the Performance
Options button. The Performance Options window shows several radio buttons

clicking the Change
button opens the Virtual Memory dialog box.

The most common reason for relocating the default swap file is to move it to some drive
other than C: Many systems tend to fill up the C: drive, so little or no room is left for th
e swap file.
The swap file can use only the free space on a drive. When the space is filled, the swap file can’t
get any larger, resulting in the nasty “Not Enough Memory” error. The solution is to move the swap
file to another drive.

To move th
e file in Windows 9x/Me, click the Let Me Specify My Own Virtual Memory
Settings radio button and select another drive. In Windows NT/2000/XP, click the drive letter to
which you wish to move the swap file, then click the Set button, and close back out of
the various

The minimum and maximum swap file sizes. Windows 9x/Me sets the minimum to zero
and the maximum to the size of the free space on the drive, whereas Windows 2000 sets a
minimum and maximum by a fairly complex set of rules.

2. Answer how to create a window startup disk?

(8 marks)

All versions of Windows 9x/Me provide the capability to create a startup disk. A


is a bootable floppy disk that, in case of an emergency, enables you to boot to an A: prompt.

The follo
w these steps:


Click Start [Setting] Control Panel to open the Control Panel.


Locate the Add/Remove Programs icon and click it.


Click the Startup Disk tab.


Get a blank floppy disk, and insert it into the floppy drive.


Click Create Disk.

Windows will then c
reate a startup disk. This disk contains just enough files to perform
basic troubleshooting. After Windows has created the startup disk, take it out of the floppy drive.

One of the most important jobs for a startup disk is to enable you to gai
n access to your

3. Explain how to install a driver for specific device?

(8 marks)

Driver installation in a PnP system is highly anticlimactic in most cases. You get to watch
Windows discover the new device and show the famous “Windows has discov
ered new hardware”

Windows drives manifest themselves as special text files with the INF extension, called INF
files. The INF file will usually also come with any other files the hardware device needs, but the
INF file is what Windows will look for

when it prompts for a device driver. This often gets techs in
trouble as many devices will come with many different device drivers for different operating
systems with each driver getting its own directory on the installation CD
ROM or floppy diskette.

you’re installing a new device and Windows can’t find the device driver on the installation disk,
check to make sure the INF file isn’t tucked away in some subdirectory on the install disk. If it is,
just point Windows to the right folder.

Many systems give the “Windows has found unknown hardware and is installing
software…”message. This usually comes from installing two devices at once, one depending on the
other for connection to the system.

4. Explain how to trouble
shoot if w
indows won’t Boot to GUI?

(16 marks)

. The first thing to blame is a corrupted swap file
. Boot into Safe mode and disable virtual
memory. Restart the system when prompted by Windows. If the swap file was the culprit,
the system will boot normally, althoug
h it may run rather slowly. Turn the swap file swap
file back on and reboot again.

. The next thing to try is a step
step configuration from the boot menu
. This will usually
give you a good feel as to which of the following areas should be checked next

. You may need to restore the previous Registry copy.
Use whatever tool you have to
restore a known good copy of the Registry. If you don’t have one, try replacing
SYSTEM.DAT and USER.DAT with SYSTEM.DAO and the USER.DAO. All of these
files are hidden a
nd read
only, so use the ATTRIB command from the startup disk to turn
off the attributes. It would look something like this:




h c: /WINDOWS/SYSTEM/*.dat


If you have Windows 98, boot to the

startup disk and run the Windows Registry
Checker tool. From the A: prompt, type the following command:


Try booting again. If the Registry was the problem, you should now boot normally.

. Resource conflicts can sometimes
prevent the GUI from booting
. A quick boot to
Safe mode and a check of the Device Manager should confirm this. Fix resource conflicts as
described previously.

. A bad driver may cause problems.
For this, use the
Automatic Ship Driver

(ASD) Tool in
Safe mode. You can find it under the Tools menu in the System Information tool, although I
usually go to Start/ Run and type in ASD. The ASD looks over your log files and prevents
any drivers that failed previously from loading at the next b
oot. If this works, check for a
driver update or remove the offending device.


Sometimes some of the core Windows files get corrupted.

If you have Windows 98/Me, you
can run the System File Checker from a command prompt as follows:


oesn’t show much on the screen, but it will restore any corrupted core file from its
own backups automatically. You must reboot after running SFC so that Windows can reload
the core files.

Chapter 16

Maintaining Optimizing, and Troubleshoot
ing Windows NT, 2000 and XP


Explain how to install and remove software? (16 marks)

Installing Software

Most application programs are distributed on CD
ROMs. Luckily, Windows
supports run, a feature that enables it to look for and read a special file calle
d Auto run
immediately after a CD
ROM is inserted and then run whatever program is listed in
Autorun.inf. Most application programs distributed on CD have an Autorun file that calls up
the installation program.

Sometimes, however, it is simply necessary to

institute the installation sequence by
the user. Perhaps the install CD lacks an Autorun installation program, or perhaps Windows
is configured so that Autorun programs must be started manually. In some cases, a CD may
contain more than one program, and t
he user must choose which f them to install. Beginning
the installation manually is a simple and straight forward process using the Add or Remove
Programs applet in the Control Panel. Click the Add New Programs button, follow the
prompts, and provide the d
isk or location of the files.

Typically the user will have to accept the terms of the software license before the
user is allowed to install the application. These steps are not optional since the installation
simply won’t proceed until he accept all terms

the software manufacturer requires and enter
the correct code. The user may also be asked to make several decisions during the
installation process.

Removing Software

Each installed application program takes up space on the computer’s hard disk, and
grams that no longer need or use simply waste space that could be used for other
purposes, so removing them can be an important piece of housekeeping.

To remove a program from a Windows PC is the same as install. When possible, use
the applications’ own un
install program. The uninstall program is listed under the
application icon off the start menu.

If an uninstall program is not available, then use Windows’ Add or Remove
Programs applet from Control Panel. Select the program want to remove and click the
ange or Remove button. It doesn’t disappear in a flash. First, a message appears warning
that the program will be permanently removed from the PC. If it is sure to continue, click

Clicking the Change/Remove button will start the application’s install
program. So
that the user can modify the installed features. This is completely a function of the program
the user is attempting to remove. The end result should be the removal of the application
and all of it’s pieces and parts, including files and Regist
ry entries.



Explain how to add a plug & play device and non plug & play device. (8 marks)

Adding a plug & play device

It is simple to install a new plug and play device to a Windows 2000 / XP computer.
Simply plug it in and Windows will detect

it and install the driver. For the safe side, always
read the documentation for the new device, just in case there is a new twist, like having to
install the driver first.

If windows does not detect the newly connected device, use the Add Hardware

to get the device recognized and drivers installed. It’s on the Hardware tab of the
System Properties box. This is what passes for a manual device installation today.

Adding a non
plug & play device

The user also has to know how to install non
plug and
play devices, also called
legacy devices. Windows even comes with drivers for non
plug and play devices. Some
devices have Windows 2000 drivers, which might work in Windows XP. Round up the
driver beforehand, read any documentation find on the device, and
then install the hardware.
If there is a setup program with the driver, run that now.

If there is no setup program, then call on the Add Hardware Wizard. Click Next on
the Welcome screen, and it will search for hardware that has been connected but which do
not yet have a driver installed. If it detects it, select the device and the wizard will install the
driver. The user may has to point to the source location for the driver files. If it does not
detect the device, which is very likely, it will ask if th
e hardware is connected. When the
user answer yes and click Next, it will give a list of installed hardware.

If the device is in the list, select it and click Next. In this case, once it detects the
device and installs the driver, it’s done.



xplain about System Restore. (8 marks)

System Restore is first introduced in Windows Me with further refinements in
Windows XP. The System Restore tool enables to create a restore point, a copy of the
computer’s configuration at a specific point in time. I
f there is crash or have a corrupted OS
later, the system can be restored.

To create a restore point, go to Start | All Programs | Accessories | System Tools |
System Restore. When the tool opens, select Create a Restore Point, and then click Next.
Type in

a description on the next screen. There’s no need to include the date and time
because the System Restore adds them automatically. Then click Create.

The System Restore tool creates some of the restore points in time automatically.
For instance, by defaul
t, every time the user installs new software, XP creates a restore
point. Thus, if installation of a program causes your computer to malfunction, simply
restore the system to a time point prior to that installation, and the computer should work

ng the restore process, only settings and programs are changed. No data is lost.
Your computer will include all programs and settings as of the restore date. This feature is
absolutely invaluable for over worked techs. A simple restore will fix many user



Explain briefly on the title “Safe Mode”. (16 marks)

Safe mode starts up without using some drivers and components that would
normally be started, including network support. It loads only very basic, non
specific drive
rs for mouse, VGA monitor, keyboard, mass storage, and system services.

The options available in Safe Mode are as follows;

Safe Mode with Networking

This mode is identical to plain Safe Mode,
except that there is network support. If windows won’t start up

normally, but does start up
in Safe Mode. Then reboot into Safe Mode with Networking.

Safe Mode with Command Prompt

When starting Windows in this mode, after log
on, rather than loading the GUI desktop, it loads the command prompt (CMD.EXE) as the
shell t
o the operating system. This is a handy option to remember if the desktop does not
display at all.

Enable Boot Logging

This option starts Windows normally and
creates a log file of the drivers as they load into memory. The file is named Ntbtlog.txt and
saved in the %SystemRoot% folder. If the startup failed because of a bad driver, the last
entry in this file may be the driver the OS was initializing when it failed.

Enable VGA Mode

If this mode works, it means that the video
driver is correct, but is c
onfigured incorrectly perhaps with the wrong refresh rate and/or
resolution. After successfully starting in this mode, open the Display Properties and change
the settings.

Last Known Good Configuration

When Windows fails immediately after
installing a new
driver, but before the user have logged on again, he may want to try the
Last Known Good option available from the Advanced Options menu.

Directory Services Restore Mode

This option only applies to Active Directory
domain controllers, and Windows 2000 Prof
essional and Windows XP can never be domain

Debugging Mode

In this option, Windows 2000/XP starts in
kernel debug mode. It’s a super
techie thing to do. Connect the computer to another
computer via a serial connection and as Windows starts u
p, a debug of the kernel is sent to
the second computer, which must also be running a debugger program.

Starts Windows Normally

This choice will simply start Windows
normally, without rebooting. The user already rebooted to this menu.


This choi
ce will actually do a soft reboot of the

Return to OS Choices Menu

This choice will return the user to the OS
Choices menu from which he can select the operating system to load.


Chapter 23



Explain Packets/ Frames and NI
Cs. (8 marks)

Data is moved from one PC to another in discrete chunks called packets or frames.
The terms packet and frame are interchangeable. Every network interface card (NIC) in the
world has a build
in identifier, a binary address unique to that singl
e network card, called a
Media Access Control (MAC) address. Every network card has it’s own unique MAC
address. The MAC address is 48 bits long giving over 281 trillion MAC addresses, so there
are plenty of MAC addresses to go around. MAC addresses may be

binary, but it is
represented using 12 hexadecimal characters.

All the many varieties of packets share certain comm. Features. First, packets
contain the MAC address of the network card to which the data is being sent. Second, they
have the MAC address of

the network card that sent the data. Third is the data itself, which
can vary in size depending on the type of data check is performed and information is stored
in the packet to enable the receiving network card to verify if the data was received in good

To make a successful network, the user need the send and receiving PCs to use the
same hardware protocol. A hardware protocol defines many aspects of a network, from the
packet type of the cabling and connectors used. A hardware protocol defines eve
necessary to get data from one computer to another. Two hardware protocols dominate the
modern computing landscape, Ethernet and Token Ring.



Explain the Star Bus Topology. (8 marks)

Instead of attaching each PC directly to the wire, atta
ch them via cables to special
ports on the box, and the box with the bus takes care of termination and all those other
tedious details required by a bus network.

The central box with the bus is called a hub or switch. The hub provides a common
point for co
nnection for network devices. Hubs can have a wide variety of ports. Most
level hubs have four or eight ports, but business
level hubs can have 32 or more

A hub provides no cure for the bandwidth
sharing problem of Ethernet networks. if

user put 32 PCs on a 32
port 100 BaseT hub, there is 32 PCs sharing the 100 Mbps
bandwidth. A switch does fix the problem by in essence making each port a separate
Ethernet network. Each PC gets to use the full bandwidth available, because a switch stops
all collisions.

Cheap and centralized, a star bus network does not go down if a cable breaks.



Explain Unshielded Twisted Pair. (8 marks)

UTP cabling is the defined cabling for 10xBaseT and is the predominant cabling
system used today. There are

many different types of twisted pair cabling to choose from,
depending on the needs of the network. Twisted pair cabling consists of AWG 22
26 gauge
wire twisted together into color
coded pairs. These pairs are loosely encased in a common
insulated jacket

CAT Levels:

UTP cables come in categories that define the maximum speed at
which data can be transferred. The major categories (CATs) are as follows:


Standard phone line


Data speeds up to 4Mbps (ISDN and T1


Data speeds up to 16


Data speeds up to 20Mbps


Data speeds up to


Data speeds up to 1Gbps


Data speeds up to 10Gbps

The telecommunication Industry Association/ Electronics Industries Alliance
(TIA/EIA) establishes the UTP categories.


n the network organization. (8 marks)

All NOSs can be broken into the following basic organizational groups;


The client/server solution to all the sharing resources
questions is to take one machine and dedicate it as a resource to be share
d over the network.
This machine will have a dedicated NOS optimized for sharing files. This special OS
includes powerful caching software. It will have extremely high levels of protection and an
organization that permits extensive control of the data. Thi
s machine is called dedicated
server. All of the other machines that use the data are called clients or workstations.

The client/server system dedicates one machine to act as a “server.” Its only function
is to serve up resources to the other machines on t
he network. Only one NOS fits within the
strictest definition of the client/server concept: the popular Novell NetWare.

A NetWare server is not used directly by anyone. That is, a NetWare doesn’t
provide a user environment for running any applications exce
pt for tools and utilities.
Novell NetWare just serves shared resources; it does not run application programs.

Peer to Peer:

Some networks do not require dedicated servers

computer can perform both server and client functions. A peer to peer netwo
rk enables any
or all of the machines on the network to act as a server. Peer to peer networks are much
cheaper than client/server networks.

The biggest limiting factor for peer to peer networking is that it’s simply not
designed for a large number of comp
uters. Windows has a built
in limit to the number of
users. Microsoft recommends that peer to peer workgroups not exceed 15 PCs. Beyond that
a domain makes more senses.

Security is another big weakness of peer to peer networks. Each system on a peer to
r network maintains its own security. It only has three levels of network permissions
from which to choose;




Full Access


Depends on Password

Peer to peer workgroups are little more than a pretty way to organize systems to
make navigation through N
etwork Neighborhood a little easier. In reality, workgroups have
no security value. Still, the networking needs are limited

such as a small home network

peer to peer networking is an easy and cheap solution.



Explain protocols and br
iefly discuss each. (8 marks)

Network protocol software takes the incoming data received by the network card,
keeps it organized, sends it to the application that needs it, and then takes outgoing data
from the application and hands it to the NIC to be sen
t out over the network. All networks
use some protocol. Although many different protocols exist, NetBEUI, IPX/SPX, TCP/IP
and AppleTalk are widely used.


Novell developed the Internetwork Packet Exchange /
Sequenced Packet Exchange (IPX/SPX) proto
col exclusively for their NetWare products.
The IPX/SPX is speedy, works well with routers, and takes up relatively little RAM when
loaded. Microsoft implements a version of IPX/SPX called NWLink.


Transmission Control Protocol/ Internet Protocol (T
was originally developed for the Advanced Research Projects Agency Network
(ARPANET). TCP/IP became the build
in protocol for the popular BSD UNIX, and other
flavors of UNIX quickly adopted it as well. TCP/IP is the best protocol for larger (>200
des) networks. The biggest network of all, the internet, uses TCP/IP as its default
protocol. Windows NT also uses TCP/IP as its default protocol. TCP/IP lacks speed and
takes up a large amount of memory when loaded, but it is robust, well understood, and
universally supported.

Apple Talk

Apple talk is the proprietary Apple Protocol. Similar to IPX, it
is small and relatively fast. The only reason to use an AppleTalk protocol is to communicate
with older Apple computers on a network.



Explain th
e following topics.


Hubs and Switches.


Duplex and Half Duplex.

(a) Hubs and Switches:

In a 10
BaseT network, each PC is connected
to a 10
BaseT hub or switch. To add a device to the network, simply plug another cable into
the hub or switch. 10
BaseT uses

the star bus topology. The hub holds the actual bus and
allows access to the bus through the ports. Using a star bus topology creates a robust
network; the failure of a single PC will not bring down the entire network.































Table: UTP Cabling Color Chart

In a 10xBaseT network, the maximum distance from the hub to any dev
ice is 100
meters. The maximum number of PCs that can be attached to any one hub is 1,024. Most
hubs come with 4,8,16, or 24 ports. 10xBaseT hubs acts as repeaters, amplifying the signals
between devices hooked into the network. They need power to provide
this amplification.

(b) Duplex and Half

All modern NICs can run in full
duplex mode,
meaning they can send and receive data at the same time. The vast majority of NICs and
switches use a feature called auto
sensing to accommodate very old devices

that might
attach to the network and need to run in half
duplex mode. Half
duplex means that the
device can send and receive but not at the same time.

duplex devices are exceedingly rare in modern computers. Some NICs just
can’t handle full
duplex co
mmunication when plugging them directly to another NIC using
a crossover cable, that is, no switch.


Chapter 24

The Internet


Explain MODEMs. (8 marks)

Creating a dial
up network required equipment that could turn digital data into an
analog si
gnal to send it over the telephone line, and then turn it back into digital data when
it reached the other end of the connection. Such device is called a modem. Modems enable
computers to talk to each other via standard commercial telephone lines by conver
analog signals to digital signals, and vice versa. The term “modem” is short for

Telephone wires transfer data via analog signals, that is, continuously changing
voltages on a wire. Computers, being binary by nature, use only tw
o states of voltage; zero
volts and positive volts. Modems take analog signals from telephone lines and turn them
into digital signals that the PC can understand. Modems also take digital signals from the
PC and convert them into analog signals for the out
going telephone line.

A modem is used in serial communications: It transmits data as a series of individual
1’s and 0’s. To proceed parallel communication, transmitting and receiving data in discrete
bit chunks. The individual serial bits of data are con
verted into 8
bit parallel data that the
PC can understand through the Universal Asynchronous Receiver/Transmitter (UART)
chip. There are many types of UARTs, each with different functions. External modems can
convert analog signals to digital ones and vic
e versa, but they must rely on the serial ports to
which they’re connected for the job of converting between serial and parallel data. Internal
modems can handle both jobs because they have their own UART built in.


Explain ISDN. (8 marks)

There are many
pieces to standard telephone connection. First, there’s the phone line
that runs from your phone out to a Network Interface Box, and into a central switch
belonging to the telephone company. These central switches connect to each other through
y trunk lines. Before 1970, the entire phone system was analog; over time,
however, phone companies began to upgrade their trunk lines to digital systems. Today, the
entire telephone system, with the exception of the line from your phone to the central off
is digital.

By adding special equipment, at the central office and the user’s location, phone
companies can now achieve a throughput of up to 64k per line over the same copper wires
already used by telephone lines. This process of sending telephone tr
ansmission across fully
digital lines end
end is called Integrated Services Digital Network (ISDN) services.

ISDN service consists of two types of channels: “Bearer” or “B” channels and
“Delta” or “D” channels. B channels carry data and voice informatio
n at 64 Kbps. Most
providers of ISDN allow the user to choose either one or two B channels. The more
common setup is two B/one D, usually called a Basic Rate Interface (BRI) setup. A BRI
setup uses only one physical line, but each B channels send 64K, doub
ling the throughput
total to 128K, doubling the throughput total to 128K. ISDN also connects much faster than



Explain briefly on PPP and DSL. (8 marks)


up links to the Internet have their own special hardware
protocol called

Point Protocol (PPP). PPP is a streaming protocol developed
especially for dial
up Internet access. To Windows, a modem is nothing more than a special
type of network adapter. Modems will have their own configuration entry in the Network
ons applet.

Modems also have a second set of settings in Dial
up Networking on a Windows 9x
systems. These properties are accessed from three windows the main Properties window,
the Server Types window and the TCP/IP Settings window.

To troubleshoot user e
rrors, use the modem’s properties to make sure the volume is
turned up. Have the user listen to the dial tone from the connection. If it doesn’t, make sure
the modem’s line is plugged into a good phone jack. Does the modem dial and then hear
someone saying

“Hello? Hello?” if so, the user probably dialed the wrong number and if so
try the correct number.


Digital Subscriber Line (DSL) connections to ISPs use a
standard telephone line but special equipment on each end to create always
on Internet
tions at blindingly fast speeds, especially when compared with analog dial
connections. The two most common forms of DSL are asynchronous (ADSL) and
synchronous (SDSL). ADSL provides 128, 256 or 384 Kbps up load speed and usually
2Mbps download speed. S
DSL provides the same upload and download speed. DSL
requires very little setup from a user standpoint.



Explain the following topics.





(a) Satellite

Satellite connections to the Internet get the data
beamed to a satellite

dish on your house or office; a receiver handles the flow of data,
eventually sending it through an Ethernet cable to the NIC in your PC. The early days of
satellite required to connect via a modem. The user would upload at the slow 26 to 48 Kbps
modem sp
eed, but then get superfast downloads from the dish. Newer technology still
requires the initial setup be done via modem, but the download and the upload go through
the dish.

Satellite might be the most intriguing of all the technologies used to connect to

Internet today. As with satellite television, trough, the user need to have the satellite dish
point at the satellites and the signal will degrade in foul weather such as rain and snow.


The various wireless networking technologies out
here today don’t fulfill that dream yet. When they work, it’s like magic. Connecting to the
Internet via wireless means that you must connect to a LAN that’s wired to an ISP. The
local Internet café purchases high
speed Internet service from the cable or t
elecom company
and then connects a wireless access point (WAP) to its network. When the user walk in with
his portable PC with wireless NIC and open a web browser, the wireless NIC communicates
with the full wired DHCP server via the WAP and the user is su
rfing on the Internet.