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Published by Cambridge Paperbacks, 2019-11-21 09:38:28

Session 2

Global Information





Technology





Session 2











Presented





by





Dr Allen Brown

Telecommunications and Computer Networks



• These are integral components of almost every


company. Data is a valuable assit.



Networked Enterprise Components

























• A simplified computer network will has clients


(users) and a server (a PC with all the apps on)


• The connection between them is the standard is the


swisted pair Cat5, Cat 6 or Cat 7 cable.


• The difference between them is the amount of data


traffic they can carry – Cat 7 carries up to 600Mbps.






RJ45 LAN connector














1

• It’s not uncommon to see a server with many of these


cables – patch panel.





























• When you added a printer to a network, connect


directly to the server or the router.


• The server software will decide which clinet can


access the printer.


• In an enterprise there will be a LAN administrator


(some of you may find yourselfs as administrators in


the future).


• Their function is to ensure the smooth running of the


LAN.


• Define the range of services provided by the server.


o Web servers: used to store the file and code used


to make up Web pages.






2

o Mail servers: stores all email accounts which


clients can access.


o File servers: make files accessable for


downloading and storage to the clients.


• All the apps will be on the server. Very easy to updata


with only one copy which the clients can access.






Types of networks



• There are several configurations of networks


depending on their requirements.



• PAN: Personal Area Network, in the home with

several devices connected together to exchange


data. Low cost



• LAN: Local Area Network, minimum of 2


computers to thousands all within the same

building.



• WAN: Wide Area Network, a network where data


is transmitted over large distance.

o Connecting several LANs together which are at


different locations (global).








3

• WLAN: Wireless LAN, a LAN which has provision


for connecting clients using Wi-Fi.






















o As you can see in this diagram there is a


Wireless Access Point connecting a LAN and a


WLAN.


o Very similar to a router.























o As you can see in this Netgear R6220 AC1200


smart router, LAN connectors and a WAN


connector in yellow – going to the server.







4

o Allows communication with labtops which


these days only have Wi-Fi.


• MAN: Metropolitan Area Network, connecting


LANs with in a 30 mile city.






















o Normally use an Internet Service Provider for


the communications channel to connect


several LANs.


o It’s common practice for a university to have


its own MAN connecting the different


departments.


o Also use WiMAX as a wireless technology for


communications of LANs.


o The technology often used is the


synchronous optical network (SONET).


o The OC3 for a MAN can carry 155 Mbps.





5

o Multiprotocol Label Switching (MPLS) which


allows a variety of comms technology to be


used.


SAN Options




• DAS: Direct Attached Storage.





















o SCSI Small computer system interface


o Block level storage, instead of whole files of


data being transferred, only smaller blocks of


data are used.


o Not easy for Server 1 to access the DAS on


Server 2.


• NAS: Network Attached Storage



















6

o Acts like a File Server.


o Much slower access that SCSI.


• FC: Fibre Channel

























o Found in enterprises.


o Allows fast block level storage which is more


efficient that file level storage.


o Communication between Servers to the FC is


through a HBA.


o Expensive to imprelemt.


• FCoE: Fibre Channel over Ethernet.

























7

o Much cheaper solution than FC by itself.


o Can be The fibre channel storage can be


accessed directly from the servers through the


FCoE.

o To be found in large enterprises.



• iSCSI: Internet Small Computer System Interface
























o Data transfer in IP packets.


o Allow block level access.


o Cheaper solution that previous designs.

o Suitable for a small enterprise.


o Performance is not as good as FCoE.




• VPN: Virutal Private Network, when you extend a


LAN over the internet to a PC in a remote location.


o For a person to share their PC resources with


others.





8

o Very useful for a very, very small business


where there is a need to communicate with


customers.


o To set it up, you have to do port forwarding.





Advantages of Network Environment



1. Enhanced communication


• Instant messaging to allow people to see and


talk in real time.


• Send files to other people wherever they are


located globally.


• Access to a vast amount of information


including news and current events.


2. Convenient resources sharing.


• Needed in large companies who share


information and resouces.


• Shared through networks.


3. Easy file sharing


• Sharing data is very importatnt.



• A company may wish to show its current stock


levels with customers.




9

• Makes ording from a catalogue easy.


4. High flexibility


• Changes and expansion can be implemented


without disruption – software updates.


• New technology can be introduced to


imporove the speed of communications.


5. Relatively low cost.


• Once a system is in place, the cost of


maintence is relatively low and updates can be


implemented without too much expense.


6. Cost efficienty


• So many competitively costing apps on the


market which can be stored on a server and


accessed by the clients on the network.


7. Memory capacity


• Making files available to clients on the network


is easy to achieve as they are stored on the


network had drives.


• As the need for more memory increases, it’s


easy to add more hard drives without


disrupting the system.






10

8. Employment


• In order to maintain computer equipment for


enterprises expert employees are required to


perform this task.


• This offers employment for computer science


graduates who will also be responsible for


upgrading the equipment as the need arises.







Business Uses of Internet



• There is a saying in Silicon Valley,













Here is a desk Here is a Now make a


computer business



• There are huge opportunities for business


enterprises employing the internet.


• There are six phases


1. Identify your market.









11

2. Can your provide a service or product for that


market? Have you got the passion to do it?


3. Costing the service or product.


4. Getting the finance to support your start-up, you

will need a convincing spreadsheet.


5. Creating the service or product.


6. Marketing and selling your product or service


using the internet.



Open discussion on



new business opportunities





using the internet



































12

Distributed Computing



• It is customary to think of a single computer exchanging


data with other computer, but doing its own


processing.


• Alternative concept is to have several computers


processing the same data togeter – distributed


computing.



Grid Computing























• To have several computers in different locations


performing the same mathematical calculations –


executing the same model.


• Example the Navier-Stokes equation,




2
[ + ∙ ∇ ] = ∇ − ∇ + ∆




• can be a huge vector with hundreds of elements.




13

• This equation is used to model fluid flow, weather,


rocket fuel combustion…


• Normally need a supercomputer to perform the


calculations.


• A cheaper solution is to use a grid of PC working in


parallel.


• Grid computing is a computer network in


which each computer's resources are shared


with every other computer in the system.


• Processing power, memory and data storage


are all common resources that users can


access for specific computational tasks.


• A grid computing system can be as simple as a


collection of similar computers running on the


same operating system.


• Alternatively a more complex networked


systems comprises disparate computer


platforms.


• In the ideal grid computing system, every


resource is shared, turning a computer


network into a supercomputer.






14

• With the right user interface, accessing a grid


computing system would look no different


than accessing a local machine’s resources.


• Every computer in the grid would have access


to enormous processing power and storage


capacity.


• There is some interesting work going on in


the University of Antwerp in Belgium.


• They have a PC called Fastra.


• Their PC development is applied to


tomography.






























• Four graphics cards containing 8 GPUs as you


can see in the image.


• Needs a beefed-up power supply.






15

• It’s made from consumable hardware – off


the shelf components.


• Cost < €4,000


• One hour computation using a PC cluster →


30 seconds.


• GPUs are designed to perform this type of


calculation very efficiently.


11 12 13 ′



( 21 22 23) ( ) = ( ′)
31 32 33 ′





















• It can be used to translate the position and change the


position and shape of an object in 3D space.


• Also rotation and stretching and shearing.


• Every 3D object is made from many little objects like


this one and each needs to be processed.










16

GSM Global System for Mobile


























• This is a simplified block diagram for GSM.


• Looking into each of these blocks we find.

























o BTS – Base Transceiver


System →


o BSC – Base Station

Controller


o OMC – Operations and


Maintenance Centre,






17

monitor the performance of the

network.


o MSC – Mobile Switching Centre

o HLR – Home Location Register


o VLR – Visitor Location Register,


used for roaming needs.

o AUC – Authentication Centre,


checking users by the SIM numbers.

o PSTN – Public Switched Network,


land line telephones.


o Frequency bands 900MHz and 1.8 GHz







3G, 4G & 5G technologies



• Technologies for connecting mobiles to the network


(G stand for Generation)


• In addition to voice, other data formats are


transferred, MP3 audio, photos, video and storage.


• Streaming audio and video.


• Generally 4G is faster than 3G and offers more


storage.


• 5G should proide download speeds up to 20 Gbps.







18

• The latency time should only be 1 ms.


• Likely to used in self-driving cars.


• 5G will allow more simultaneous connections – the


number of mobiles in the workd is increasing.



VoIP Voice over Internet Protocol



• Using the internet for voice telephony.


• Uses a CODEC to convert speech into packets which are


then sent acorss the internet.


• Much cheaper than internation telephone calls.


• Skype was one of the first.


• The quality (QoS – Quality of Service) varies to how


much trafic there is between source and destination.


• However apps like WhatsApp uses Extensible Messaging


and Presence Protocol (XMPP) for streaming XML data.



• Seems to have superior performace to VoIP.



IPTV Internet Protocol Television



• Delivering television over the internet.


• Streaming media – client can watch material without


waiting.


o Live television





19

o Time-shifted television


o Video on demand


• Making big inroads into traditional terrestrial, satellite and


cable TV.


• Many international providers.


• In the UK Netflix is gaining in


popularitym choose any movie you


want to watch !


• To a smaller extend, Amazon is making some headway in


the UK.


• BBC is now under threat from IPTV, its left-wing bias in


reporting news, cannot be relied on as a true unbiased


news media.































20

Electronic Commerce Systems



• The internet is now an indispensible tool for e-


Commerce.


• Networked computers are also indispensible for


any size business.



Introduction to e-Commerce



• Broadly defined as the process of buying or


selling of goods or services using an electronic


medium such as the Internet.




























• eCommerce refers to the paperless exchange


of business information using the following


ways:



• Electronic Data Exchange (EDI)







21

• Electronic Mail (e-mail)


• Electronic Bulletin Boards


• Electronic Fund Transfer (EFT)


• Other Network-based technologies


Features



• Non-Cash Payment: enables the use of credit

cards, debit cards, smart cards, electronic fund


transfer via bank's website, and other modes of

electronics payment.


• 24x7 Service availability: automates the


business of enterprises in the provision of

services to customers. Available anytime,


anywhere.


• Advertising - Marketing: − Increases the reach

of product advertising. Better marketing

management of products and services.



• Increased Sales: Orders for the products

generated anytime, anywhere without

automatically. Boost to existing sales volumes.



• Support: Provides pre-sales and post-sales

assistance leading to better services for

customers.








22

• Inventory Management: Automates inventory

management. Reports get generated instantly

as required - easy to maintain.


• Communication improvement: Provides ways


for faster, efficient, reliable communication

with customers and partners.



Potential Problems


• Possible lack of system security, reliability or


standards.


• Many countries do not have a robust network


bandwidth.


• If a company does not have eCommerce –

exclusion from the market.


• Difficulties integrating ecommerce software or


website with existing applications or databases.


Business Models



• Business to business























23

• Business to consumer



















• Customer to customer



















• Consumer to business





















• Payments through credit or debit cards or direct


bank transfer.


• Need to have this embedded in the software.


• The use of PayPal.






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• Major concerns – security and scams.


M-Commerce




• Mobile commerce or M-Commerce – buying and


selling using a mobile.

• Downloading an app which you pay for is an


example of M-Commerce.


• When setting up a payment method, could employ


a payment gateway such as PayPal to handle the


process.


• Advantages


o Can handle huge numbers of sales and is easy


to implement.


o People are more inclined to use mobiles than


PC these days.


o Easy for advertises to embed adverts in mobile


data.


o Many people pay for products in shops using


M-Commerce software.


o Becoming a cashless society - Sweden


• Disadvantages


o Security is always a big issue.





25

o Loss of moble and the possibility of someone


hacking into it.


o Person to person money exchange requires


paper money – cannot be traced – the Black

Economy – no VAT.



Concept of Internet Banking



• Movement away from using cheques for money


payments.


• Almost all bank transactions can be performed


over the internet.


o Money transferred from employer to


employee’s bank account – tax and National


Insurance deducted using PAYE.


• Customers can access their bank details via their


bank’s website.


• A bank is able to advertise all the services it


provides as customers access their account


details.


• First Direct, part of the HSBC group offer


telephone banking – no high stree banks. All


transactions are effected over the telephone.





26

Electronic Payment Systems


• Making an ePayment for goods and services


without the use of paper money.


• Use of smart credit and debit cards


– chip & pin.


• Will accept large amounts of


money transfer – thousands of £ -


used when buying new car.


• Contactless use for purchases under £30.


• In Hong Kong, in common use is


the Octopus card.


• Used for buying everyday


products and services,


transport, food..


• Many shops, have the


facility to credit your


Octopus card – hand


over your HK$ money


and credit is added to your card.


• Word of caution – don’t put too much credit on it,


if lost it’s gone !






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