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PROJECT REPORT
ON COMPUTER HARDWARE AND NETWORKING
ACCOMPLISHED AT MASS INFOTECH (CEDTI) , YAMUNA NAGAR
(HARIYANA)
SUBMITTED IN PARTIAL FULFILLMENT OF BACHELOR OF ENGINEERING
(COMPUTER ENGG. DEPT.) ,
2004
UNDERTAKEN BY:- SUBMITTED TO:- PANKAJ ACHARYA HEAD COMPUTER
ENGG. TRAINING & PLACEMENT CELL "POORNIMA COLLEGE OF
ENGINEERING"
JAIPUR
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ACKNOWLEDGEMENT
" MASS INFOTECH " is affillited by CENTER FOR ELECTRONICS DESIGN
AND TECHNOLOGY OF INDIA(CEDTI). Govt. of India, Ministry of
Information Technology. This certificate was acquried in 1997 for
hardware and networking.Even though for a very short span, to be
able to work in" Mass infotech " has been a valuable experience in
the practical education and has given me a priceless insight into
the functioning of a team of technology in aproven productive
environment. I here by present my sincere thanks to all the
concerned authorities for helping me in completing the training . I
am glad to thank "Mr. Rajiv Lamba" who gave me this golden chance
to gain knowledge at their basestation. I also extend my heartiest
thanks to all the engineers and faculty members for sparing their
valuable time in guiding me through my training. In short I would
like to thank all the staff members of "Mass Infotech" for their
co-operation and healthy support.
PANKAJ ACHARYA
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PREFACE
Today is the world of technology. There will be 5 crore
computers and 10 crore mobile phones in the country by the end of
the year 2008, bringing plethora of related job opportunities in
manufacturing, services and maintenance in this arena of
technology.
As an engineering graduate, innumerable career options are
available for you in varied fields but you will definitely agree
that technical careers offers not only good remuneration and growth
prospects but social status and job satisfaction too. Therefore
apart from the engineering degree, which is more or less
theoretical in nature you are required to undertake practical
training, which can give you an edge over others when you apply for
the vacancies in the organizations.
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CONTENTS
1) HARDWARE
a) Introduction of hardware.
2) INSIDE THE SYSTEM BOX. a) Center processing unit. b) Memory.
c) Mother board/Electronic circuit board. d) Secondary storage
devices. e) Different types of connector. f) Different types of
cards
. 3)POWER
a) SMPS. b) UPS
4)NETWORKING a) Introduction to networking. b) Types of
networking. c) Topologies.
5)NETWORK DEVICES a) Hub, switch, router. b) Ccommunication
channel. c) Cbles and connector.
6)RULES OF NETWORK a) Layers architecture. b) Protocol. c) Ip
addressing. d) Network model.
7) CONNECTIVITY a) Workgroup network using WINDOWS XP b) Domain
networking using WINDOWS 2000 SERVER & WINDOWS XP
8) FUTURE OF NETWORKING.
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COMPUTER HARDWARE:- The Indian hardware industry is expected to
reach a size of USD 62 BILLION by 2010, 12 times its existing size,
with the domestic market accounting for USD 37 billion and exports
for another USD 25 billion. The factors that would bring such mega
growth are:
1. The government has taken aggressive steps in providing
quality infrastructure with Hardware Parks flexible labor policies,
availability of skilled workers, congenial business environment,
level playing field, right policies and incentives, concessional
import duty, reduction in excise duty, customs, SAD, CVD and sales
tax. All these factors will make the market respond positively,
economics of scale will come into play and big hardware companies
will be attracted to set up local manufacturing units. That would
result in high demand of computer hardware and subsequently prices
would come down and make it affordable for a general customer. 2.
Another major segment is SCHOOLS & COLLEGES. According to cll,
if 20
PCs are installed in each of the countrys 9, 00,000 schools, the
immediate demand would be 18 million, 10 times the current market
figure.
3. Increase in the use of IT technologies in the governments
interface with the public
has also stimulated the demand for computer hardware.
Migration from the old manual system to computing is taking
place in large portion of government public interaction, especially
in providing statutory services such as land records, property
transactions, authentication services, dealings of publicly owned
utilities, collections of variety of taxes and transportation
(Railways, Roadways and Airways etc). it will lead to a phenomenal
demand for increase in hardware and would provide a big boost to
the sagging national economy.
Central processing unit
There are many vendor of the cpu in the market same of them are
Intel, AMD, VIA/CYRIX, Transumeta / Motorola but the most popular
are Intel and AMD Athelon. The X86 CPU architecture invented by
Intel is the most popular for desktop computers today all the
computers run the windows_9X operating system use X86 CPU
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Intel corporation manufactured various kind of CPUs but in
market the most selling CPU we are concerning. P-3 , Celeron and
P-4 Celeron processor is a substitution of P-3 having same
performance so Celeron is taking place of P-3. When P-4 came the
total architecture is different from P-3. P-3 has 0.18 micron
technology and the P-4 has 0.13 micron technology. P-4 if focused
on multimedia, multitasking, multithreading. This gives batter
performance in gaming, internet computing speed. SYNTAX FOR CPU
RECOGNITION Name speed in MHz/cache (KB)/FSB e.g. --- Intel Pentium
3 1133/256/100 CACHE MEMORY OF CPU This is a memory associated with
CPU, and often the motherboard. This is a type of memory thats used
to hold a duplicate of a larger store. This is faster than the main
memory .By placing the most often accessed data in the cache
memory, overall system speed increases. Type of cache memory.
(1) L1 cache (2) L2 cache
L1 CACHE MEMORY (LEVEL 1 CACHE) This is closet to the CPU is the
level 1 or L1 since 80486 an L1 cache has been built in to the CPU
itself. This cache run at the CPUs internal speed and so is very
fast.
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Celeron ---------- L1 cache is 16KB+16KB Pentium 3 ------- L1
cache is 16KB+16KB AMD athlon----- L1 cache is 128KB Since L1 cache
is part of the CPU it cant be expanded or replaced. L2 CACHE MEMORY
(LEVEL 2 CACHES) A L2 cache is more copious than an L1 cache, but
its also slower. For CPU after Pentium Processor this is coated on
the CPU package. CPU L2 CACHE SIZE PENTIUM-3 256-512KB CELERON
0-128KB AMD ATHLON 512KB Placing the L2 cache on the CPU module
improves performance relative to putting it on the motherboard
largely because the cache can operate at a faster speed. FSB (FRONT
SIDE BUS)/ CPU BUS Modern CPUS run at two separate speeds: the core
speed and the bus speed. The core speed is the no. associate most
strongly with the CPU and is the speed at which most of CPU
circuitry runs. The bus speed is the speed of interface between CPU
and the motherboard. Now a days bus speed range from 66 MHz To
theoretical maximum of 400 MHz for slot A.(Main socket). In order
to set the CPU core speed motherboard includes jumpers or BIOS
settings to specify a clock multiplier. The CPU runs its core at
the bus speed multiplied by the clock multiplier. E.g. 113.3MHz bus
speed with a 10X clock gives CPU speed 1133 MHz(core speed). CPU
VOLTAGE +Vcc supply to CPU is +5v and V core = 1.7 v. As the CPU
speed increases it becomes desirable to reduce the CPU voltage. In
order to reduce the heat buildup inside the chips. For cooling a
heat sink fan is mounted on the CPU.
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MEMORY.
IDEA BEHIND BIOS ROM-BIOS It is short form for read only memory
-basic input output
system. The ROM-BIOS is a set of Program built into the computer
ROM memory that Provides the most basic, low level and intimate
control And supervision operation for the computer.
=>The task of the bios is to take care of the immediate needs
of the hardware and to isolate all other programs from the details
of how the hardware works.
=>fundamentally the bios is an interface a connection and a
Translator between the computer hardware and the software
Programs.
PARTS OF BIOS There are three main part of the ROM-bios program.
First part:- This part is used only when the computer is first
turned ON;
these are Test and Initialization program that check to see that
the computer is working. The delay between powering on the computer
and The moment when it start working for you is due to running of
these test and initialization program which sometimes are Called
the POWER ON SELF TEST (POST).
Second part:- Important parts of the bios are its
routimes.These
programs provides the detailed and intimate control of The
various part of the computer, particularly for the input/output
Peripherals, such as the disk drives.
Third part:- Rom-bios are the boot strap loader program. Basic
content of bios: Standard CMOS feature. Advanced bios feature.
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Advanced chipset feature. Integrated peripherals. Power
management setup. PnP /PCI configuration. Pc health status.
Frequency/voltage control. Load optimized default. Set supervisor
password. Set user password. Save & exit setup. Exit without
saving.
Booting:- The time duration between the appearance of the dos
prompt or any window and the switch on the power supply the whole
process is known as the booting process. TYPE OF BOOTING A) COLD
BOOTING B) WARM BOOTING COLD BOOTING:- When we switch off the
computer completely and properly after some
time we start Computer again is known as the cold booting. WARM
BOOTING:- When we restart the computer from the restart button or
using the key by
simply pressing them i.e. ctrl+alt+del key is known as warm
Booting. MINIMUM REQUIREMENT FOR BOOTING: For booting we required
minimum three files- 1) ms_dos.sys 2) io.sys 3) Command.com In
these files first two files are hidden files and the third one is
normal file.
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MOTHERBOARD If the CPU is the heart of the system the
motherboard is its circulatory system. The CPU has to be fitted on
the socket on the Board. The board has input output ports, ram, PCI
slots, IDE port, chipset, Power connector, AGP slot, other
expansion slots, floppy port. The key features of the motherboard.
1. Socket 2. memory support 3. expansion slots 4. onboard IDE
channels 5. Power supply and Power management 6. chipset 7. BIOS 8.
Battery 9. Input/output ports.
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SECONDARY STORAGE DEVICE
HARD DISK DRIVE Hard disk are thin but rigid metal platters
covered with a substances That allows data to be held in the form
of magnetized spots. Hard disk are Tightly sealed within an
enclosed hard disk drive unit to prevent any foreign Matter from
getting inside Data may be recorded on both sides of the disk
Platters. These platters are made of either using glass or
aluminum.
A head crash happens when the surface of the read write head or
particles on its surface come into contact within the surface of
the hard disk platter, causing the loss of some or all of the data
on the disk. Both EIDE(enhanced integrated device electronics) and
SCSI(small computer System interface) disks suffer from the limit
of 1024 cylinder. The difficulty is that the old CHS
(cylinder/head/sector) addressing mode uses a 10 bit number can
hold a value of between 0 and 1023 , So the number of cylinders
accessible by the BIOS is limited to 1024 hard disk performance
measurements are-
(1) disk head seek time (2) data transfer rate (3) disks cache
size.
Disk head seek time Time taken to seek the data by move the head
is referred as the seek time. The seek Time measurement thats most
often used is the average seek time, which is
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the average time move the head from one location to a randomly
selected other location.
Another measurement closely related to seek time involves a
second component beyond the head movement latency Latency is the
time it takes the desired sector to come up under the read/write
head after a seek operation and average out to half the time it
takes for a rotation of the disk platter. The combination of seek
time and latency is known as access time. Seek time, latency , and
access lime are all measured in milliseconds. Seek time of 5ms-10ms
and spin at 5400 and 10000 Rpm( lower latencies being associated
with higher spin rates.) DISK TRANSFER RATE
This simply means how quickly the disk can transfer data to and
from the computer. The disk spins at the same rate no matter what
cylinder is being read, but modern hard drive design place more
sectors along outer cylinder than along inner ones. This means that
data read from the outer cylinder transfer faster than to data read
from inner cylinders. Hence the internal data rate is variable.
DISK SPIN RATE The faster a hard disk spins, the faster it can
transfer data for this reason manufactures speed up spin rate now a
days 10000 rpm hard disk an popular
7,200 rpm HDD - Baracuda hard disk
10,000 rpm HDD - Cheetah hard disk
A drive with fewer cylinders but more sectors per cylinder
faster than one with more cylinders and fewer sectors per cylinder,
all other things being equal. HEAT GENERATION AND DISSIPATION.
As hard drives have spun faster they are developed increasing
problems with heat. The faster spin rate produce increased heat and
from friction and from the increased demands placed on electronic
circuits that process the data. The most common method of providing
extra cooling to extra hot drives cooling fan to your system. These
device mount in a 5.25 Inch drive bay and allow to mount a 3.5 inch
drive within adapter rails the front bezel incorporates two or
three small fans that blow air onto the hard disk. DISK CACHE
SIZE
All modern hard drives incorporate a disk cache typically
between 512kb and 2mb in size. This cache is composed of RAM chips.
Most Operating systems including LINUX maintain their own disk
Cache in computers RAM this is more faster. In case of LINUX the
disk cache can grow and shrink as necessary.
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FLOPPY DISK DRIVE
A floppy disk drive is a storage device that stores data on
removable 3.5inch diameter diskettes These are encased in hard
plastic but the mylar disk inside flexible or floppy Each can store
1.44 million Bytes(characters) or more of data. Floppy disk have a
Write protect notch which allows you to prevent a diskette from
being written to. On the diskette data is recorded in concentrics
circres called tracks.
OPTICAL DISKS: CDs AND DVDs
An optical disk is a removable disk, usually 4.75 inches in
diameter and less than one twentieth of an inch thick on which data
is written and read through the use of laser beams.To read the
data, a low power laser light seams the disk surface: pitted areas
are not reflected and are interpreted as 0 bits, smooth areas are
reflected and are interpreted as 1 bits. (1) CD-ROM(Compact disc
read only memoly)
It only reads a CD and cannot after its contents A CD-ROM disk
capacity is 650 mb -750mb the speed of a cd is read in x eg.52x ,
which menas -> 1x=150 kb/s of transfer rate, so 44x gives 6600
kb persecond.
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(2)CD-R(Compact disk recordable) The disk can be written once
but can be read many times. (3)CD-RW(compact disk rewritable)
This is an erasable optical disk allows user to record and erase
data so that the disk can be used over and over again CD-RW disks
can not be read by CD-ROM. CONNECTORS:
(1)keyboard connector (2) mouse connector (3) usb connector
(4)serial port connector (5)power supply connector (6)ATX connector
(7)AT and baby AT connector (8)fan connector (9)vcore connector
(10)cd audio jack connector
USB Connector
Universal serial bus is the latest craze in external device
connector It is faster than Rs-232 serial Most importantly, all the
USB devices attached to a computer(up to 127) consume a single
interrupt(IRQ). If we have other USB
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devices such as a USB digital camera or modem we might able to
save an interrupt by rutting mouse on the USB port as well .
When computer Boot up IRQ is reserved for all the peripherals
connected
to board but in case of the mouse or some other device is
connected to the port than its driver will not be loaded and after
starting operating system the connecting of mouse will not work but
for the USB port whether the drive is connected or not the IRQ is
reserved so that whenever we want to attach USB Camera it does not
bother.
Serial port connector
Conventionally serial ports more properly referred to as RS-232
These are mostly used to attach x86 computers modern computers use
9-pin serial port connectors generally that are used for mouse and
connected at COM port m/b have 2 com ports COM 1 and COM 2 These
days mouse port come separately and COM port are used for other
devices to communicate. power supply connector Generally it has 4
wires for power conduction .these are plugged into the device in
only one way .3.5 inch floppy use smaller connectors. Power
splitter is used to split the power to connect more devices. One or
two splitter probably does not constitute problem.
The connector has 4 wires. (a)Red +5v DC (b)Black GND (c)Black
GND
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(d)Yellow +12v DC
ATX Connector
At is the newer version of AT/Baby AT. ATX motherboard use a
single keyed power connector in contrast to the dual connectors
of AT and Baby AT boards. The keyed ATX power connector makes it
nearly impossible to destroy a motherboard by connecting power
supply incorrectly. In addition ,ATX boards run on 3.3v eliminating
the need of voltage regulator.
ATX boards also host a series of power related changes, allowing
the computer to power itself off when the o.s. shuts down power
itself on in response to specified events, go into low power mode
and so on .
These are of 4 types-
(a)ATX (b)Mini-ATX (c)Micro-ATX (d)Flex-ATX
AT and Baby AT connectors
This kind of connectors are used in small system like laptop and
small cabinets this was used before ATX come for home
uses.Generally they have 5-pin
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DIN connector. AT and Baby AT motherboards used a pair of power
connector, which had
to be attached to the cases power supply via cables permanently
attached to the power supply in such case M/B voltage is 5v.
But todays motherboard required 3.3v.so such m/B required
voltage
regulators which converts 5v to 3.3v these voltage regulators
produced heat and depending upon the amount of current drawn by the
CPU could overheat and cause unreliable operation.
FAN Connector
CPU cooling FAN, system FAN has required power supply to move
fan .these have 3 pin connector inserted at motherboard at
particular place.
V-core Connector In some m/B there is no provision for
internally give voltage to CPU like
new boards. They have this connector which is key locked to m/B
and give required voltage to CPU.
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CD audio jack Connector. This connector has double ended. One
inserted into CDROM drive and
other end is connected to CD IN near the sound chip on
motherboard. This is used in case of running audio CD without as
interface.
Different types of cards
There are of seven types of cards- (1)DISPLAY CARD (a)
CGA->
color graphical adaptor This is of 9 pin card. 8088,80286,80386
8bit isa slot
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(b) VGA->
video graphical adaptor 15 pin cards. m/b 80486,PI
16bit/32bit/64bit.
(c) Dual CGA card-> 9pin+25pin 9pin->monitor
25pin->printer 4 MB in size
(2)IDE CARD [integrated device electronics]
16 bit cards. These cards are used for H.D.D and F.D.D
control.
(3)SIDE CARD [super integrated device electronics]
F.D.C/H.D.C/MOUSE/PRINTER/GAME CONTROLLER 16bit/32bit
Com1->mouse Com2->external modem[10 pin]
(4)SOUND CARD (a) non-pci->
16bit/32bit (b) pci->
64bit in this card there is a 15 pin game controller and au
out
,mic,Line in 4 MB in size
(5)NETWORK CARD (LAN card)
(a) 32bit LAN card Speed is 10 MBits/s. There two types of
connectors used.
BNC->Broadcast network connector RJ->Register jack
connector(RJ->45)
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Boot rom->it is an IC used to boot all the other pcs which
has no hard disk but they can be boot with the help of network boot
this process is done by the help of Boot rom.
b) 64 bit LAN card,
Speed is 100Mb.
(6)MODEM.
Convert analog signal into digital signal and vice versa.
There are two types of modem. a) External Modem.
Speed of the modem card 24/28/33/40/50/56.6Kbps
b) Internal Modem.
Having same speed as external card .it is also PCI Card
(64bit).its speed which is now a day used is 56.6Kbps.
(7)TV-TUNNER CARD
It is also a PCI card of 64 bit. it is two types
(a) Internal (b)External
POWER SUPPLY Most of the cases come with power supplies. Each
variety of case -ATX, AT tower. It is possible to overload a power
supply but power splitter. Since we know WATTS=VOLTS*AMPS
Capacity of power supply measures in wattage. eg. if a 5v device
draws 10 amps, it consumes 50 watts. As an example a computer with
one 15a card, two PC cards, a 3.5 inch floppy disk ,two HDD, a
cd-rom and two extra cooling fan.
Adding up these values, this computer requires 50.16w from 3.3v,
77.5w
from 5v and 70.5w from 12v for a total of 198.16w. The
motherboard consumes a
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few more watts, as well perhaps 25w or so depending on the board
and cpu. Not all devices require their max. amounts of power at the
same time. Typically for instance, harddisk require a great deal of
power when they start up to over come the inertia inherent in
stopped disk platters.
WIRES IN POWER SUPPLY
The green wire, it present is a grounding wire. Attach it to any
convenient metal part of the case.
The black and white wires connect to the angled tabs on (toggle)
the power switch.
The brown and blue wires connect to the tabs that are parallel
to one another on the switch. The brown and blue wires always carry
current when the power supply is plugged in. Therefore, we should
only try to connect or disconnect these wires ofter unplugging.
SWITCH MODE POWER SUPPLY(SMPS)
It is the power supply system used in the system box. The switch
mode
power supply(SMPS) is use 220v as the input and at the out it
gives DC current with different values used by different component
of the computer as +5v used by keyboard LED , +12v used by SMPS
cooling fan and +12v for processor cooling fan. The out put power
supply so we get form the SMPS while using the different type of
color. They are basically of six color.
Different color wire from SMPS with the voltage they have-
yellow ----------->+12v red ------------>+5v black
------------>GND blue ------------>-12v white
------------>-5v orange------------->power signal identify We
have two type of the SMPS cabinate- ATX--->Advance Technology
Exchange AT ---->Advance Technology
ATX cabinate has ATX SMPS have 20 pin with lock system.
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AT cabinate has AT SMPS have 12 pin with center wire black
color.
UNINTRRUPTIBLE POWER SUPPLY It is an device which is used to
store the elecric power when the main
power supply is cut off by any reasion. Then we can use the
power of the ups which is allready store in the UPS. It basically
contain the storage battery which
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store the power supply. It take 220v as the input and gave 220v
as the output. It also contain the transformer used to step up the
electricity.
NETWORKING
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INTRODUCTION
A computer network is group of computers that are connected
together to
share resources, such as hardware, data, and/or Software. It is
a data communication system that interconnects computer Systems at
different sites. Networking is a collection of individual networks,
connected by Intermediate Working devices that function as a single
large network. Industries, colleges & many business
organizations use internetworking. For many purpose such as fast
communications internally, sharing a device for many computers and
for many other purposes also.
HISTORY & CHALLENGES of NETWORKING The first networks were
timesharing networks that use mainframes and
attached terminals. LAN evolved around PC evaluation. LAN
enabled multiple users in a limited geographical area. Lack of
management and duplication of resources resulted in evolution of
LAN. Challenges were connecting various
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systems together having various Technologies. Making standards
was again a big challenge. Challenges were face in mostly these
areas such as connectivity, reliability, network management &
flexibility. The final concern was related to network expansion
& new technologies.
TYPES OF NETWORKS 1. LAN (local area network) 2. MAN
(metropolitan area network) 3. WAN (wide area network
LOCAL AREA NETWORK
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INTRODUCTION TO LOCAL AREA NETWORK(LAN) A local area network is
a group of computers and associated devices that
share a common Communications line or wireless link and
typically share the resources of a single processor or server
within a small geographic area. Usually, the server has
applications and data storage that are shared in common by multiple
computer users. A local area network may serve as few as two or
three users or as many as thousands of users.
A non-public data Communications network Confined to a
limited
geographic area (usually within a few miles), used to provide
communication between computers and peripherals. The area served
may consist of a single building, a cluster of buildings, or a
campus-type arrangement.
In a typical LAN configuration, one computer is designated as
the file
server. It stores all of the software that controls the network,
as well as the software that can be shared by the computers
attached to the network. Computers Connected to the file server are
called work stations. The workstations can be less powerful than
the file server, and they may have additional software on their
hard drives. cables are used to connect the network interface cards
in each computer.
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OPEN SYSTEM INTERCONNECTION MODEL (OSI)
The International Standards Organization developed a
theoretical model of how networks should behave and how they are
put together. The ISO's model is used through the industry today to
describe various networking issues. This model is called the Open
Standards Interconnect Model.
The Open Systems Interconnection reference model for
describing network protocols was devised by the Internet
Standards Organization. It divides protocols in to seven layers to
standardize and simplify definitions.
SEVEN LAYERS OF OSI MODEL
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1. Application Layer 2. Presentation Layer 3. Session Layer 4.
Transport Layer 5. Network Layer 6. Data-link Layer 7. Physical
Layer
Layer Function
Protocol N/W Device
Application User Interface
used for applications specifically written to run over the
network
allows access to network services that support applications;
directly represents the services that directly support user
applications
handles network access, flow control and error recovery
Example apps are file transfer-mail.
DNS; FTP; TFTP; TELNET; NCP;
Gateway
Present- ation Translation
Translates from application to network format and vice-versa all
different formats from all sources are made into a common uniform
format. Responsible for protocol conversion, character conversion,
data encryption / decryption, data
Gateway
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compression.
Session "syncs and sessions"
establishes, maintains and ends sessions across the network
provides synchronization services by planning check points in the
data stream => if session fails, only data after the most recent
checkpoint need be transmitted manages who can transmit data at a
certain time and for how long
NetBIOS RPC
Gateway
Transport packets; flow control & error-handling
divides streams of data into chunks or packets; the transport
layer of the receiving computer reassembles the message from
packets
provides flow control & error-checking to guarantee
error-free data delivery, with on losses or duplications
provides acknowledgment of successful transmissions; requests
retransmission if some packets dont arrive error-free
TCP, ARP, RARP;
GatewayBrouter
Network
addressing;
routing
translates logical network address and names to their MAC
address responsible for addressing, determining routes for sending
, managing network problem
If router cant send data frame as large as the source computer
sends, the network layer compensates by breaking the data into
smaller units. At the receiving end, the network layer reassembles
the data
IP; ARP; RARP, ICMP; IGMP;
IPX
OSI
Router
ATM Switch
Data Link data frames to bits
Turns packets into raw bits at the receiving end turn bits into
packets.
handles data frames between
Logical Link Control
error correction and
bridge Switch
Hub
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flow control
802.1 OSI Model
802.2 Logical Link Control
the Network and Physical layers
the receiving end packages raw data from the Physical layer into
data frames for delivery to the Network layer
responsible for error-free transfer of frames to other computer
via the Physical Layer
This layer defines the methods used to transmit and receive data
on the network. It consists of the wiring; the devices use to
connect the NIC to thewiring, the signaling involved transmitting /
receiving data.
Media Access Control
NIC
Physical
hardware; raw bit stream
transmits raw bit stream over physical cable
defines cables, cards, and physical aspects
defines NIC attachments to hardware, how cable is attached to
NIC
defines techniques to transfer bit stream to cable .
IEEE 802 IEEE 802.2
ISO 2110
ISDN
Repeater Multiplexer
Hubs
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WORKING OF OSI MODEL
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Components of LAN
(a) Network Cabling (b) Network Devices
(c) Network Topology
SYSTEM -1 SYSTEM -2 COMMUNICATION
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(d) Protocols
What is Network Cabling? Cable is the medium through which
information usually moves from one
network device to another. There are several types of cable
which are commonly used with LANs. In some cases, a network will
utilize only one type of cable, other networks will use a variety
of cable types. The type of cable chosen for a network is related
to the network's topology, protocol, and size. Understanding the
characteristics of different types of cable and how they relate to
other aspects of a network is necessary for the development of a
successful network.
The following sections discuss the types of cables used in
networks and other related topics.
Unshielded Twisted Pair (UTP) Cable Shielded Twisted Pair (STP)
Cable Coaxial Cable Fiber Optic Cable
Unshielded Twisted Pair (UTP) Cable Twisted pair cabling comes
in two varieties: shielded and unshielded.
Unshielded twisted pair (UTP) is the most popular and is
generally the best option for school networks. The quality of UTP
may vary from telephone-grade wire to extremely high-speed cable.
The cable has four pairs of wires inside the jacket. Each pair is
twisted with a different number of twists per inch to help
eliminate interference from adjacent pairs and other electrical
devices. The tighter is the twisting, the higher is supported
transmission rate and the greater the cost per foot. The EIA/TIA
(Electronic Industry Association/Telecommunication Industry
Association) has established standards of UTP and rated five
categories of wire.
Unshielded Twisted Pair Connector The standard connector for
unshielded twisted pair cabling is an RJ-45
connector. This is a plastic connector that looks like a large
telephone-style connector . A slot allows the RJ-45 to be inserted
only one way. RJ stands for Registered Jack, implying that the
connector follows a standard borrowed from
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the telephone industry. This standard designates which wire goes
with each pin inside the connector
Shielded Twisted Pair (STP) Cable A disadvantage of UTP is that
it may be susceptible to radio and electrical
frequency interference. Shielded twisted pair (STP) is suitable
for environments with electrical interference; however, the extra
shielding can make the cables quite bulky. Shielded twisted pair is
often used on networks using Token Ring topology.
Coaxial Cable Coaxial cabling has a single copper conductor at
its center. A plastic layer
provides insulation between the center conductor and a braided
metal shield .The metal shield helps to block any outside
interference from fluorescent lights, motors, and other
computers
Fiberoptics Fiber optics is a system which transmits signals
from one location to another through a thin strand of glass which
carries light pulses to carry data. This transmission system works
on the same principle that copper wires do, but is done in a
different way. Data is encoded from electrical signals into optical
light pulses, sent through a glass medium and converted back and
decoded at the other end. Both copper and optics use electricity at
the end of their lines, but optics uses light in between to carry
the data.
NETWORK DEVICES
INTRODUCTION Network Devices is a machine or component that is
attached to a
computer. Examples of devices include disk drives, printers,
mice, and DSL
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modems. These particular devices fall into the category of
peripheral devices because they are separate from the main
computer.
Most devices, whether peripheral or not, require a program
called a device driver that acts as a translator, converting
general commands from an application into specific commands that
the device understands.
Types of Network Devices: 1. Hub
2. Switch
3. Router
4. Repeater
5. Network card
6. Bridge
7. Gateways
HUB As its name implies, a hub is a center of activity. In more
specific network
terms, a hub, or concentrator, is a common wiring point for
networks that are based around a star topology. Arcnet, 10base-T,
and 10base-F, as well as many other proprietary network topologies,
all rely on the use of hubs to connect different cable runs and to
distribute data across the various segments of a
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network. Hubs basically act as a signal splitter. They take all
of the signals they receive in through one port and redistribute it
out through all ports.
Hub works on Physical Layer of OSI model.
SWITCH
A Switch is a devicethat provides a central connection point for
cables
from workstations, servers, and peripherals. In a star topology,
twisted-pair wire is run from each workstation to a central
switch/hub. Most switches are active, that is they electrically
amplify the signal as it moves from one device to another. Switches
no longer broadcast network packets as hubs did in the past, they
memorize addressing of computers and send the information to the
correct location directly. Switches are:
Usually configured with 8, 12, or 24 RJ-45 ports
Switch works on Data-Link Layer of OSI model.
Often used in a star or star-wired ring topology
Sold with specialized software for port management
Usually installed in a standardized metal rack that also may
store net DSL modems, bridges, or routers
Switches subdivide larger networks and prevent the unnecessary
flow of network traffic from one segment to another, or in the case
of cross-segment traffic, switches direct the frames only across
the segments containing the source and destination hosts.
This ensures the integrity of our data; it does nothing to
increase overall network speed. Switches help to ensure additional
network access opportunities for attached devices (increasing speed
and reducing traffic) by restricting data flows to local segments
unless frames are destined for a host located on another segment.
The switch examine the destination address and forward the
requisite frames only across the destination segment, leaving all
additional segments attached to that switch free from that
particular broadcast and (theoretically) able to facilitate
local-segment traffic. Rather than being a passive connection
between multiple segments, the switch works to ensure that network
traffic burdens the fewest number of segments POSSIBLE.
Difference between a hub and a switch
Hubs and switches are different types of network equipment that
connect devices. They differ in the way that they pass on the
network traffic that they
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receive. Switches differ in some ways. They can be of the
store-and-forward type, storing each incoming packet in an internal
buffer before forwarding it, or cut-through, beginning to forward
packets already after their header is in and before the rest of the
packet has been received. Hubs repeat everything they receive and
can be used to extend the network. However, this can result in a
lot of unnecessary traffic being sent to all devices on the
network. Hubs pass on traffic to the network regardless of the
intended destination.
In a small network (less than 30 users), a hub (or collection of
hubs) can easily cope with the network traffic generated and is the
ideal piece of equipment to use for connecting the users.
When the network gets larger (about 50 users), you may need to
use a switch to divide the groups of hubs, to cut down the amount
of unnecessary traffic being generated.
Network Interface Cards
The network interface card (NIC) provides the physical
connection between the network and the computer workstation. Most
NICs are internal, with the card fitting into an expansion slot
inside the computer. Some computers, such as Mac Classics, use
external boxes which are attached to a serial port or a SCSI port.
Laptop computers can now be purchased with a network interface card
built-in or with network cards that slip into a PCMCIA slot.
Network interface cards are a major factor in determining the
speed and performance of a network. It is a good idea to use the
fastest network card available for the type of workstation you are
using.
The three most common network interface connections are Ethernet
cards, Local Talk connectors, and Token Ring cards. According to a
International Data Corporation study, Ethernet is the most popular,
followed by Token Ring and Local Talk.
TOPOLOGY
The physical topology of a network refers to the configuration
of cables, computers, and other peripherals. Physical topology
should not be confused with logical topology which is the method
used to pass information between workstations.
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Main Types of Topologies: The following sections discuss the
topologies used in networks .
Linear Bus
Star
Star-Wired Ring
Tree
Linear Bus A linear bus topology consists of a main run of cable
with a terminator at
each end. All nodes (file server, workstations, and peripherals)
are connected to the linear cable. Ethernet and Local Talk networks
use a linear bus topology
Star A star topology is designed with each node (file server,
workstations, and
peripherals) connected directly to a central network hub on a
star network passes through the hub before continuing to its
destination. The hub manages and controls all functions of the
network. It also acts as a repeater for the data flow. This
configuration is common with twisted pair cable & also used
with coaxial cable or fiber optic cable.
Tree A tree topology combines characteristics of linear bus and
star topologies. It consists of groups of star-configured
workstations connected to a linear bus backbone cable.
PROTOCOLS
A protocol is a set of rules that governs the communications
between
computers on a network. These rules include guidelines that
regulate the following characteristics of a network: access method,
allowed topologies, types of cabling, and speed of data
transfer.
The most common protocols are:
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Ethernet
Token ring
FDDI
ATM
IP protocol
TCP protocol
Ethernet The Ethernet protocol is by far the most widely used.
Ethernet uses an
access method called CSMA/CD (Carrier Sense Multiple Access /
Collision Detection). This is a system where each computer listens
to the cable before sending anything through the network. If the
network is clear, the computer will transmit. If some other node is
already transmitting on the cable, the computer will wait and try
again when the line is clear.
Sometimes, two computers attempt to transmit at the same
instant. When this happens a collision occurs. Each computer then
backs off and waits a random amount of time before attempting to
retransmit. With this access method, it is normal to have
collisions. However, the delay caused by collisions and
retransmitting is very small and does not normally effect the speed
of transmission on the network.
The Ethernet protocol allows for linear bus, star, or tree
topologies. Data can be transmitted over twisted pair, coaxial, or
fiber optic cable at a speed of 10 Mbps up to 1000 Mbps.
Fast Ethernet To allow for an increased speed of transmission,
the Ethernet protocol has
developed a new standard that supports 100 Mbps. This is
commonly called Fast Ethernet. Fast Ethernet requires the use of
different, more expensive network hubs and network interface
cards.
Token Ring The Token Ring protocol was developed by IBM in the
mid-1980s. The
access method used involves token-passing. In Token Ring, the
computers are connected so that the signal travels around the
network from one computer to another in a logical ring. A single
electronic token moves around the ring from one computer to the
next. If a computer does not have information to transmit, it
simply passes the token on to the next workstation. If a computer
wishes to transmit and receives an empty token, it attaches data to
the token. The token then
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proceeds around the ring until it comes to the computer for
which the data is meant. At this point, the data is captured by the
receiving computer.
The Token Ring protocol requires a star-wired ring using twisted
pair or fiber optic cable. It can operate at transmission speeds of
4 Mbps or 16 Mbps. Due to the increasing popularity of Ethernet,
the use of Token Ring in school environments has decreased.
IP Addressing The IP addressing scheme is integral to the
process of routing IP data
gram through an internet work. Each IP address has specific
components and follows a basic format. These can be sub divided and
used to create addresses for sub networks. Each host on a TCP/IP
network is assigned a unique 32-bit logical address that is divided
into two main parts: the network number and the host number. The
network number identifies a network and must be assigned by the
Internet Network Information Center (InterNIC) if the network is to
be part of the Internet
IP Address Format
The 32-bit IP address is grouped eight bits at a time, separated
by dots, and represented in decimal format (known as dotted decimal
notation). Each bit in the octet has a binary weight (128, 64, 32,
16, 8, 4, 2, 1). The minimum value for an octet is 0, and the
maximum value for an octet is 255.
IP Subnet Addressing IP networks can be divided into smaller
networks called subnetworks (or
subnets). Subnetting provides the network administrator with
several benefits, including extra flexibility, more efficient use
of network addresses, and the capability to contain broadcast
traffic (a broadcast will not cross a router).
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Subnets are under local administration. A given network address
can be broken up into many subnetworks. For example, 172.16.1.0,
172.16.2.0, 172.16.3.0, and 172.16.4.0 are all subnets within
network 171.16.0.0. (All 0s in the host portion of an address
specifies the entire network.)
IP Subnet Mask A subnet address is created by "borrowing" bits
from the host field and
designating them as the subnet field. The number of borrowed
bits varies and is specified by the subnet mask
Subnet masks use the same format and representation technique as
IP
addresses. The subnet mask, however, has binary 1s in all bits
specifying the network and subnetwork fields, and binary 0s in all
bits specifying the host field. Subnet mask bits should come from
the high-order (left-most) bits of the host field.
Various types of subnet masks for Class B and C subnets
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The default subnet mask for a Class B address that has no
subnetting is 255.255.0.0, while the subnet mask for a Class B
address 171.16.0.0 that specifies eight bits of subnetting is
255.255.255.0. The reason for this is that eight bits of subnetting
or 28 - 2 (1 for the network address and 1 for the broadcast
address) = 254 subnets possible, with 28 - 2 = 254 hosts per
subnet.
The subnet mask for a Class C address 192.168.2.0 that specifies
five bits of subnetting is 255.255.255.248.With five bits available
for subnetting
25 - 2 = 30 subnets possible, with 23 - 2 = 6 hosts per subnet.
The reference
charts shown in table 30-2 and table 30-3 can be used when
planning Class B and C networks to determine the required number of
subnets and hosts, and the appropriate subnet mask.
How Subnet Masks are Used to Determine the Network Number
The router performs a set process to determine the network (or
more specifically, the subnetwork) address. First, the router
extracts the IP destination address from the incoming packet and
retrieves the internal subnet mask.
It then performs a logical AND operation to obtain the network
number. This causes the host portion of the IP destination address
to be removed, while the destination network number remains.
The router then looks up the destination network number and
matches it with an outgoing interface. Finally, it forwards the
frame to the destination IP address. Specifics regarding the
logical AND operation are discussed in the following section
CASE STUDY
Our aim was to establish a LAB of e-learning for the students of
MASS
INFOTECH through wire networking.
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We were given :
Ten computer Ten 3com LAN card Twenty two RJ 45 connectors UTP
cable One 12 port switch One multimeter Screwdriver Windows 98cd
Crimping tool
What we have done :
Analyzing the Location we saw the location of the lab where we
have to connect the
system in network. As the networking here was in structured form
so we have to keep in view that every thing done should be in
structured way. Initially we consider following points for the
location
Location for Switch Location of wall mounting Location of power
point Location and sequence of computer
Checking connection of power supply and wall mounting We check
the voltage between earth and neutral with the help of
multimeter which must be less than two Volts . We check the
voltage between phase and neutral with the help of
multimeter which should be 220 Volts. As we use only four wires
for communication in patch chords thus
we connect One ,Two, Three, Six Cables in wall mounting
accordingly making of patch chords We cut the UTP cable as
required. We made the patch chords as per
the lucent standards followed by MASS TNFOTACH.
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The lucent standards is as follows : Orange white Orange Green
white Blue Blue white Green Brown white Brown after that we crimp
the chords with connectors . assembling of system We check the RAM,
CMOS battery and confirm that each and
every system is ready to be assembled.
Installation of network card We plug the network card in PCI bus
and connect the system Start the system, computer will deduct the
new hardware device
Which is 3comm network card? We load the driver of 3COM NIC card
and Microsoft client We loaded TCP/IP protocol
We install TCP/IP protocol & give the IP address to each
computer
as per given .
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We give the IP address to each system as per given Subnet mask
of each of them were of class A i.e. 255.255.0.0 Then we give the
address of DNS server
Then we restart the system and check whether each of the
system
is in network or not (by PING command ) c:/>ping 127.0.0.1
(in DOS prompt) we ping the with server
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RESULT: Each of the system are in network and PINGING with
our
network with no loss
CAREER PROSPECTS IN COMPUTER HARDWARE
1. The work of computer hardware engineerings is to research,
design & develop, supervise manufacture and installation of
computers related equipment and implementing solutions.
2. Another major responsibility of computer hardware engineers
is to integrate advanced microprocessors, chipsets, digital/analog
components and firmware into motherboards, networking adapters and
systems that meet the requirements of leading original Equipment
Manufactures (OEMs) in the industry.
3. Consulting opportunities for computer hardware engineers
would grow as business need help managing, upgrading and
customizing increasingly complex systems. Growth in embedded
systems, a technology that uses computers to control other devices
such as applications or cell phones, also will increase the demand
for computer hardware engineers.
4. In India, apart from being a PC support specialist, with
networking knowledge a hardware engineer can become internet
Engineer and be responsible for managing and maintaining the
networking architecture for an organizations website and Wide Area
Network (wan) connectivity.
5. Another option is that of a network security analyst,
responsible for design, implementation and maintenance of network
and computer security policies.
Computer Hardware Engineers are expected to have favorable
job
opportunities as this field will open the largest number of
doors to fulfilling and high-paying careers.
Thus the hardware industry can be a solution to the unemployment
in the
country as it has the potential of generating a million jobs
every year. All this makes hardware industry an attractive career
option.
CAREER PROSPECTS IN NETWORKING
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Several types of positions exist in networking; each with
different average salaries and long-term potential, and one should
possess a clear understanding of these.
Unfortunately, job titles in networking and in information
technology (IT) generally, often lead to confusion among beginners
and experienced folks alike. Bland, Vague or overly bombastic
titles often fail to describe the actual work assignments of a
person in this field.
The basic job titles one sees for computer networking and
networking-related positions include.
Network administrator Network administrator is responsible for
analysis, installation and
configuration of company networks. Daily activities include
monitoring network performance, troubleshooting problems and
maintaining network security.
Network(system) Engineer Network engineers focus primarily on
system upgrade, evaluating
vendor products, security testing, and so on. Network(service)
Technician Network technician tends to focus more on the setup,
troubleshooting and repair of specific hardware and software
products. Service technicians in particular often travel to remote
customer sites to perform field upgrades and support.
Network Programmer/Analyst They generally write scripts that aid
in network analysis, such as
diagnostics or monitoring utilities. They also specialize in
evaluating third party products and integrating new
software/hardware technologies into an existing network environment
or to build a new environment.
Network/Information Systems Manager They supervise the work of
administrators, engineers, technicals
and programmers. Network/information systems managers also focus
own longer-range planning and stragracy considerations.
Network Security Analyst The work of the security analyst is
basically confined to the security
solutions in large networks. They basically check the
unauthorized of the network by any external user.
OCCUPATIONS IN THE INDUSTRY Computer Support Specialist
Electrical & Electronics Engineers
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Electrical and Electronic Engineering Technicians First-line
supervisors/managers of mechanics, installers and
repairer Telecommunications equipment installers and repairers,
except
line installers Electrical power-line installers and repairers
Telecommunications line installers and repairers About 12 percent
of the industrys employees are professional
workers. Many of these are specific and technical personnel such
as engineers and computer specialist. Engineers plan cable routes,
central office and PBX equipment installations, and the expansions
of existing structures, and solve other engineering problems. Some
engineers also engage in research and development of new equipment.
Specializing in telecommunications design voice and data
communications systems, and integrate communications equipment with
computer networks. They have closely with clients, who may not
understand sophisticated communications systems, and design systems
that meet their customers needs. Network systems and data
communications analyst design, develop, test and debug software
products. These include computer-assisted engineering programs for
schematic cabling projects; modeling programs for cellular and
schematic cabling project; modeling programs for cellular and
satellite systems; and programs for telephone options, such as
voice mail, electronic mail, and call waiting. Televommunicatons
specialist coordinate the installations of these systems and may
provide follow-up maintains and training
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HISTORY & CHALLENGES of NETWORKING TYPES OF NETWORKS
What is Network Cabling? Unshielded Twisted Pair (UTP) Cable
Unshielded Twisted Pair Connector
Shielded Twisted Pair (STP) Cable Coaxial Cable Difference
between a hub and a switchHubs and switches are different types of
network equipment that connect devices. They differ in the way that
they pass on the network traffic that they receive. Switches differ
in some ways. They can be of the store-and-forward type, storing
each incoming packet in an internal buffer before forwarding it, or
cut-through, beginning to forward packets already after their
header is in and before the rest of the packet has been received.
Hubs repeat everything they receive and can be used to extend the
network. However, this can result in a lot of unnecessary traffic
being sent to all devices on the network. Hubs pass on traffic to
the network regardless of the intended destination. Network
Interface Cards Main Types of Topologies: Linear Bus Star A star
topology is designed with each node (file server, workstations, and
peripherals) connected directly to a central network hub on a star
network passes through the hub before continuing to its
destination. The hub manages and controls all functions of the
network. It also acts as a repeater for the data flow. This
configuration is common with twisted pair cable & also used
with coaxial cable or fiber optic cable. Tree A tree topology
combines characteristics of linear bus and star topologies. It
consists of groups of star-configured workstations connected to a
linear bus backbone cable. Ethernet Fast Ethernet
Token Ring IP Addressing IP Address FormatThe 32-bit IP address
is grouped eight bits at a time, separated by dots, and represented
in decimal format (known as dotted decimal notation). Each bit in
the octet has a binary weight (128, 64, 32, 16, 8, 4, 2, 1). The
minimum value for an octet is 0, and the maximum value for an octet
is 255. IP Subnet Addressing IP Subnet Mask How Subnet Masks are
Used to Determine the Network Number