The different types of computer
networks and the common sources of network problems in schools
The term
computer network refers to the largest physical appendage to our computer
systems but it is also the least conspicuous often hidden behind walls and in
locked switching rooms or passing invisibly through us as electromagnetic
radiation (Mark 2004)) on addition networking is a telecommunications network
that allows computers to exchange data. Therefore the types of computer network
include;
v Personal
Area Network: Is a
computer network used for communication among computer and different
information technological devices close to one person for example personal
computers, printers, fax machines, telephones, PDAS, scanners and video game consoles, it may include wired
and wireless devices of 10 meters. it’s usually constructed with USB and fire
wire connections with technologies such as blue tooth and infrared
communication typically a form of a wireless PAN.
v Local
area net work: connects
computers and devices in a limited geographical area such as home, school, office
building or closely positioned group of buildings each computer or device on
the network is anode based Ethernet technology ,never standards such as
IT.U.TG.HN also provide away to create a wired LAN.(Behrouz 2007)),on addition
to that the defining characteristics of LAN in contrast to WAN includes data transfer
rates, limited geographical range, lack of reliance on leased lines to provide
connectivity, LAN technologies operate at data transfer rate up to 10 GB, can
be connected to a WAN using a router. When computers which are connected together normally belong
to one organization and all computers are situated within a radius of 1km, the
network is LAN (Rajaraman 2010). Here
connection is easy without buying extra equipment. LAN is a computer network that spans a
relatively small area. That it can be connected to any other LANs over any
distances via telephones lines, radio waver. Most of them connect work stations
and personal stations. Different types of LANs are token ring network, Ethernet
and ARC nets and they are the common ones for PCs.( Leon 1999)
v Home
area net work: Is a
residential LAN which is used for communication between digital devices
typically deployed in the home , usually a small number of personal computer
and accessories such as computers and mobile computing devices of 1 million fun
sharing of internet access often abroad band services through a cable TV , a
digital line subscriber provider.(Sanjay.S 2003)
v Metropolitan
area net work: (city or large campus area net work) is a
computer net work that covers a large geographical area such as a city,
country, or spans even in the intercontinental distances. it uses communication
channel but combines many types of media such as telephone lines, cables and
air waves.(Behrouz2007). MAN
is a communication network covering a city or a suburb (William and Sawyer 2011).
The geographical area to be spanned by a computer network is a few 100sq.km. It
connection is usually the local telephone networks. it is specifically designed
to work with in a town or cities. This network consists of a high speed back
bone that is made up of fiber optic cables.
v Backbone
network: Is part
of the computer network infrastructure that provides a path for the exchange of
information between LANS and sub networks. (Mathews 1999) in aaddition , it can
also tie together diverse networks within the same building across different
buildings for example internet Z is asset of wide area networks and core
routers that tie together all the networks connected to the internet.
v Wide Area Network (WAN); it is a communication network that covers a
wide geographic area, such as a country or the world. (Williams and sawyer 2011).
Most of the telephone companies in the country use WAN, it may use satellites,
fiber optic cables, microwave and among others and here WANs are used to
connect LANs together so that users and computers can communicate in other
location.
The common Sources of network problems
Ø Cable
Problem: Cables that connect different parts
of a network can be cut or shorted. A short can happen when the wire conductor
comes in contact with another conductive surface, changing the path of the
signal. Cable testers can be used to test for many types of cable problems such
as Cut cable, incorrect cable connections, Cable shorts, Interference level,
Connector Problem (Mark.2004)) Due to the above statement the source of this
problem is the connection between wire conductor and other conductive.
Ø Connectivity
Problem: A connectivity problem with one or
more devices in a network can occur after a change is made in configuration or
by a malfunction of a connectivity component, such as hub, a router or a
Switch. . (Mark 2004) According to discussed view the source of the problem is
configuration of net work devices surface that change the path of the signal.
Ø Excessive
Network Collisions: These often lead to slow
connectivity. The problem can occur as a result of bad network setup plan, a
user transferring a lot of information or jabbering network card. (Mark 2004) The
source can be jabbering of the network
Card or unplanned set up of the network: A
connectivity problem with one or more devices in a network can occur after a change
is made in configuration or by a malfunction of a connectivity component, such
as hub, a router or a Switch.
Ø Duplicate
IP Addressing: A common problem in many networking
environments occurs when two machines try to use the same IP address. This can
result in intermittent communications. Common problem in many networking
environments occurs when two machine. (Mark 2004) The source may be when two machines try to use the same IP
Address.
Ø Internet
traffic load:
Spikes in Internet utilization during peak usage times of day often cause lag.
The nature of this lag varies by service provider and a person's geographic
location. Unfortunately, other than moving locations or changing Internet
service, an individual user cannot avoid this kind of lag. (Sanjay 2003) There
for the source of the problem is the personal geographical location and service
provider. For example when the user of the network is in low levels of
geographical location.
Ø Overloaded
router or modem:
network router will eventually bog
down if too many active clients are using it at the same time. Network contention
among multiple clients’ means that they are sometimes waiting for each other's
requests to be processed, causing lag. A person can replace their router with a
more powerful model, or add another router to the network, to help alleviate
this problem. Similarly, network contention occurs on a residence's modem and connection
to the Internet provider if saturated with traffic: Depending on the speed of
their Internet link, homeowners should avoid too many simultaneous Internet
downloads and online sessions to minimize this lag. (Sanjay 2003) the
identified source is the strength of the router or the modem.
Ø Virus and trajons; a computer virus is a piece of
malicious code that can infect the computer system. A trajon horse is a type of
virus for example net bus or black orifice, which is planned on your network
and takes control of the host computers. It can be programmed to do just about anything
to your system for example changing the IP address, install destructive
programs and among others. This damages the computer accessed the network
server and any damage inflicted affects the entire network.
Ø Denial of service (Dos) attack; it involves sending more requests to
a computer or network than it can handle. For example a computer answering 20
requests per second, and the attacker sends 45 requests per second; the
computer will be unable to serve all the attacker’s requests, so here the
computer gets over loaded and this damages the computer network.
Ø E-mail bombs; this type of attack is caused by
someone sending you the same e-mail very many times like over hundred times
until your network e-mail system can’t accept any more messages. This damages
the computer network as well as the computer system.
Ø Redirecting bombs this changes the
path of the information takes by sending to different router essentially.
Letting hackers erase their steps by using computers on your network to do
dirty work.
Ø Data diddling occurs when authorized
user accesses confidential data and changes it. For instance if someone breaks
into your network and moves a few decimal point in the master spread sheet or
transpose some digits in the numbers in the automatic pay roll systems not only
data changed but u might also not notice the change until something really bad
results.
REFERENCES
1.
Alexis Leon and Mathews Leon, (1999) Fundamentals of information
technology, published by vikas publishing house pvt ltd.
2.
Brian K.Williams/Stacey .C.Sawyer, (2011) Using information technology, a
practical introduction to computers and communications: complete version
published by mc Graw-hill a business unit of the mc Graw-hill companies.
3. Behrouz.
A. Forouzan (2007) Data communication and
networking, new york, mc graw-hill
international edition
4. Mark
burgess (2004) Principles of net work and
system administration, the atrium
southern gate chichester, john willy and sons ltd.
5.
Rajaraman .v, (2010) introduction to information technology, published by
phl learning private limited new delhi-11000.
6. Sanjay
Saxena (2003) A first course in computers,
india, asia. vikas publishing house p.v.t ltd.
