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PRACTICAL: 1
INTRODUCTION TO COMPUTER HARDWARE
COMPUTER HARDWARE :
Hardware is the term used to describe the tangible parts of your computer system. This includes
all of the devices, both internal and external, that connect to your computer so that it can perform
all sorts of operations.
Central Processing Unit (CPU)
The Central Processing Unit (CPU), also called a microprocessor, or simply a processor. It is
located on the motherboard and is an integrated circuit that contains millions and millions of
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transistors and other electrical components.
Functions of the CPU:
CPU performs a series of computations to carry out tasks. The Arithmetic/Logic Unit (ALU) is
the part of the central processing unit that performs various calculations and comparisons. Some
basic operations like addition, subtraction, multiplication, and division. Whenever the CPU
wants to access a certain piece of data, the address bus will send the address to the memory, and
the data bus, will receive the data from the memory. Another of the CPU's basic functions is that
it can make certain decisions about how the computer is operated, and based on these decisions,
the CPU can jump from one instruction to another. The CPU also has a pipelining technology
that allows it to perform many different instructions simultaneously.
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Parts of the CPU:
1. Control Unit (CU):
The control unit supervises all of the CPU's operations. It fetches the software instructions from
the memory, and it also coordinates the times and order in which the instructions are carried out.
2. Arithmetic/Logic Unit (ALU):
The arithmetic/logic unit is the part of the CPU that does the actual computing. Data is brought
here, where it is operated on. The ALU can perform both arithmetic and logical operations.
3. Registers:
Registers are special storage locations located inside the CPU. The data contained here can be
accessed much quicker than the data contained in other memory locations, such as the RAM
(random-access memory) and the ROM (read-only memory). Registers in different parts of the
CPU are used for different functions.
4. Memory:
Memories are one of the most important parts of a computer system. The term memory refers to
any device that can be used for storage. There are two basic ways to store memory. One way is
to store the memory within the actual circuitry of the computer, which allows for it to be quickly
accessed by the central processing unit. These memory devices are generally used for temporary
storage of data and programs that are currently used by the CPU. The second type of memory
storage is to store the memory in external storage devices. They include hard drives , floppy
disks, and CD-ROMs.
Types of Memories:
1. Random-Access Memory
Random-access memory, or RAM,is a temporary storage place where your computer holds files
and data that you are using at the present moment.
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2. Read-Only Memory
Read- only memory, or ROM, stores permanent information. The data stored here can not be
altered or changed in any way
3. Caches:
Caches are extremely fast, temporary memories. Sometimes, they are even located right within
the CPU for extra-quick data retrieval!
4. Virtual Memory:
Virtual memory is a special memory that lets your computer handle many programs and
applications with only a small amount of RAM
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Motherboard:
The motherboard is a very integral part of your computer system. The motherboard contains a
complex array of circuits, chips, and wires. It is here that the most vital part of your computer
system are located. Located on the motherboard are the:
1. Central Processing Unit (CPU)
2. Memory
3. System BIOs
4. System Bus
Motherboards come in different sizes and shapes. Form factor is a term that relates to the
physical shape and size of a motherboard. Two motherboards can have essentially the same
components, but these parts can be arranged differently. Thus, the two motherboards would have
different form factors. This section describes some of the more popular motherboard form
factors.
AT/Baby AT
TX/Mini ATX
LPX/Mini LPX
NLX
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DIFFERENT STORAGE DEVICES:
1. Magnetic Disk:
A magnetic disk's medium contains iron particles, which can be polarized—given a magnetic
charge-in one of two directions.Each particle's direction represents a 1 (on) or 0 (off),
representing each bit of data that the CPU can recognize. A disk drive uses read/write heads
containing electromagnets to create magnetic charges on the medium.
2. Hard disk:
Data is stored by magnetising the surface of flat, circular plates called platters which have a
surface that can be magnetized. They constantly rotate at very high speed. A read/write head
floats on a cushion of air a fraction of a millimeter above the surface of the disc. The drive is
inside a sealed unit because even a speck of dust could cause the heads to crash
3. Floppy disk:
In 1969 the first floppy disk was introduced. It was a read only 8 inch disk that could store 80kB
of data. 4 years later, in 1973, the a similar floppy disk with the same size could store 256kB of
data plus it was possible to write new data again and again. Since then the trend has been the
same smaller floppy disks that could store more data. In the late 1990s you could get ahold of 3
inch disks that could store 250 MB of data. These can be found on most microcomputers and
accept the usual 3.5 inch floppy discs. High density discs for a PC hold 1.44 MB of data (enough
to store about 350 pages of A4 text). A floppy disc needs to be formatted before it can be used
but most discs are now sold already formatted for PC's.
4. Magnetic Tape:
Magnetic tape is a medium for magnetic recording generally consisting of a thin magnetizable
coating on a long and narrow strip of plastic. Nearly all recording tape is of this type, whether
used for recording audio or video or for computer storage.
5. CD -Rom:
CD-ROM - means Compact Disc - Read Only Memory. This means you can only read from the
disc, not write or store data onto it. They are also known as optical discs because the data is read
by a laser beam reflecting or not reflecting from the disc surface.
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Like a floppy disc, a CD-ROM only starts spinning when requested and it has to spin up to the
correct speed each time it is accessed. It is much faster to access than a floppy but it is currently
slower than a hard disc.
6. Photo CD:
Photo CD is a system designed by Kodak digitizing and storing photos in a CD. Launched in
1992 the discs were designed to hold nearly 100 high quality images, scanned prints and slides
using special proprietary encoding. Photo CD discs are defined in the Beige Book and conform
to the CD-ROM XA and CD-i Bridge specifications as well. They are intended to play on CD-i
players, Photo CD players and any computer with the suitable software irrespective of the
operating system The images can also be printed out on photographic paper with a special Kodak
machine
7. USB Flash drive:
A USB flash drive consists of a NAND-type flash memory data storage device integrated with a
USB (universal serial bus) interface. USB flash drives are typically removable and rewritable,
much smaller than a floppy disk (1 to 4 inches or 2.5 to 10 cm), and most USB flash drives
weigh less than an ounce. Storage capacities typically range from 64 MB to 64 GB with steady
improvements in size and price per gigabyte. Some allow 1 million write or erase cycles and
have 10-year data retention, connected by USB 1.1 or USB 2.0
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Input /Output Devices
Input/output devices are the devices that connect you to your computer. Input devices let you
input data and other information into your computer and they also let you give your computer
special instructions so that it will know what to do. For example, you can type in data by using a
keyboard, or you can input data in picture form by using a scanner. On the other hand, output
devices display the results of your computer's computations. Examples of these would be your
computer's monitor, which displays all of the programs you're running, as well as the printer,
which will print out a hard copy of the information!
Input Devices:
1. Keyboard:
I'm sure that you all know what a keyboard is. A keyboard is what you use to type in letters,
numbers, and other characters. You can type instructions in to your computer, or you can use the
keyboard to type up documents.
2. Mouse:
Mouse have been around for some while now. Mouse are used to manuever the cursor on your
computer screen to give instructions to your computer and to run programs and applications.
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3. Scanner:
Scanners let you put pictures and images onto your computer. They convert pictures and iamges
to digital form so that you can edit them by using the computer or put them on the Internet!
4. Digital Camera:
Digital cameras are somewhat similar to regular cameras. You can take pictures of people,
places, or things. However, digital cameras convert
these pictures to digital form so they can be used on the computer.
Output Devices:
1. Monitor:
Your monitor is a fancy term for your computer screen. It displays the programs and applications
you are running.
2. Liquid Crystal Displays:
LCDs, or liquid crystal displays, are similar to monitors. They, too, are screens that display
information, programs, and applications! LCDs are generally used on laptop computers.
3. Printer:
Printers let you take documents, pictures, and other files and &“quitrent" them out. They create a
hard copy of these files on a piece of paper.
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4. Audio Devices
Sound effects and music are vital to the computer's success. Computer games are all equipped
with amazing sound effects and music, while popular songs can be downloaded off the Internet.
There are a few devices that make this possible.
a) Sound Cards:
Sound cards are devices that can record sound, playback sounds, or even manipulate sounds!
They are a very important audio device.
b) Speakers:
Once you have recorded a sound file, you can use your speakers to listen to the music or other
sound! Speakers change the electrical signals from your sound files and converts them into
sound waves that we can hear.
5. Modems
Modem, a combination of the words modulator and demodulator, is a special device used to send
data over a phone line to other computers! Most modems are connected to an ISP, or Internet
Server Provider, which then connect us to the Internet and to the information super highway! In
order to transfer information between computers via a phone line, the digital information of
computers had to be translated into analog information, and then changed back to digital form
when reaching its destination. This was done by modems. At one end, modems would modulate
the data. This means that they would convert the data from digital form to a series of analog
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signals. Once the information successfully passed through the phone lines, another modem
would demodulate the data- convert the data from analog form back to digital form.
6. Connecting Cables
Computer system is made of a bunch of devices working together to get perform a certain
function. Well, it makes sense that these devices all need some way to communicate with each
other in order to function together. The cables we will describe in this section serve the purpose
of connecting peripherals and other components of a computer system to each other, to the
computer's memory, and to the computer's CPU.
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PRACTICAL: 2
INTRODUCTION TO NETWORK COMPUTING
Introduction:
A computer network is a group of interconnected computers. Networks may be classified
according to a wide variety of characteristics. This article provides a general overview of some
types and categories and also presents the basic components of a network. A network is a
collection of computers and devices connected to each other. The network allows computers to
communicate with each other and share resources and information.
Computer networks can also be classified according to the hardware and software technology that is used
to interconnect the individual devices in the network, such as Optical fiber, Frequently deployed devices
include hubs, switches, bridges and/or routers.Wireless LAN technology is designed to connect devices
without wiring. These devices use radio waves or infrared signals as a transmission medium.
Computer networks may be classified according to the network topology upon which the
network is based, such as bus network, star network, ring network, mesh network, star-bus
network, tree or hierarchical topology network. Network topology signifies the way in which
devices in the network see their logical relations to one another. Even if networked computers
are physically placed in a linear arrangement, if they are connected via a hub, the network has a
Star topology, rather than a bus topology. In this regard the visual and operational characteristics
of a network are distinct; the logical network topology is not necessarily the same as the physical
layout. Networks may be classified based on the method of data used to convey the data, these
include digital and analog networks.
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Network Connections
A. Media:
Network media (sometimes referred to as networked media) refers to media mainly used in
computer networks such as the Internet.
Network media is essentially driven by technological development, emerging from the
internet as a non-centralized medium in the late nineties, the term has more recently begun to
be applied to both the arts and industry. The following features distinguish Network Media
from classical media, such as broadcast media and the printed press:



Network Media is typically democratic and decentralized. The audience can also be the
contributors.
Network Media often requires the involvement of computers as an input/output device.
Network media requires a community to participate and consume
With the rapidly increasing digital era, new aspects of digital networking are becoming more
important. The benefits of the development of inter-networking ultimately has allowed for
greater political, social comment and discussion but is also widely thought of in a much broader
context of globalisation and the fragmentation of the world.
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B. Topology:
Network topology is the study of the arrangement or mapping of the elements(links, nodes, etc.)
of a network, especially the physical (real) and logical (virtual) interconnections between nodes.
A local area network (LAN) is one example of a network that exhibits both a physical topology
and a logical topology. Any given node in the LAN will have one or more links to one or more
other nodes in the network and the mapping of these links and nodes onto a graph results in a
geometrical shape that determines the physical topology of the network. Likewise, the mapping
of the flow of data between the nodes in the network determines the logical topology of the
network. The physical and logical topologies might be identical in any particular network but
they also may be different.
Any particular network topology is determined only by the graphical mapping of the
configuration of physical and/or logical connections between nodes. LAN Network Topology is,
therefore, technically a part of graph theory. Distances between nodes, physical interconnections,
transmission rates, and/or signal types may differ in two networks and yet their topologies may
be identical.
C. Sharing Information:
The term "information sharing" in the information technology lexicon has a long history.
Traditional information sharing referred to one-to-one exchanges of data between a sender and
receiver. These information exchanges are implemented via dozens of open and proprietary
protocols, message and file formats. Electronic data interchange ("EDI") is a successful
implementation of commercial data exchanges that began in the late 1970s and remains in use
today. From the point of view of a computer scientist, the four primary information sharing
design patterns are sharing information one-to-one, one-to-many, many-to-many, and many-toone. Technologies to meet all four of these design patterns are evolving and include blogs, wikis,
really simple syndication, tagging, and chat.
Important Terms Used In Network
A.
Gateway:
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In telecommunications, the term gateway has the following meaning:

In a communications network, a network node equipped for interfacing with another network
that uses different protocols.
o A gateway may contain devices such as protocol translators, impedance matching
devices, rate converters, fault isolators, or signal translators as necessary to provide
system interoperability. It also requires the establishment of mutually acceptable
administrative procedures between both networks.
o A protocol translation/mapping gateway interconnects networks with different
network protocol technologies by performing the required protocol conversions.
Gateways, also called protocol converters, can operate at any layer of the OSI model. The job of a
gateway is much more complex than that of a router or switch. Typically, a gateway must convert one
protocol stack into another.
B.
Hub:
A network hub or repeater hub is a device for connecting multiple twisted pair or fiber optic
Ethernet devices together and thus making them act as a single network segment. Hubs work at
the physical layer (layer 1) of the OSI model. The device is thus a form of multiport repeater.
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Repeater hubs also participate in collision detection, forwarding a jam signal to all ports if it
detects a collision.
Hubs also often come with a BNC and/or AUI connector to allow connection to legacy
10BASE2 or 10BASE5 network segments. The availability of low-priced network switches has
largely rendered hubs obsolete but they are still seen in older installations and more specialized
applications.
C.
Bridge:
A network bridge connects multiple network segments at the data link layer (layer 2) of the OSI
model, and the term layer 2 switch is very often used interchangeably with bridge. Bridges are
similar to repeaters or network hubs, devices that connect network segments at the physical
layer; however, with bridging, traffic from one network is managed rather than simply
rebroadcast to adjacent network segments. In Ethernet networks, the term "bridge" formally
means a device that behaves according to the IEEE 802.1D standard—this is most often referred
to as a network switch in marketing literature.
Bridges tend to be more complex than hubs or repeaters. Bridges can analyze incoming data
packets to determine if the bridge is able to send the given packet to another segment of the
network.
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D.
Switch:
A network switch is a computer networking device that connects network segments.
The term commonly refers to a Network bridge that processes and routes data at the Data link
layer (layer 2) of the OSI model. Switches that additionally process data at the Network layer
(layer 3 and above) are often referred to as Layer 3 switches or Multilayer switches.
The term network switch does not generally encompass unintelligent or passive network devices
such as hubs and repeaters.
The first Ethernet switch was introduced by Kalpana in 1990.
E.
Router:
A router is a networking device whose software and hardware are usually tailored to the tasks of
routing and forwarding information. For example, on the Internet, information is directed to
various paths by routers.
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Routers connect two or more logical subnets, which do not necessarily map one-to-one to the
physical interfaces of the router The term "layer 3 switch" often is used interchangeably with
router, but switch is a general term without a rigorous technical definition. In marketing usage, it
is generally optimized for Ethernet LAN interfaces and may not have other physical interface
types. In comparison, a network hub does not do any routing, instead every packet it receives on
one network line gets forwarded to all the other network lines.
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PRACTICAL: 3
CLIENT-SERVER ARCHITECTURE
Client Server Architecture:
Under the structure of the client-server architecture, a business's computer network will have a
server computer, which functions as the "brains" of the organization, and a group of client
computers, which are commonly called workstations. The server part of the client-server
architecture will be a large-capacity computer, perhaps even a mainframe, with a large amount of
data and functionality stored on it. The client portions of the client-server architecture are smaller
computers that employees use to perform their computer-based responsibilities.
Businesses of various sizes have various computer needs. Larger businesses necessarily need to
use more computers than smaller businesses do. Large businesses routinely have large computer
setups, such as mainframes and networks. A network for a large business commonly has a clientserver architecture, also known as a two-tier architecture. No matter what it is called, this type of
architecture is a division of labor for the computing functions required by a large business.
Servers commonly contain data files and applications that can be accessed across the network, by
workstations or employee computers. An employee who wants to access company-wide data
files, for instance, would use his or her client computer to access the data files on the server.
Other employees may use a common-access application by accessing the server through their
client computers.
This type of server is called an application server.It takes full advantage of the client-server
architecture by using the server as a storage device for applications and requiring the clients to
log in to the server in order to use those applications. Examples of this kind of application are
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numerous; among the most popular are word processors,spreadsheets, and graphic design
programs. In each case, the use of the applications illustrates the client-server architecture.
The server is not just for storage, however. Many networks have a client-server architecture in
which the server acts as a processing power source as well. In this scenario, the client computers
are virtually "plugged in" to the server and gain their processing power from it. In this way, a
client computer can simulate the greater processing power of a server without having the
requisite processor stored within its framework. Here, the client-server architecture describes a
virtual sort of power plant.
Even the World Wide Web is an example of client-server architecture. Each computer that uses a
web browseris a client, and the data on the various Web pages that those clients access is stored
on multiple servers.
Peer to Peer Architecture:
It is a type of network architecture in which each node has equivalent responsibilities. Both
client/server and peer-to-peer architectures are widely used, and each has unique advantages and
disadvantages. Client-server architectures are sometimes called two-tier architectures.
A peer-to-peer (or P2P) computer network uses diverse connectivity between participants in a
network and the cumulative bandwidth of network participants rather than conventional
centralized resources where a relatively low number of servers provide the core value to a
service or application. P2P networks are typically used for connecting nodes via largely ad hoc
connections. Such networks are useful for many purposes. Sharing content files (see file sharing)
containing audio, video, data or anything in digital format is very common, and real time data,
such as telephony traffic, is also passed using P2P technology.
A pure P2P network does not have the notion of clients or servers but only equal peer nodes that
simultaneously function as both "clients" and "servers" to the other nodes on the network. This
model of network arrangement differs from the client-server model where communication is
usually to and from a central server. A typical example of a file transfer that is not P2P is an FTP
server where the client and server programs are quite distinct: the clients initiate the
download/uploads, and the servers react to and satisfy these requests.
In contrast to the above discussed pure P2P network, an example of a distributed discussion
system that also adopts a client-server model is the Usenet news server system, in which news
servers communicate with one another to propagate Usenet news articles over the entire Usenet
network. Particularly in the earlier days of Usenet, UUCP was used to extend even beyond the
Internet. However, the news server system acted in a client-server form when individual users
accessed a local news server to read and post articles. The same consideration applies to SMTP
email in the sense that the core email relaying network of Mail transfer agents follows a P2P
model while the periphery of e-mail clients and their direct connections is client-server. Tim
Berners-Lee's vision for the World Wide Web, as evidenced by his WorldWideWeb
editor/browser, was close to a P2P network in that it assumed each user of the web would be an
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active editor and contributor creating and linking content to form an interlinked "web" of links.
This contrasts to the more broadcasting-like structure of the web as it has developed over the
years.
Hybrid Network:
Hybrid network is a local area network (LAN) containing a mix of both wired and wireless client
devices. In home networks, wired computers and other devices generally connect with Ethernet
cables, while wireless devices normally use WiFi technology. Most of the consumer WiFi
wireless routers support hybrid networks that include Ethernet clients. Traditional broadband
routers that lack WiFi capability, however, do not.
A particular model of wireless router can be varified to support a hybrid network by looking for the
following specifications on these products:
1)"10/100 Ethernet ports" or
2)"N-port Ethernet switch" (where N is a number such as "4" or "5") or
3)"wired LAN ports"
A mention of any of the above specs (and slight variations on these) indicate hybrid network
capability.
The majority of hybrid network routers allow connection of up to four wired devices. These can
be 4 computers or any combination of computers and other Ethernet devices. Connecting an
Ethernet hub to one of the router's ports allow more than 4 wired devices to be joined to the LAN
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through the method of daisy chaining. Wireless routers offering only one Ethernet port are
generally incapable of hybrid networking. This one port will typically be reserved for use by the
broadband modem and connection to the wide area network (WAN).
Direct Cable Connection:
Direct Cable Connection (DCC), is a feature of Microsoft Windows that allows a computer to
transfer and share files (or connected printers) with another computer, via a connection using
either the serial port, parallel port or the infrared port of each computer. It is well-suited for
computers that do not have an ethernet adapter installed, although DCC in Windows XP can be
configured to use one (with a proper crossover cable if no network hub is used) if available.
Contents of a direct cable connection :
1) DCC with Serial Port
2 )DCC with Parallel Port
3 )DCC with IR
4 )DCC with USB
5 )Windows Vista changes
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6)References
8 )External links
1) DCC with Serial Port
If using the serial ports of the computer, a null modem cable (or a null modem adapter connected
to a standard serial cable) must be used to connect each of the two computers to communicate
properly.
2) DCC with Parallel Port
If the parallel ports are used, Windows supports standard or basic 4-bit cable (commonly known
as LapLink cable), Enhanced Capabilities Port (ECP) cable, or Universal Cable Module (UCM)
cable (which was known as DirectParallel cable by Parallel Technologies).
3) DCC with IR
Infrared communication ports, like the ones found on laptop computers (such as IrDA), can also
be used.
4) DCC with USB
Connecting any two computers using USB requires a special proprietary bridge cable solution;
the usual USB-to-USB cable does not work as USB does not support such type of
communication and attempting to do so may even damage the connecting computers as it can
short the two computers' power supplies together, possibly destroying one or
both machines or causing a fire hazard. Therefore, Direct Cable Connection over USB is not
possible; a USB link cable must be used, as seen in the Microsoft knowledge base article
814982. However, with a USB link cable, a program which supports data transfer using that
cable must be used. Typically, such a program is supplied with the USB link cable. The DCC
wizard or Windows Explorer cannot be used to transfer files over a USB link cable.
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PRACTICAL: 4
STUDY OF LAN(ITS INSTALLATION) ITS COMPONENTS
AND ITS TOPOLOGIES
INTRODUCTION:A local area network (LAN) is a computer network covering a small physical area, like a home,
office, or small group of buildings, such as a school, or an airport. The defining characteristics of
LANs, in contrast to wide-area networks (WANs), include their usually higher data-transfer
rates, smaller geographic place, and lack of a need for leased telecommunication lines.
ARCNET, Token Ring and many other technologies have been used in the past, and G.hn may
be used in the future, but Ethernet over unshielded twisted pair cabling, and Wi-Fi are the two
most common technologies currently in use.
History
As larger universities and research labs obtained more computers during the late 1960s, there
was increasing pressure to provide high-speed interconnections. A report in 1970 from the
Lawrence Radiation Laboratory detailing the growth of their "Octopus" network, gives a good
indication of the situation.
Cambridge Ring was developed at Cambridge University in 1974 but was never developed into a
successful commercial product. Ethernet was developed at Xerox PARC in 1973–1975, and filed
as U.S. Patent 4,063,220. In 1976, after the system was deployed at PARC, Metcalfe and Boggs
published their seminal paper - "Ethernet: Distributed Packet-Switching For Local Computer
Networks"
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COMPONENTS OF LAN :
The three types lan components are:



Wireless network cards
Wireless access points
Wireless bridges
WIRELESS NETWORK CARD:
Wireless network cards come in a couple of flavours, including a PCI card for workstations and
PC cards for laptops and other mobile devices. They can act in an ad hoc mode, as in client-toclient, or in a pure client-to-access point mode. In an ad hoc mode, the wireless network card is
configured to talk with other wireless network access cards that are within its range. This
functionality will vary depending on the product and the 802.11 specification being used. Clientto-client (also know as peer-to-peer) WLANs are useful for small roaming workgroups of
desktops or laptops that do not require access to the LAN backbone. The plug and play
capabilities of most wireless network cards make this type of setup rather simple.
WIRELESS ACCESS POINTS:
Most wireless network cards will connect to an access point. An access point is essentially a hub
that gives wireless clients the ability to attach to the wired LAN backbone. The use of more than
one access point in a given area is facilitated by the use of cell structures, which are similar to
what mobile phone providers use to maintain your coverage area.
Locations closer to the centre of an access point radius will experience higher throughput than
those that are closer to the outside of the cell coverage area. This is facilitated by auto shifting,
which allows the data rate to downshift based on distance from access point. Again, this
functionality will vary depending on the product and 802.11 standard used.
One of the greatest benefits to roaming mobile users is the ability for one access point to hand off
communication to the next access point in the roaming cell.
WIRELESS BRIDGES:
Locations closer to the centre of an access point radius will experience higher throughput than
those that are closer to the outside of the cell coverage area. This is facilitated by auto shifting,
which allows the data rate to downshift based on distance from access point. Again, this
functionality will vary depending on the product and 802.11 standard used. One of the greatest
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benefits to roaming mobile users is the ability for one access point to hand off communication to
the next access point in the roaming cell.
LAN TOPOLOGY:
WHAT IS A 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.
MAIN TYPES OF PHYSICAL TOPOLOGIES:
The following sections discuss the physical topologies used in networks and other related topics.






Linear Bus
Star
Star-Wired Ring
Tree
Considerations When Choosing a Topology
Summary Chart
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
LocalTalk networks use a linear bus topology.
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Advantages of a Linear Bus Topology


Easy to connect a computer or peripheral to a linear bus.
Requires less cable length than a star topology.
Disadvantages of a Linear Bus Topology




Entire network shuts down if there is a break in the main cable.
Terminators are required at both ends of the backbone cable.
Difficult to identify the problem if the entire network shuts down.
Not meant to be used as a stand-alone solution in a large building.
STAR:
A star topology is designed with each node (file server, workstations, and peripherals) connected
directly to a central network hub or concentrator (See fig. 2).
Data on a star network passes through the hub or concentrator before continuing to its
destination. The hub or concentrator 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;
however, it can also be used with coaxial cable or fiber optic cable.
Advantages of a Star Topology



Easy to install and wire.
No disruptions to the network then connecting or removing devices.
Easy to detect faults and to remove parts.
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Disadvantages of a Star Topology



Requires more cable length than a linear topology.
If the hub or concentrator fails, nodes attached are disabled.
More expensive than linear bus topologies because of the cost of the
concentrators.
The protocols used with star configurations are usually Ethernet or LocalTalk. Token Ring uses a
similar topology, called the star-wired ring.
STAR WIRED RING:
A star-wired ring topology may appear (externally) to be the same as a star topology. Internally,
the MAU (multistation access unit) of a star-wired ring contains wiring that allows information
to pass from one device to another in a circle or ring (See fig. 3). The Token Ring protocol uses a
star-wired ring topology.
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 (See fig. 4). Tree
topologies allow for the expansion of an existing network, and enable schools to configure a
network to meet their needs.
Advantages of a Tree Topology


Point-to-point wiring for individual segments.
Supported by several hardware and software venders.
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Disadvantages of a Tree Topology



Overall length of each segment is limited by the type of cabling used.
If the backbone line breaks, the entire segment goes down.
More difficult to configure and wire than other topologies.
RING:
In a ring network, every device has exactly two neighbors for communication purposes. All
messages travel through a ring in the same direction (either "clockwise" or "counterclockwise").
A failure in any cable or device breaks the loop and can take down the entire network. To
implement a ring network, one typically uses FDDI, SONET, or Token Ring technology. Ring
topologies are found in some office buildings or school campuses.
MESH TOPOLOGY:
Mesh topologies involve the concept of routes. Unlike each of the previous topologies, messages
sent on a mesh network can take any of several possible paths from source to destination. (Recall
that even in a ring, although two cable paths exist, messages can only travel in one direction.)
Some WANs, most notably the Internet, employ mesh routing.
A mesh network in which every device connects to every other is called a full mesh. As shown in
the illustration below, partial mesh networks also exist in which some devices connect only
indirectly to others.
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HYBRID TOPOLOGY:
A combination of any two or more network topologies. Note 1: Instances can occur where two
basic network topologies, when connected together, can still retain the basic network character,
and therefore not be a hybrid network. For example, a tree network connected to a tree network
is still a tree network. Therefore, a hybrid network accrues only when two basic networks are
connected and the resulting network topology fails to meet one of the basic topology definitions.
For example, two star networks connected together exhibit hybrid network topologies. Note 2: A
hybrid topology always accrues when two different basic network topology.
LAN INSTALLATION:
CAREFUL PLANNING:
As with any other project, the planning of a WLAN installation involves establishing a schedule
and assigning resources We'll also need to accomplish some up front coordination to ensure that
the installation is completed on schedule. The access points will tie back to switches via
Ethernet; therefore, you need to communicate with the people responsible for supporting the
existing Ethernet systems if they already exist. When considering the installation schedule, think
about the time of installation. The best approach is to install access points and the distribution
system during operational downtimes.
IDENTIFY LOCATIONS FOR ACESS POINTS:
The installation locations of access points have significant impact on performance. When
deciding where to place an access point, bear in mind coverage and performance requirements.
You shouldn't over do it when meeting these requirements because of possibly of running out of
access point channels. Also take into account the maximum cable length limitations (100 meters)
for the cable running from the Ethernet switch to the access point. For best signal propagation
results, mount the access points as high as possible.
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INSTALL THE DISTRIBUTION SYSTEM:
The distribution system includes Ethernet switches and possibly routers along with Category 5
twisted pair cabling that runs to each access point. Be sure to label all cables according to
company specifications or methods that you define. The main idea is to identify each end of the
cable by some number scheme that lets you know which access point you're dealing with.
CONFIGURE AND INSTALL ACESS POINTS:
In most cases, especially when you have multiple access points, you won't be able to meet
requirements and the design using the default access point settings. Besides the 802.11 settings,
you need to configure the Internet protocol (IP) address to comply with an effective IP address
plan. Be sure to do this before mounting the access point to avoid difficulties in finalizing the
installation.
DOCUMENT THE FINAL INSTALLATION:
After completing the installation, don't forget to carefully document what was done.
Documentation should include a diagram depicting the location of installed access points and
applicable configuration settings.
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PRACTICAL:5
FAMILIARIZATION WITH TRANSMISSON MEDIA
There are 2 basic categories of Transmission Media:
1.
2.
Guided and
Unguided.
Guided Transmission Media:
Guided Transmission Media uses a "cabling" system that guides the data signals along a specific
path. The data signals are bound by the "cabling" system. Guided Media is also known as Bound
Media. Cabling is meant in a generic sense in the previous sentences and is not meant to be
interpreted as copper wire cabling only. There 4 basic types of Guided Media:
1) Open Wire:
Open Wire is traditionally used to describe the electrical wire strung along power poles.
There is a single wire strung between poles. No shielding or protection from noise
interference is used. We are going to extend the traditional definition of Open Wire to
include any data signal path without shielding or protection from noise interference. This can
include multiconductor cables or single wires. This media is susceptible to a large degree of
noise and interference and consequently not acceptable for data transmission except for short
distances under 20 ft.
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2) Twisted Pair Cable:
Twisted pair cabling is a form of wiring in which two conductors (the forward and return
conductors of a single circuit) are twisted together for the purposes of canceling out
electromagnetic interference (EMI) from external sources; for instance, electromagnetic
radiation from unshielded twisted pair (UTP) cables, and crosstalk between neighboring
pairs. The wires in Twisted Pair cabling are twisted together in pairs. Each pair would consist
of a wire used for the +ve data signal and a wire used for the -ve data signal. Any noise that
appears on 1 wire of the pair would occur on the other wire. Because the wires are opposite
polarities, they are 180 degrees out of phase (180 degrees - phasor definition of opposite
polarity). When the noise appears on both wires, it cancels or nulls itself out at the receiving
end. Twisted Pair cables are most effectively used in systems that use a balanced line method
of transmission: polar line coding (Manchester Encoding) as opposed to unipolar line coding
(TTL logic).
Unshielded twisted pair (UTP):
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Twisted pair cables were first used in telephone systems by Alexander Graham Bell in 1881. By
1900, the entire American telephone line network was either twisted pair or open wire with
similar arrangements to guard against interference. Today, most of the millions of kilometres of
twisted pairs in the world are outdoor landlines, owned by telephone companies, used for voice
service, and only handled or even seen by telephone workers.
Cable Shielding:
Twisted pair cables are often shielded in attempt to prevent electromagnetic interference.
Because the shielding is made of metal, it may also serve as a ground. However, usually a
shielded or a screened twisted pair cable has a special grounding wire added called a drain wire.
This shielding can be applied to individual pairs, or to the collection of pairs. When shielding is
applied to the collection of pairs, this is referred to as screening. The shielding must be grounded
for the shielding to work.
Screened unshielded twisted pair (S/UTP)
Also known as Fully shielded] (or Foiled) Twisted Pair (FTP), is a screened UTP cable (ScTP).
Shielded twisted pair (STP or STP-A)
STP cabling includes metal shielding over each individual pair of copper wires. This type of
shielding protects cable from external EMI (electromagnetic interferences). e.g. the 150 ohm
shielded twisted pair cables defined by the IBM Cabling System specifications and used with
token ring networks.
Screened shielded twisted pair (S/STP or S/FTP)
S/STP cabling, also known as Screened Fully shielded Twisted Pair (S/FTP), is both individually
shielded (like STP cabling) and also has an outer metal shielding covering the entire group of
shielded copper pairs (like S/UTP). This type of cabling offers the best protection from
interference from external sources, and also eliminates alien crosstalk.
Coaxial Cable:
Coaxial Cable consists of 2 conductors. The inner conductor is held inside an insulator with the
other conductor woven around it providing a shield. An insulating protective coating called a
jacket covers the outer conductor. The outer shield protects the inner conductor from outside
electrical signals. The distance between the outer conductor (shield) and inner conductor plus the
type of material used for insulating the inner conductor determine the cable properties or
impedance. Typical impedances for coaxial cables are 75 ohms for Cable TV, 50 ohms for
Ethernet Thinnet and Thicknet. The excellent control of the impedance characteristics of the
cable allow higher data rates to be transferred than Twisted Pair cable.
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3) Optical Fiber Cable:
An optical fiber cable is a cable containing one or more optical fibers. The optical fiber
elements are typically individually coated with plastic layers and contained in a protective tube
suitable for the environment where the cable will be deployed. Optical Fibre consists of thin
glass fibres that can carry information at frequencies in the visible light spectrum and beyond.
The typical optical fibre consists of a very narrow strand of glass called the Core. Around the
Core is a concentric layer of glass called the Cladding. A typical Core diameter is 62.5 microns
(1 micron = 10-6 meters). Typically Cladding has a diameter of 125 microns. Coating the
cladding is a protective coating consisting of plastic, it is called the Jacket.
Unguided Transmission Media:
Unguided Transmission Media consists of a means for the data signals to travel but nothing to
guide them along a specific path. The data signals are not bound to a cabling media and as such
are often called Unbound Media.
Radio Frequency Propagation:
Radio propagation is a term used to explain how radio waves behave when they are transmitted,
or are propagated from one point on the Earth to another. Like light waves, radio waves are
affected by the phenomena of reflection, refraction, diffraction, absorption and scattering. Radio
propagation in the Earth's atmosphere is affected by the daily changes of ionization in upper
atmosphere layers due to the Sun. Understanding the effects of varying conditions on radio
propagation has many practical applications, from choosing frequencies for international
shortwave broadcasters, to designing reliable mobile telephone systems, to operation of radar
system. Radio propagation is also affected by several other factors determined by its path from
point to point. This path can be a direct line of sight path or an over-the-horizon path aided by
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refraction in the ionosphere. Factors influencing ionospheric radio signal propagation can include
sporadic-E, spread-F, solar flares, geomagnetic storms, ionospheric layer tilts, and solar proton
events. There are three types of propagation:
Ground Wave Propagation:
a surface wave is a mechanical wave that propagates along the interface between differing
media, usually two fluids with different densities. A surface wave can also be an electromagnetic
wave guided by a refractive index gradient. In radio transmission, a ground wave is a surface
wave that propagates close to the surface of the Earth.
Ionosphere:
The ionosphere is the uppermost part of the atmosphere, distinguished because it is ionized by
solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of
the magnetosphere. It has practical importance because, among other functions, it influences
radio propagation to distant places on the Earth. It is located in the Thermosphere.
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Line Of Sight:
Line-of-sight propagation refers to electro-magnetic radiation including light emissions
traveling in a straight line. The rays or waves are diffracted, refracted, reflected, or absorbed by
atmosphere and obstructions with material and generally cannot travel over the horizon or behind
obstacles. Especially radio signals, at low frequencies (below approximately 2 MHz or so) these
signals travel as ground waves, which follow the Earth's curvature due to diffraction with the
layers of atmosphere. This enables AM radio signals in low-noise environments to be received
well after the transmitting antenna has dropped below the horizon.
1) Microwave:
Microwaves are electromagnetic waves with wavelengths ranging from 1mm - 1m, or
frequencies between 0.3 GHz and 300 GHz. As a consequence, practical microwave technique
tends to move away from the discrete resistors, capacitors, and inductors used with lower
frequency radio waves. Instead, distributed circuit elements and transmission-line theory are
more useful methods for design and analysis. Open-wire and coaxial transmission lines give way
to waveguides, and lumped-element tuned circuits are replaced by cavity resonators or resonant
lines. Effects of reflection, polarization, scattering, diffraction and atmospheric absorption
usually associated with visible light are of practical significance in the study of microwave
propagation. The same equations of electromagnetic theory apply at all frequencies.
Electromagnetic waves longer (lower frequency) than microwaves are called "radio waves".
Electromagnetic radiation with shorter wavelengths may be called "millimeter waves", terahertz
radiation or even T-rays. Definitions differ for millimeter wave band, which the IEEE defines as
110 GHz to 300 GHz.
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2) Satellite:
In the context of spaceflight, a satellite is an object which has been placed into orbit by
human endeavor. Such objects are sometimes called artificial satellites to distinguish them
from natural satellites such as the Moon.
Wireless networks:
Wireless network refers to any type of computer network that is wireless, and is commonly
associated with a telecommunications network whose interconnections between nodes is
implemented without the use of wires. Wireless telecommunications networks are generally
implemented with some type of remote information transmission system that uses
electromagnetic waves, such as radio waves, for the carrier and this implementation usually takes
place at the physical level or "layer" of the network. Types of wireless network are:
Wireless LAN:
A wireless LAN (WLAN) is a wireless local area network that links two or more computers or
devices using spread-spectrum or OFDM modulation technology based to enable communication
between devices in a limited area. This gives users the mobility to move around within a broad
coverage area and still be connected to the network.
For the home user, wireless has become popular due to ease of installation, and location freedom
with the gaining popularity of laptops. Large wireless network projects are being put up in many
major cities. Google is even providing a free service to Mountain View, California and has
entered a bid to do the same for San Francisco. New York City has also begun a pilot program to
cover all five boroughs of the city with wireless Internet access.
Wireless MAN:
A MAN is optimized for a larger geographical area than a LAN, ranging from several blocks of
buildings to entire cities. MANs can also depend on communications channels of moderate-tohigh data rates. A MAN might be owned and operated by a single organization, but it usually
will be used by many individuals and organizations. MANs might also be owned and operated as
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public utilities. They will often provide means for internetworking of local networks.
Metropolitan area networks can span up to 50km, devices used are modem and wire/cable. A
Metropolitan Area Network (MAN) is a large computer network that spans a metropolitan area
or campus. Its geographic scope falls between a WAN and LAN. MANs provide Internet
connectivity for LANs in a metropolitan region, and connect them to wider area networks like
the Internet.
.
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PRACTICAL:6
CONFIGURING NETWORK NEIGHBORHOOD
The network neighborhood icon is found on the Windows Desktop.
 Right-mouse-click the NETWORK NEIGHBOURHOOD. A drop down box will
appear.




Click Properties. The Network dialog box will appear.
Click on the TCP/IP Ethernet adapter.
Choose Properties.
The TCP/IP Properties box will appear.
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 Click on the IP address tab.
 Check Obtain an IP address automatically.
 Check the Gateway tab.
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 Ensure that NO gateways are installed.
 Click the DNS configuration tab.
 Check Disable DNS.
Now restart the system if asked, or necessary.
Configuring the Browser Netscape Configuration







Open Netscape
Select Edit
Select Preferences
Select Advanced
Select Proxies
Check Automatic Proxy configuration.
Click OK
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Netscape is now configured. The first time you access a web address outside the University of
Queensland domain, you will be prompted for a username and a password.
Once successfully authenticated you will be able to browse other web sites.
Internet Explorer configuration






Open Internet Explorer
Select Tools
Select Internet Options. A drop-down box will appear.
Select Connections from the Internet Options box.
Click LAN settings. A drop-down box will appear.
Check Use Automatic configuration script.
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EXPERIMENT: 7
IMPLEMENTATON OF PROTOCOLS AND ITS
CONFIGURATION
WHAT IS PROTOCOL?
In computers a protocol is basically a principle or standard which either controls or permits the
connection, communication and transmission of data between two diverse computing endpoints.
In basic language a protocol can be explained as the rules of leading the syntax, semantics and
synchronization of contact. There are two types of protocols they are Internet Protocol .
The OSI Reference Model is used to describe the architecture of networking protocols and
technologies and to show how they relate to one another. Its seven layers could be organized into
two layer groupings: the lower layers (1 through 4) and the upper layers (5 through 7).
TYPES OF PROTOCOLS
PHYSICAL LAYER (PROTOCOLS)
ADSL
Asymmetric Digital Subscriber Line (ADSL) is a form of DSL, a data communications
technology that enables faster data transmission over copper telephone lines than a conventional
voice band modem can provide. It does this by utilizing frequencies that are not used by a voice
telephone call. A splitter - or microfilter - allows a single telephone connection to be used for
both ADSL service and voice calls at the same time. ADSL can generally only be distributed
over short distances from the central office, typically less than 4 kilometres (2 mi),[2] but has
been known to exceed 8 kilometres (5 mi) if the originally-laid wire gauge allows for farther
distribution.
ISDN
Integrated Services Digital Network is a telephone system network. Prior to the ISDN, the
phone system was viewed as a way to transport voice, with some special services available for
data. The key feature of the ISDN is that it integrates speech and data on the same lines, adding
features that were not available in the classic telephone system.
ISDN is a circuit-switched telephone network system, that also provides access to packet
switched networks, designed to allow digital transmission of voice and data over ordinary
telephone copper wires, resulting in better voice quality than an analog phone. It offers circuitswitched connections (for either voice or data), and packet-switched connections (for data), in
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increments of 64 kbit/s. In a videoconference, ISDN provides simultaneous voice, video, and text
transmission between individual desktop videoconferencing systems and group (room)
videoconferencing systems.
DATALINK LAYER (PROTOCOLS)
ETHERNET
Ethernet is a family of frame-based computer networking technologies for local area networks
(LANs). The name comes from the physical concept of the ether. It defines a number of wiring
and signaling standards for the Physical Layer of the OSI networking model, through means of
network access at the Media Access Control (MAC) /Data Link Layer, and a common addressing
format.
Ethernet is standardized as IEEE 802.3. The combination of the twisted pair versions of Ethernet
for connecting end systems to the network, along with the fiber optic versions for site backbones,
is the most widespread wired LAN technology. It has been in use from around 1980[1] to the
present, largely replacing competing LAN standards such as token ring, FDDI, and ARCNET.
FDDI
Fiber distributed data interface (FDDI) provides a standard for data transmission in a local
area network that can extend in range up to 200 kilometers (124 miles). Although FDDI protocol
is a token ring network, it does not use the IEEE 802.5 token ring protocol as its basis; instead,
its protocol is derived from the IEEE 802.4 token bus timed token protocol. In addition to
covering large geographical areas, FDDI local area networks can support thousands of users.
FDDI, as a product of American National Standards Institute X3T9.5 (now X3T12), conforms to
the Open Systems Interconnection (OSI) model of functional layering of LANs using other
protocols. FDDI-II, a version of FDDI, adds the capability to add circuit-switched service to the
network so that it can also handle voice and video signals.
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Due to their speed, cost and ubiquity, fast Ethernet and (since 1998) Gigabit Ethernet have
largely made FDDI redundant.
FRAME RELAY
In the context of computer networking, frame relay consists of an efficient data transmission
technique used to send digital information. It is a message forwarding "relay race" like system in
which data packets, called frames, are passed from one or many start-points to one or many
destinations via a series of intermediate node points.
Network providers commonly implement frame relay for voice and data as an encapsulation
technique, used between local area networks (LANs) over a wide area network (WAN). Each
end-user gets a private line (or leased line) to a frame-relay node. The frame-relay network
handles the transmission over a frequently-changing path transparent to all end-users.
HDLC
High-Level Data Link Control (HDLC) is a bit-oriented synchronous data link layer protocol
developed by the International Organization for Standardization (ISO).
The current standard for HDLC is ISO 13239.HDLC provides both connection-oriented and
connectionless service. HDLC can be used for point to multipoint connections, but is now used
almost exclusively to connect one device to another, using what is known as Asynchronous
Balanced Mode (ABM). The original master-slave modes Normal Response Mode (NRM) and
Asynchronous Response Mode (ARM) are rarely used.
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POINT TO POINT PROTOCOL
In networking, the Point-to-Point Protocol, or PPP, is a data link protocol commonly used to
establish a direct connection between two networking nodes. It can provide connection
authentication, transmission encryption privacy, and compression.
PPP is used over many types of physical networks including serial cable, phone line, trunk line,
cellular telephone, specialized radio links, and fiber optic links such as SONET.
PPP is commonly used as a data link layer protocol for connection over synchronous and
asynchronous circuit. PPP was designed to work with numerous network layer protocols,
including Internet Protocol (IP), Novell's Internetwork Packet Exchange (IPX), NBF and
AppleTalk.
PPP is also used over broadband connections.
SPANNING TREE PROTOCOL (STP)
The Spanning Tree Protocol (STP) is a network protocol that ensures a loop-free topology for
any bridged LAN. In the OSI model for computer networking, STP falls under the OSI layer-2.
Spanning tree allows a network design to include spare (redundant) links to provide automatic
backup paths if an active link fails, without the danger of bridge loops, or the need for manual
enabling/disabling of these backup links. Bridge loops must be avoided because they result in
flooding the network.
The Spanning Tree Protocol (STP), is defined in the IEEE Standard 802.1D. As the name
suggests, it creates a spanning tree within a mesh network of connected layer-2 bridges (typically
Ethernet switches), and disables those links that are not part of the tree, leaving a single active
path between any two network nodes.
TOKEN RING
Token ring local area network (LAN) technology is a local area network protocol which resides
at the data link layer (DLL) of the OSI model. It uses a special three-byte frame called a token
that travels around the ring. Token ring frames travel completely around the loop.
TRANSPORT LAYER (PROTOCOL)
TCP
The Transmission Control Protocol (TCP) is one of the core protocols of the Internet Protocol
Suite. TCP was one of the two original components, with Internet Protocol (IP), of the suite, so
that the entire suite is commonly referred to as TCP/IP. Whereas IP handles lower-level
transmissions from computer to computer as a message makes its way across the Internet, TCP
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operates at a higher level, concerned only with the two end systems, for example, a Web browser
and a Web server. In particular, TCP provides reliable, ordered delivery of a stream of bytes
from a program on one computer to another program on another computer. Besides the Web,
other common applications of TCP include e-mail and file transfer. Among its other management
tasks, TCP controls message size, the rate at which messages are exchanged, and network traffic
congestion.
UDP
The User Datagram Protocol (UDP) is one of the core members of the Internet Protocol Suite,
the set of network protocols used for the Internet. With UDP, computer applications can send
messages, in this case referred to as datagrams, to other hosts on an Internet Protocol (IP)
network without requiring prior communications to set up special transmission channels or data
paths. UDP is sometimes called the Universal Datagram Protocol.
UDP uses a simple transmission model without implicit hand-shaking dialogues for guaranteeing
reliability, ordering, or data integrity. Thus, UDP provides an unreliable service and datagrams
may arrive out of order, appear duplicated, or go missing without notice. UDP stateless nature is
also useful for servers that answer small queries from huge numbers of clients. Unlike TCP,
UDP is compatible with packet broadcast (sending to all on local network) and multicasting
(send to all subscribers).
Common network applications that use UDP include: the Domain Name System (DNS),
streaming media applications such as IPTV, Voice over IP (VoIP), Trivial File Transfer Protocol
(TFTP) and many online games.
APPLICATION LAYER (PROTOCOLS)
FTP
File Transfer Protocol (FTP) is a network protocol used to exchange and manipulate files over
a TCP computer network, such as the Internet. An FTP client may connect to an FTP server to
manipulate files on that server.
HTTP
Hypertext Transfer Protocol (HTTP) is an application-level protocol for distributed,
collaborative, hypermedia information systems. Its use for retrieving inter-linked resources led to
the establishment of the World Wide Web.
HTTP is a request/response standard of a client and a server. A client is the end-user, the server
is the web site. The client making a HTTP request—using a web browser, spider, or other enduser tool—is referred to as the user agent. The responding server—which stores or creates
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resources such as HTML files and images—is called the origin server. In between the user agent
and origin server may be several intermediaries, such as proxies, gateways, and tunnels.
IMAP
The Internet Message Access Protocol or IMAP is one of the two most prevalent Internet
standard protocols for e-mail retrieval, the other being POP3. Virtually all modern e-mail clients
and servers support both protocols as a means of transferring e-mail messages from a server,
such as those used by Gmail, to a client, such as Mozilla Thunderbird, Apple Mail and Microsoft
Outlook. Once configured, the client's use of such protocols remains transparent to the user.
SMTP
Simple Mail Transfer Protocol (SMTP) is an Internet standard for electronic mail (e-mail)
transmission across Internet Protocol (IP) networks.
While electronic mail server software uses SMTP to send and receive mail messages, user-level
client mail applications typically only use SMTP for sending messages to a mail server for
relaying. For receiving messages, client applications usually use either the Post Office Protocol
(POP) or the Internet Message Access Protocol (IMAP) to access their mail box accounts on a
mail server.
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EXPERIMENT: 8
SHARING OF RESOURCES WITH TWO CONNECTED
NODES
To assign a (map) drive letter to a network computer or folder


You can also right-click Network Neighborhood, and then click Map Network Drive.
To map to a computer or folder you have recently used, click the arrow to the right of the
path, and then click the resource you want.
To remove a drive-letter assignment

You can also right-click Network Neighborhood, and then click Disconnect Network
Drive.
To connect to another computer on your network



On your desktop, double-click Network Neighborhood, and then double-click the
computer you want.
If you don’t see the computer you want, double-click Entire Network.
If the Network Neighborhood window is empty or the icon is missing, network is not
available. You need to set up networking to connect to another computer on the network.
To see resource use on another computer







Double-click the Network Neighborhood.
Click the name of the computer on which you’d like to view shared resources.
On the File menu, click Properties.
Click the Tools tab, and then click Net Watcher.
On the Net Watcher view menu, click the type of information you want to see.
Before you can see resource use on another computer, it must first be setup for remote
administration.
You must have an administrator or access permission to view the resource use on another
computer.
To open a shared folder on another computer

Double-click Network Neighborhood, and then double-click the computer where the data
is located.
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www.grasphub.com
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To see more computers, double-click Entire Network.
Double-click the folder you want to connect to.
You may want to assign a drive letter for shared folders that you connect too often.
To see what network printers and folders are available
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Double-click Network Neighborhood.
To see additional printers and folders that are available, double-click Entire Network.
Double-click the computer whose data you want to view.
If you can’t see a resource on the network, you might not have an access permission.
To use a shared network printer

Double-click Network Neighborhood, and then locate the computer with the printer you
want to use.
 Click the computer with the printer you want, and then click the printer icon.
To set up the printer, follow the instructions on the screen.

After you have set up a network printer, you can use it as if it were attached to your
computer.
 To see which computers have, on the View menu, click Details, and look for printer
names or descriptions in the Concurrent column.
Click the name of the server you want to detach from, and then click Detach.
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