An Overview of the Computer Network Devices & Components

Author: Fiza Ali

Article:
An Overview of the Computer Network Devices & Components

By Fiza http://www.theitlibrary.com

A Computer network is comprised of different devices to share
and transmit the data and voice as well as to boost the signals.
Network devices or components are the physical parts connected
to a network. There are a large number of the network devices
and, which are increasing daily. The basic network devices are:
Individual Computers, Server, Hub, Switch, Bridges, Routers,
Modems, Printers, DSL Modems & Routers, Gateways, Network
Interface Cards, Cabling & Wireless access point. The following
is a overview of each of these network devices.

INDIVIDUAL COMPUTERS: The personal computer is usually a desktop
computer, a work station or a laptop. The personal computers are
most widely used in any organization or for personal use. The
individual computers are the most common types of the
microcomputers.

SERVER: A server is a computer on a network, which process
request and is used to share the data and resources among the
other computers in a network. A server stores all the necessary
information and provides the different services like,
workstation computer's logon access, internet sharing, print
sharing, disk space sharing etc. There are different types of
servers e.g File and print server, database server, proxy
server, Fax server, backup server etc. A database server stores
all the data and software, which may related to the certain
database and it allows other network devices to access and
process the database queries. A file server is used to store the
data of any user on the network and a print server manages one
or more printers in a network. Similarly a network server is a
server that manages the network traffic.

NETWORK INTERFACE CARD: Network interface cards are attached
with the computer or other network devices and are used to
provide the connectivity between the two computers. Each network
card is specifically designed for the different types of the
network like Ethernet, FDDI, Token Ring and Wireless Networks.
The Network card operates on the first and second layers of the
OSI models i.e Physical layer and datalink layer specifications.
NIC basically defines the physical connection methods and the
control signals that provides the timings of the data transfer
over the network.

HUBS: Hub is a simplest network device. The function of the hub
is broadcasting i.e data is forwarded towards the all ports of a
hub, regardless of whether the data was intended for the
particular systems in the network or not. Computers in a network
are connected to a hub with a twisted pair (CAT5) cables. There
are two types of the hubs. 1. Active Hubs. 2. Passive Hubs.

SWITCHING HUB: The Switching hub (also called "switch" is the
most advance shape of the basic hub. In a basic hub all the
computers are connected with the hub and the speed of the
network is defined by the slowest computer network card
connected. For example if you have 10/100 Mbps cards in a
network and only one card of 10Mbps speed then the system cannot
run faster than the 10 Mbps. Now if you have a switching hub in
a network, it will allow all the faster connections in the
network to remain at the higher speed and still interact with
the 10Mbps system.

SWITCHES: Switch is a intelligence device than hub. Switch is a
layer 2 device. Swith provides the same function as a hub or a
bridge but it has the advance functionality of connecting the
two computers together temporarily. Switch contains the switch
matrix or switch fabric that can connect and disconnect ports.
Unlike hubs, switch only transmit or forwards the data to the
destined computer and it does not broadcasts the data to all its
ports.

MODEMS: Modems are the devices, which are used to translate the
digital data into the analog format and vice versa. It performs
the two main functions. Modulation and demodulation. A modulated
data can travel across the conventional telephone lines. The
modem modulates the signals at the sending end and demodulates
at the receiving end. Modems are required for different types of
the access methods such ISDN, DSL and 56K data modem. Modem can
be the internal devices that plug into the expansion slots in a
system or can be external devices that plug into the serial or
USB ports. In Laptops, PCMCIA cards are used for this purpose
and many new laptops having the built in integrated modems. The
specialized devices are designed for use in the systems such as
handheld computers. In ISPs where the large scaled modems are
required, rack-mounted modems are used.

ROUTERS: Routers route the data between two logically and
physically different networks. A Router has the capability to
determine the destination address for the data and hence
provides the best way for the data to continue its journey.
Router gets this capability through its software called routing
software. Unlike Switches and Bridges, which use hardware
configured MAC address to determine the destination of the data,
router uses logical network address such as IP address to make
the decision in determining the destination of the data.

GATEWAY: A gateway performs the function of translating the data
from one format to another format without changing the data
itself. A gateway can be a device, system, software. A computer
with two NIC cards can function as a gateway. Router acts as a
gateway e.g a router that routes the data from a IPX network to
a IP network is technically a gateway. The same can be said of
translational switch converts from a Ethernet network to a token
ring network.

CABLES: There are two most common types of the cables. 1.
10baseT and 10base2. 10baseT is a four paired cable. 10baseT has
further two types 1. UTP (unshielded twisted pair) and 2. STP
(shielded twisted pair. STP is most secure cable covered with
the silver coated twisted paper to protect the cable. On the
other end Thin 10base2 looks like the copper coaxial cabling
that often used to connect TV sets and VCR. 10baseT/Cat5 cables
are most commonly used cables to connect the computers. It has
the connector, (like a telephone connector) called RJ45
connector.

Twisted pair cables are ideal for the small, medium or large
networks. My recommendation for using cables for computer
networking is to use 10baset/Cat5 cables. Regards Fiza
http://www.theitlibrary.com

About the author:
Fiza Ali http://www.theitlibrary.com

Acer Laptop Ac Adapter

Author: Frank Vanderlugt

Article:
You bought an Acer laptop because Acer is the third largest
computer manufacturer in the world and it still offers great
prices. You heard how Acer even merged with Gateway recently and
you know that Gateway has produced quality laptops for years, so
you're confident in the durability and function of your Acer
laptop.

There's just one problem. You broke the AC adapter cord that
came with your Acer laptop and you're running low on batteries.
Running an Acer laptop wire-free is great, but eventually you're
going to need to recharge that battery. Plus, sometimes it's
better to conserve the battery and use the AC adapter instead.

Or maybe you still have your Acer laptop AC adapter, but it's
awfully bulky and it makes bringing your laptop on airplanes and
business trips a real pain. You wish there was an easier way to
charge your Acer laptop.

Don't give up on your Acer laptop! Lucky for you, you can easily
secure an Acer laptop AC adapter and even a travel AC adapter
and consider the problem solved!

You need to know the model of your Acer laptop before you can
buy an AC adapter. You can't just ask a sales associate for an
Acer laptop AC adapter because every model of Acer laptop may
have a different AC adapter that will work with it.

Don't forget to bring along the manual or write down the model
number from the bottom of your Acer laptop when you visit the
electronics store if you're going to buy an AC adapter in town.
Otherwise, you can search for the correct Acer laptop AC adapter
online.

You can get a great deal on an Acer laptop AC adapter online.
First, try Acer.com to see if they have the correct AC adapter
for your particular model of Acer laptop in stock. Contact their
customer service for more help if you need it!

You might find a better deal on an Acer laptop AC adapter if you
shop around a little online. LaptopCharge.com specializes in AC
adapters for laptops and it has quite a number of Acer laptop AC
adapters, including "travel mate" editions that make it easier
for you to charge your Acer laptop on the go!

LaptopACAdapter.com is another AC adapter specialist company
with great deals on Acer laptop Ac adapters. They even guarantee
their laptop AC adapters for up to one year after purchase, so
if your break yours again or it goes on the fritz thanks to a
power surge, you can get a replacement free of charge!

There are plenty of places where you can replace your Acer
laptop AC adapter or get a travel Acer laptop AC adapter that
will make your business trips a whole lot easier. If you have
trouble figuring out which Acer laptop AC adapter is the one you
need, contact customer service at Acer.com!

About the author:
frank j vanderlugt owns and operates http://www.acer-laptops.com
Acer Laptops