The different types of computer networks and the common sources of network problems in schools

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.