Introduction to the Internet PDF

INTERNATIONAL & ACCESS FOUNDATION PROGRAMMES COMPUTER SCIENCE Semester I Part 2 Introduction to The Internet Nevan Bermingham What is a Computer? “A computer is a programmable machine designed to sequentially and automatically carry out a seque...

INTERNATIONAL & ACCESS FOUNDATION PROGRAMMES COMPUTER SCIENCE Semester I Part 2 Introduction to The Internet Nevan Bermingham What is a Computer? “A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations” "equipment that operates automatically to process data“ – UK Data Protection Act 1998 Exercise. What do we mean when we refer to Information Technology? What are the components of that make up Information Technology? What do we mean by I.T.? Information technology (IT) “is a branch of engineering dealing with the use of computers and telecommunications equipment to store, retrieve, transmit and manipulate data” The Information Technology Association of America has defined IT as "the study, design, development, application, implementation, support or management of computer-based information systems" Computing Evolution Difference Engine - 1822, Charles Analogue Physical Babbage AKAT-1 was the world's first transistor differential analyzer - 1959 IBM 1401 - 1959 IBM 5150 - 1981 Electronic HP Compaq tablet PC – 2003 Digital Binary Integrated Circuit All electronic computers operate by performing Binary calculations. Basic Model of a Computer High Level View of a Computer Applications Operating System Compu Keyboar ter Interne d Hardw t Mouse are Screen The Internet The Internet is a global system of interconnected computer networks It is a network of networks that consists of millions of private, public, academic, business, and government networks. Documents (WWW) and eMail The History of the Internet 1960’ US Defence Forces - ARPANET s 1980’ Internet Protocol Suite (TCP/IP) s a world-wide network of fully interconnected computers CERN – 1990’ HyperText Transfer Protocol (HTTP) s HyperText Markup Language (HTML) the first Web browser (Sir Tim Berners-Lee) Web 2.0 – YouTube, On line gaming, Media 2000’ (Netflix), s Video Conferencing, Social Media, Blogging, On line Gambling, Banking, Shopping. Group Exercise: What do you think “The Internet Means? Describe what does the Internet mean to you? Think of it under the following headings: 1. Different ways you use the Internet 2. How the Internet has changed how you work or play. 3. Are there positives or negatives of the Internet in your own life 4. And finally, what do you think the next advancement will be in the IT & Computer Science space? The Internet and its Impact Lets have a look at some statistics about the internet. Here are some recent statistics that you probably were not aware of, to help you gauge the impact and capacity of the Internet…. Internet Stats 2018 Overview Internet Stats 2018 Internet Users Around 40% of the world population has an internet connection today In 1995, it was less than 1%. The number of internet users has increased tenfold from 1999 to 2013. The first billion was reached in 2005. The second billion in 2010. The third billion in 2014. Internet Stats 2018 Social Media Internet Stats 2018 eCommerce https://www.itu.int/en/ITU-D/Statistics/Documents/facts/ICTFactsFigures2017.pdf Why do devices matter? “The iPhone rules”myth? Internet Growth https://www.ncta.com/platform/broadband-internet/behind-the-numbers-growth-in-the-internet-of-things-2/ Some Other Facts About the Internet  The computer in your mobile phone is 1,000,000 times cheaper, a 1,000 times more powerful, and 100,000 times smaller then than one computer at MIT in 1965.  By 2020, the mobile phone/devices will be the worlds primary connection device to the internet.  Gartner Says 4.9 Billion Connected "Things“ (devices including mobile, fixed, cars, wearables, etc) will be in use in 2015  Social networking is the fastest growing part of the Internet. As of January 2018, Facebook alone had 2.2 billion monthly active users. Facebook was the first social media website to reach over 1 billion accounts.  YouTube users in 2018 have surpassed the 1.5 billion mark, making YouTube the most popular website for viewing and uploading videos in the world  In 2018, 90% of businesses are using social media actively Group Work (Groups of 3 or 4) Examine:- 1. What trends do you think will happen over the next few years with technology & internet? 2. What will be “big”? 3. What are the challenges? 4. Pick your groups “Top 3” Gartner Predicts…  Consumers Favour Visual and Voice Search - By 2021, early adopter brands that redesign their websites to support visual and voice search will increase digital commerce revenue by 30%.  Legitimised Cryptocurrencies - By the year 2020, the banking industry will derive $1B of business value from the use of blockchain-based cryptocurrencies.  Increased Fake News & Counterfeit Reality - By 2020, AI-driven creation of “counterfeit reality,” or fake content, will outpace AI’s ability to detect it, fomenting digital distrust.  Bots Take Over - By 2021, more than 50% of enterprises will spend more per annum on bots and chatbot creation than traditional mobile app development. Gartner Predicts…  IoT in Everything - By 2020, IoT technology will be in 95% of electronics for new product designs.  Assume IoT Security Vulnerabilities - Through 2022, half of all security budgets for IoT will go to fault remediation, recalls and safety failures rather than protection. Internet Changing History? http://www.ted.com/talks/clay_shirky_ how_cellphones_twitter_facebook_can _make_history.html How does the Web Work? DOMAIN NAME SERVER (DNS):- CONVERTS WWW NAME INTO Type Web 1 Address NUMBERS (AN IP ADDRESS) Find Web Server 2 Location 3 Request Page 5 Show Web Page Send Page to 4 Ireland Webservers Disk Array Rack Mounted Servers (Computer) Rack Mounter Servers Domain Name Server Where do you see this in Windows? ICANN ICANN was created on September 18, 1998 The Internet Corporation for Assigned Names and Numbers Formerly known as Internet Assigned Numbers Authority (IANA) Non-profit organization that is responsible for coordinating the maintenance of several databases of IP Addresses  Responsible for the Internet's global Domain Name System (DNS) IP Addresses (IP Version 4) IP addresses are Dots separate the sections written in dotted decimal format. Four sections are 10.1.1.1 separated by dots. Each section Each section contains a number contains a number between 0 and 255. between 0 and 255 IP Addresses 10.1.1.1 32/4 == 8. 28 = 256. 00001010 00000001 00000001 00000001 8 8 8 8 But, computers 32 number starting at 0, so to make a Each 8 digit group space of 256 represents a number between 0 and 255 numbers, we number from 0 to 255. IP Addresses Each device on a network is assigned an 10.1.1.1 IP address. Each IP address has 00001010 00000001 00000001 00000001 two fundamental parts: The network portion, Network Host which describes the physical wire the device is attached to. The host portion, which identifies the host on that wire. Limit of IP v4 4.3 billion addresses Only 3.7 billion of these are actually usable Growth needs a move to IPv6 How does the Internet Work? Type Web 1 Address DOMAIN NAME SERVER (DNS):- CONVERTS WWW NAME INTO NUMBERS (AN IP ADDRESS) Find Web Server 2 Location IP Address (Internet Protocol) 137.254.16.113 How does the Internet Work? Packet Data eMail A THE INTERNE T B How does the Internet Work? A Data is broken eMail down into “Packets” THE INTERNE T B How does the Internet Work? eMail A Header Data THE INTERNE T B How does the Internet Work? eMail A Header Data Block Number, The Sender, The Destination THE INTERNE T B How does the Internet Work? eMail A Header Data Block Number, The Sender, The Destination THE INTERNE T B How does the Internet Work? eMail A Header Data Block Number, The Sender, The Destination THE INTERNE T Data is Recombined B How does the Internet Work? A B C Data Packets How does the Internet Work? A Data Packets A How does the Internet Work? B Data Packets B How does the Internet Work? C Data Packets C Traditional Circuit Switching Uses dedicated physical path (circuit). Ordinary voice phone service is traditionally circuit-switched. The telephone company reserves a specific physical path to the number you are calling for the duration of your call. During that time, no one else can use the Packet Switching Circuits  Small units of data called packets are routed through a network based on the destination address contained within each packet.  Uses Headers for error checking, sender and destination address.  Network has built in “intelligence” – it knows how to best route the data.  Its “disaster tolerant” – it will reroute data.  Error checking - Only send the missing packets if one is lost  Breaking communication down into packets allows the same data path to be shared among many users in the network => More efficient Why Use Packet Data? More efficient:- does not use one line that is dedicated (called a “circuit switched” network). Multiple messages can be sent at the same time to different destinations. The network picks the best and most efficient route (called “network intelligence”). There are many paths data can travel => damage to a part of the network does not hinder its overall operation. If one packet is lost or damaged, only that one part needs to be resent => more efficient. To Recap – The Internet.... The key components of the Internet are: 1. Its a Global Packet Switched Network Your data is broken down into smaller blocks and sent individually, but not necessarily along the same route 2. Its a Network of Networks  Many networks connected to other networks, and each network knows who it is connected to 3. The World Wide Web (WWW) uses the Internet to send Webpages. Further Reading & Resources www.ithistory.org http://www.centerspan.org/tutorial/net.htm