|
Networking
Tutorials & Tips n Tricks
- (February - 2009)
What is Network?
A network or
communication network is a system of interconnected
communication devices that can communicate with one another and
share information. Therefore computer network can be defined as
A system in
which more than one computers or large number of computers are
interconnected together, communicate freely with one another and
share information is called computer network.
A network can be internal to an organization or span the world
by connecting itself to the internet. In computer network,
network operating system is used that controls and co-ordinates
the activities of computers that are connected to the network.
The example of these operating systems are: windows NT, UNIX,
and Novell etc.
Types of Network
Networks are of three types. These are:
-
Local Area Network (LAN)
-
Wide Area Network (WAN)
-
Metropolitan Area Network (MAN)
Local Area Network
A local area network is a network system in which computers are
interconnected in a limited geographical area, such as network
of computers in college computer laboratory or network of
computers in office building etc.
Wide Area Network
A wide area network is a network system that covers a large
geographical area such as different cities of country or
different countries of the world. In WAN telephone lines,
satellites, microwave, fiber optic etc. are used as transmission
media.
Metropolitan Area Network
A Metropolitan area Network is a network system that covers area
of a single city. Usually, MAN connects more than one LANS in a
city or town and covers a smaller geographical area than a WAN.
The cable television, telephone companies or local corporations
use MAN.
Basic
Networking
-
February 2009
A
network is a group of computers, printers, and other devices
that are connected together with cables. Information travels
over the cables, allowing network users to exchange documents &
data with each other, print to the same printers, and generally
share any hardware or software that is connected to the network
Each
computer, printer, or other peripheral device that is connected
to the network is called a node. Networks can have tens,
thousands, or even millions of nodes.
Like most things, networks are are assembled according to
certain rules. Cabling, for example, has to be a certain length,
each cabling strand can only support a certain amount of network
traffic etc, Nodes are essential components of any computer
networks. In general, these components are essential in
transmitting, receiving, and forwarding messages. Nodes can also
be computers, mobile phone, personal digital assistants (PDAs),
routers, switches, and any device that is connected to a
computer networks.
The rules that govern how a network is set up is called its
topology. The most popular topology in use today is called
Ethernet, which consists of computers and peripherals cabled
together in specific ways. Ethernet is relatively inexpensive,
easy to set up and use, and very, very fast.
Ethernet networks are categorized by how fast they can move
information. Speed is expressed in megabits per second (or
Mbps), where one "bit" is equal to 1/8th of a character, letter,
or number.
There are currently two Ethernet speed categories. Standard
Ethernet operates at a fast 10Mbps, which is quick enough for
most networking tasks. Fast Ethernet, by contrast, races along
at a blistering 100Mbps, making it ideal for desktop video,
multimedia, and other speed-hungry applications. The new
technology behind Fast Ethernet, which was introduced in the
beginning of 1995, is not readily compatible with standard
Ethernet.
Making the two "talk" with each other requires special equipment
and some knowledge of internetworking. If you're building your
first network, decide whether to go with standard or Fast
Ethernet before you begin shopping around for network hardware
and software. Unless you plan on using video, multimedia, or
heavy graphics software, plan on using standard Ethernet.
NETWORK GLOSSARY
- February 2009
Network Topologies
network topology is defined as: the schemes of joining a number
of computers in the form of a network are called Network
Topologies.
Physical Transmission media
In physical Transmission media, communication devices are
directly linked with each other via cables or other physical
materials for data communication.
Twisted-Pair Cable
It is one of the most commonly used communication media for
network cabling. It consists of two separate copper wires that
are covered by insulating material such as plastic and twisted
together to form a cable.
Coaxial Cable
Coaxial Cable is also referred to as coax. It consists of a
single copper wire surrounded by insulating materials. Usually,
it is surrounded by three layers.
-
Insulting
material
-
Solid metal
shield
-
External plastic
cover
Fiber-Optic Cable
In twisted-pair cable and coaxial cable, data is transmitted in
the form of electric frequencies. So copper wire has to be
protected from water and electromagnetic waves. In fiber optic
cable, these types of problems are not occurred. The fiber-optic
cable uses light to transmit data. A fiber-optic cable consists
of hundreds of thin glass fibers or strands of glass. Each
strand is referred to as optical cable.
Wireless
Networking
In Wireless transmission media, communication devices
communicate with each other and data is communicated through the
air or space using broadcast radio signals, microware signals
and infrared signals. This transmission medium is used when it
is impossible to install the cables. The data can be transmitted
all over the world through this medium.
Broadcast Radio
It is a wireless transmission medium that is used to communicate
information through radio signals in air, over long distance
such as between cities and countries. In this medium, a
transmitter is required to send messages and receiver is
required to receive them. To receive the broadcast radio signal,
the receiver has an antenna that is located in the range of
signal. Some networks use a special device called transceiver
used to send and to receive messages in the form of radio
signals. The data transmission speed of broadcast radio is up to
54 Mbps.
Cellular Radio
Cellular radio is a form of broadcast radio that is used for
mobile communication such as cellular and wireless modems. A
cellular telephone is a telephone device that uses high
frequency radio waves to transmit voice and digital messages.
Some mobile users connect their laptop computer or other mobile
device to a cellular telephone to access the web, send and
receive email while away from a standard telephone line.
Microwaves
Microwaves are radio waves that provide a high speed
transmission. In microwaves transmission, data is transmitted
from one station to another. Microwaves station contains an
antenna, transceiver and other equipments that are required for
microwave communication. The data transmission speed of
microwave transmission is up to 150 Mbps.
Digital Modem
The modem that is used to send and to receive data to and from a
digital telephone line is called digital modem. ISDN modem and
DSL modem are the best example of digital modem. These modem are
used to send and receive the digital data to and from the
digital line, So there is no need to convert to analog signals
because digital lines already use the digital signals.
Bridge
It is an electronic device that connects two same type of
networks and control the traffic between them. A bridge
basically split an overloaded network into two separate network
for reducing the amount of traffic on each segment and increase
the performance of each network. A bridge looks at the
information in each packet header and forwards data from one LAN
to another.
Router
An electronic device that connects many computers together and
transmits data to its correct destination using the available
path on the network is called router. It stores the information
of each node on the network and to use these information to
transfer date between nodes.
Gateway
A gateway is an electronic device that can perform logical
function. A gateway is a device or system (because it may be a
hardware or software) that connects two or more networks to
share their information from one to the other. Packets from
different networks have different type of information in their
headers, and information in different format. The gateway can
take a packet from one type of network, read the header, and
then encapsulates the entire packet into a new one, adding a
header that is understood by the network.
DNS (Domain Name
System)
A Domain Name System (DNS) is the method that the internet uses
to store domain names and their corresponding IP addresses. In
other word DNS resolves the host or domain name to IP addresses.
Each domain name is associated with a IP address like
131.200.1.1 four set of digit separated by dots.
Asynchronous
Transfer Mode (ATM)
Asynchronous Transfer Mode is an advanced data transmission way.
It is very fast and reliable data transmission connection line
that can carry data, audio, video, imaging and multimedia
transmission etc.
ROUTER AND ROUTING
A Router is an electronic device that used to connects multiple
computers, networks together and transmits data to its correct
destination using the available path on the network is called
router. You can say a router choose the best path for data
transfer on available paths.
IP Addressing
IP stands for
internet protocol. Basically it is a unique identifier for a
computer on the internet. It is numerical address with four
numbers separated with dots and
the format of an IP address is a 32-bit.Each number can be start
from 0 and ends with 255. For example
IP address looks like
this: 131.200.1.1
DSL
The DSL stand for Digital Subscriber Line. DSL provides high
speed on already exiting telephone lines and same time you can
use internet and as well as your line for phone. In DSL, both
ends of connections require the network cards and DSL modems
for data communication.
ADSL
ADSL stand for asymmetric digital subscriber line, here
asymmetric means data speed does not same in both directions
(upload and download) and provides high speed on already
exiting telephone lines and same time you can use internet and
as well as your line for phone.
Packets
The transfer of data from one place to another place in the form
of digital signals and this data is broken into small data
segment before being transmitted from one computer to another
computer. These small data segments are called packets.
VOIP
VOIP stand for Voice
over Internet Protocol, in common terms voice connection using
internet protocol through internet. In technical words VOIP is a
technology used to transmit voice using broadband internet
connection instead of old analog phone lines.
|
