However, even LAN’s have limitations.
WAN
Wide Area Network is a network connecting computers within very large areas, such as states, countries, and the world. It is, in a way, a group of LAN’s connected over longer distances. The Internet is a very large Wide Area Network.
WAN can be used by businesses to connect companies over large distances i.e. connecting devices kilometers away.
WAN’s are slower than LAN’s at transferring data, however recent development in fibre optic medium allowing large data transfer at speed.
To connect to WAN (The Internet) you will require a modem.
Encryption
Encryption is he translation of data into a secret code. Encryption is the most effective way to achieve data security. To read an encrypted file, you must have access to a secret key or password that enables you to decrypt it. Unencrypted data is called plain text; encrypted data is referred to as cipher text. Most e-commerce software applications utilize encryption technology.
Ethernet
Ethernet is a local area technology with networks operating in a single building. This is known as connecting devices in close proximity. Ethernet is usually connected using a few hundred meters of cable. Since this medium has improved it allows Ethernet to be connected over longer distances. Businesses may use Ethernet for internal use, within the company, to make an Intranet.
An Intranet is a private network inside a company or organization, which uses software like that, used on the Internet, but is for internal use only, and is not accessible to the public. Companies use Intranets to manage projects, provide employee information, distribute data and information, etc. The main purpose of an intranet is to share company information and computing resources among employees.
Extranet
An extranet is a private network that uses Internet protocols and public telecommunications lines. An extranet can be viewed as part of a company's intranet that is extended to users outside the company. The main purpose of an extranet is to share information with individuals or groups outside a company, such as suppliers, customers and partners.
Terms and Rules used in Networking
In networking, the term protocol refers to a set of rules that govern communication relations. Protocols are a language to computers. Both devices must understand must understand the same language, same protocol, to communicate. The Internet was setup using the TCP/IP protocol.
The medium is the type of cable used to connect the network, traditionally coaxial copper, and now fibre optic cable. Data is sent in chunks called frames through the segments. A segment is a single shared medium, which is connected with node devices.
In the Ethernet protocol there are set of rules, minimum and maximum length for frames and a set of required pieces in that frame. Each frame must contain a destination and source address. The address specifies the node.
A broadcast address can be used to send information to every node device i.e. to every computer.
An improvement in network technology has lead to developments in carrier sensing and collision detection (CSMA/CD). Carrier Sensor Multiple Access/Collision Detection
Multiple accesses means that all the stations hear the transmission and carrier sensor is when a station is going to transmit data it listens to see if another station is transmitting avoiding collision of data.
Collision detection is when two stations transmit at the same time and collide. This causes both stations to wait a random number of times and transmit again.
A disadvantage of Ethernet is that the signal transmitted can weaken over long distances. A network must be short enough so that devices can communicate clearly that is known as the network diameter.
To solve this problem companies may use repeaters in their network. These then allow repetition of data from one segment to another. These can significantly increase the network diameter.
Another disadvantage is that Ethernet networks can face congestion problems as the network diameter increases. If more stations are connected to a segment then collisions may be frequent. One way to reduce congestion is to split a single segment creating multiple session domains but these segments cannot share information. To solve this Ethernet networks are bridged. This echoes information from one segment to another. A bridge can reduce unnecessary traffic on segments. The bridge also filters out unnecessary frames. If something is broadcasted then the bridge will transmit to all stations.
Routers are advanced networking components that can divide a single network into two separate networks.
An that uses to connect individual or . In the case of individual hosts, the switch replaces the and effectively gives the device full 10 bandwidth (or 100 Mbps for ) to the rest of the network. This type of network is sometimes called a desktop switched Ethernet. In the case of segments, the is replaced with a . Allowing simultaneous conversations to occur as the frame only reaches the recipient.
In the future, full duplex data communication will be more frequent allowing data to be sent and received at the same time leaving a collision free environment.
The main advantages in a LAN are that:
- All the data is stored on a file server which is backed up using tape daily.
- Anyone in an organization can access information on the server simultaneously.
- Information can be accessed from the other side of a large building.
The main disadvantages in a LAN are that:
- They can be very expensive
- If the file server is damaged then the whole company may suffer
- The speed may be dependent on the topology of the network (Explained below)
Types of Topology
The topology of a network refers to the configuration of cables, computers, and other peripherals.
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Linear Bus is when file server, workstations and peripherals are connected to the main run linear cable (show below).
- Star network is when each node is connected to a central hub or concentrator. Data on a star network passes through the hub or concentrator before continuing on to its destination. The hub controls all functions of the network. It also acts as a repeater for the data flow. Common with twisted pair cable, coaxial cable or fibre optic cable can also be used.
- Star-wired ring is basically the same as the star network. However the nodes are also connected, in a ring shape, allowing them to communicate.
- Tree network is combination of linear and star topologies.
Development of networks
Recent development has made the transfer of large data quicker. Over the years many things have been changed.
- Previous coaxial copper medium has been replaced by fibre optics.
- Networks have become wireless.
- Network diameters have increased in size and quality.
Wireless Network Advantages
- Flexibility: within radio coverage, nodes can communicate without further restriction. Radio waves can penetrate walls.
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Planning: wireless ad hoc networks allow for communication without planning. Wired networks need wiring plans.
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Robustness: wireless networks can survive disasters, if the wireless devices survive people can still communicate
Wireless LAN disadvantages
- Lower bandwidth due to limitations in radio transmission (1- 10 Mbit/s) and higher error rates due to interference
- Cost: Ethernet adapter versus wireless LAN adapters
- Proprietary solutions: slow standardization procedures lead to many proprietary solutions only working in an homogeneous environment
- Safety and security: using radio waves for data transmission might interfere with other high-tech equipment
Networks provide businesses and organizations many ways to access and exchange information internally and externally. Communication is vital with customers and employers so all the different types of networks are also vital.
Transactional Technologies
There are several types of transactions but the most common transaction is the process that takes place when a cardholder makes a purchase with a credit card.
Since these transactions are dealing with money they must be secure so companies have developed secure transaction technology.
The Credit Card
The first credit card was issued in 1950 at the Diners’ Club in the United States. American Express followed and issued their card in 1958.
A credit card is a thin plastic card, usually 3-1/8 inches by 2-1/8 inches in size that contains identification information such as a signature or picture, and authorizes the person named on it to charge purchases or services to his account -- charges for which he will be billed periodically. Today, the information on the card is read by (ATMs), store readers, and and Internet computers. Most cards now come with a chip as standard for security.
The numbering system for phone companies, gas companies and department stores is different. However the main numbering system used by credit card companies is the ANSI Standard X4.13-1983.
The number on the credit card is separated into 4 sections.
The number may vary depending on the company. (Shown below)
American Express - Digits three and four are type and currency, digits five through 11 are the account number, and digits 12 through 14 are the card number within the account and digit 15 is a check digit.
Visa - Digits two through six are the bank number, digits seven through 12 or seven through 15 are the account number and digit 13 or 16 is a check digit.
MasterCard - Digits two and three, two through four, two through five or two through six are the bank number (depending on whether digit two is a 1, 2, 3 or other). The digits after the bank number up through digit 15 are the account number, and digit 16 is a check digit.
The stripe on the back of a credit card is a magnetic stripe, often called a magstripe. The magstripe is made up of tiny magnetic particles in a plastic-like film. A magstripe reader can read the data on the strip.
If the ATM isn't accepting your card, your problem is probably either:
- A dirty or scratched magstripe
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An erased magstripe (The most common causes for erased magstripes are exposure to magnets and exposure to a store's (EAS) tag demagnetizer.)
Information on the Stripe
There are three tracks on the magstripe. Each track is about one-tenth of an inch wide. The ISO/IEC standard 7811, which is used by banks, specifies:
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Track one is 210 per inch (bpi), and holds 79 6-bit plus parity bit read-only characters.
- Track two is 75 bpi, and holds 40 4-bit plus parity bit characters.
- Track three is 210 bpi, and holds 107 4-bit plus parity bit characters.
Only track one and two are used. Track 3 is a read/write track that contains PIN, country code etc.
The information on track one is contained in two formats: A, which is reserved for proprietary use of the card issuer, and B, which includes the following:
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Start sentinel - one character
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Format code="B" - one character (alpha only)
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Primary account number - up to 19 characters
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Separator - one character
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Country code - three characters
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Name - two to 26 characters
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Separator - one character
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Expiration date or separator - four characters or one character
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Discretionary data - enough characters to fill out maximum record length (79 characters total)
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End sentinel - one character
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Longitudinal redundancy check (LRC) - one character
The format for track two, developed by the banking industry, is as follows:
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Start sentinel - one character
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Primary account number - up to 19 characters
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Separator - one character
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Country code - three characters
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Expiration date or separator - four characters or one character
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Discretionary data - enough characters to fill out maximum record length (40 characters total)
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LRC - one character
Authentication
There are three basic methods for determining whether your credit card will pay for what you're charging:
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Merchants with few transactions each month do voice authentication using a touch-tone phone.
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Electronic data capture (EDC) magstripe-card swipe terminals are becoming more common -- so is swiping your own card at the checkout.
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Virtual terminals on the Internet
Smart Cards
Smart cards were first used in 1984 in France. A smart card has a microprocessor built into the card. The chips in these cards are capable of many kinds of transactions. For example, you could make purchases from your credit account, debit account or from a stored account value that's reload able. The enhanced memory and processing capacity of the smart card is many times that of traditional magnetic-stripe cards and can accommodate several different applications on a single card.
Credit cards relation to business and organizations.
Basically credit cards are used by customers and employees. Large transactions of money can be made with the use of bank accounts and these are used by businesses for all their need.
Automated Teller Machine (ATM)
From an ATM you can, via bank cards i.e. credit cards, so that you:
- Can get a bank statement
- Can withdraw money
- Can top up your phone (new feature)
How Does an ATM work?
Basically, an ATM is a data terminal with two input and four output devices.
Like any other data terminal, the ATM has to connect to, and communicate through, a host processor. The host processor is analogous to an (ISP) in that it is the gateway through which all the various ATM networks become available to the cardholder.
EFT (Electronic Funds Transfer) and Transaction Security Modules
Electronic Funds Transfer is a system which electronically moves data representing money between accounts or organizations without having to actually move the money (i.e., paper, gold, etc.). Organizations can use EFT when doing business, for many reasons i.e. buy new computer components.
The Transfer of money for businesses is usually a large amount thus it has to be secure. Security modules use encryption to make them secure. Such as the Incognito TSM 110 which is designed specifically for financial transaction applications and EMV terminal support. Ideally suited for use in EFTPOS (Electronic Funds Transfer at Point of Sale) terminals
Overtime, transactions i.e. money transfers have become more secure with the use of cryptographic technology. The use of security modules such as the Incognito TSM 110 has made it easier for businesses to transfer money without worrying.
However, the money being transferred may have an illegal purpose which at the moment cannot be stopped.
- The use of smart cards enables higher levels of encryption and security.
- The use of security modules for EPOS and EFTPOS also enables higher levels of security
- ATM machines around the world allow access to money at any time, not forgetting that the credit card allows the purchasing of services and goods all around the world.
Overall, business transactions are becoming secure, however, as every technology can be hacked into this is no different. Businesses use systems like EPOS because they are faster and cheaper in the long term. Cash systems are becoming more secure yet more available around the world.
Use of ICT in REPORT
I also used Google to search for transactional technology (shown below)
This was also carried out for network technologies and the internet.
However, (above) “+” sign was used to narrow the search and get better results.
Sources:
http://www.prism.co.za/
http://www.howstuffworks.com/
http://www.ewart.org.uk/it/network/topology/topology.htm/
http://www.webopedia.com/TERM/I/intranet.html