internet technologies. hardware and software for the internet 2
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Internet Technologies
Hardware and software for the internet
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Web browser software
• A web browser has a user friendly interface• A web browser is know as a client application• It “sees” the World Wide Web (if connection available)• It converts HTML source into a visible page• Plugins extend the browser’s functions, e.g. Flash player
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Browser software
Browsers (Clients)• Chrome• Internet Explorer• Firefox• Mozilla• Sea Monkey• Opera• Safari
Plugins• Flash• QuickTime• Real Media Player• Acrobat readed
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Most modern browsers come with plugins installed
Web browser - plugins
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Opera > Settings > Preferences > Downloads > Advanced
Firefox > Tools > Options > Applications
Firefox Opera
Web browser software
• A Uniform Resource Identifier (URL, can be pronounced “earl”) is a web address, e.g.
http://www.bbc.co.uk
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Security•Use antivirus software, e.g. AVG, Windows, Microsoft Security Essentials.•Use a Firewall, e.g. Windows Firewall, or Zone Alarm•Do not visit unsafe web sites•Keep your web browser updated
Email Software
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Webmail (e.g. Gmail, Hotmail, Yahoo Mail)
Email Clients, e.g. Microsoft Outlook, Thunderbird, Live Mail
Additional features
Web Servers
• A web server can be hardware or software
• It allows you to access the Web
• Web servers also host websites, provide data storage or run applications (e.g. gaming sites, online shopping)
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Server room in CERNA, author: Florian Hirzinger – www.fh-ap.com
Web Servers
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Web server (remote server)e.g. www.bbc.co.uk
Client, e.g. Chrome browser
Internet connection via an Internet Service Provider (ISP)
Data being requested and downloaded to client
Servers can also be set up on any computer to create a local or home network (intranet)
Web Servers
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You can create your own web server on your home computer/laptop. Free software such as WAMP can be used
Webservers
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Transport & Addressing TCP/IP Protocol
Protocols are the agreed way that different systems can talk to each other, sometimes called a 'handshake'. They work a little like a translator does when two people who speak different languages are trying to communicate.
TCP/IP (transmission control protocol/Internet protocol) is responsible for transporting data and making sure it reaches the right address. It consists of four layers (included in every data package that is sent across the Internet):1.Link layer2.Internet layer3.Transport layer4.Application layer5.http://www.youtube.com/watch?v=XGZ0Cao_o_E&feature=related (ip4 ipv6)6.How the TCP/IP Protocol works (link - http://www.youtube.com/watch?v=HOaIqQAeaik&feature=related)7.How the internet works- http://www.youtube.com/watch?v=7_LPdttKXPc&feature=related
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Transport & Addressing TCP/IP Protocol
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Application layer (highest layer/client level)
Contains other protocols including HTTP, HTTPS and SMTP.
The hypertext transfer protocol (HTTP) sends out a request to the client to establish permission to transfer data. The client may be the final destination or just a node on the journey.
In HTTPS, the S stands for Secure and does the same job but ensures a secure connection. This is used in eCommerce, banking websites.
Simple mail transfer protocol (SMTP) is the main protocol for the transfer of email. POP (post office protocol) and IMAP (Internet message access protocol) access mail servers.
Transport layer Establishes communications between hosts and moves the package towards its destination
Internet layer Focuses on targeting the IP address
Link layer (lowest layer) Deals with hardware, navigating through the myriad of routers, servers and other machinery to reach its destination.
Email Servers
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• POP3 Servers (POP=Post Office Protocol) When mail is downloaded, it is normally deleted on the remote mail server
• IMAP Server (Internet Message Access Protocol)Your webmail and client email synchronise so no matter what system you are using, you always see the same email.
Email Servers
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Remote email servers
Web mail
Microsoft OutlookUsed with permission from Microsoft.
POP3 Servers (POP=Post Office Protocol) When mail is downloaded, it is normally deleted on the remote mail server
IMAP Server (Internet Message Access Protocol)Your webmail and client email synchronise so no matter what system you are using, you always see the same email.
Routers
• A router forwards data (data packets) across computer networks.
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Wireless router (Local Area Network - LAN)
Routers
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Proxy Servers
A proxy server sits between your computer and the Internet•It can keep you anonymous, mainly for security•It can log usage by different users, e.g. in an organisation•Viruses/malware can be scanned giving added security•Dangerous sites can be blocked, e.g. for parental controls.•It can cache (store) web pages from web servers across the internet making your browser faster•It may improve the overall performance of web browsing•Example http://ww.opendns.com
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Proxy Servers
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OpenDNS provide a free proxy server available for home users. It is popular with schools and organisations (link)
To set up, you need an account and need to set the router settings to the proxy settings
Web Functionality
WEB 1.0• Web 1.0 - this is passive web. The webmaster has to update the website with very
little input from the user.• Web 1.0 - this is simple place to store information.• The worldwide web has been evolving over the past 20 years since in 1991 after
Tim Berners-Lee invented the worldwide web. • Web 1.0 - is yesterday’s users looked for information. • Web 2.0 - today’s users looking for experience as well as information
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http://www.bbc.co.uk/news/world-asia-16095369 - Turkmenistan
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• Even today, some countries restrict web access, e.g. Turkmenistan. Social networks, including Facebook, Twitter and YouTube, are blocked. This censorship was extended to Gmail in 2012, reports RSF, which lists Turkmenistan as an "Enemy of the Internet".
Web restrictions
http://www.bbc.co.uk/news/world-asia-16095369 - Turkmenistan
WEB 2.0• Web 2.0 is a term to describe how web pages are used.• It allows users to interact in social media and be creators of content in a virtual
community (Web 1.0 only allows passive viewing)• Examples of Web 2.0 include social networking sites, blogs, wikis, folksonomies
(tagging/classifying), video sharing sites, hosted services, web applications, and mash-ups (merging content from several web sites)
23What is the difference between Web 1.0 and Web 2.0?
WEB 2.0• Web 2.0 - web masters share responsibility with the internet audience for keeping a website
informative and engaging. • The user now produces the content of the website, e.g. content, clips on Youtube, blogging,
tagging, social networking social bookmarking,• Web 2.0 - is a dynamic place where people gather and interact. Web 2.0 gives you
customiseable web pages
Examples and uses of Web 2.0• Net Vibes, RSS (RSS feeds automatically comes to your page).
RSS = Really Simple Syndication.• Flickr - subscribe and upload pictures on Flickr• Del.ic.ious - http://www.delicious.com/ - this is for bookmarking web pages• Tagging - likes/dislikes• Google Docs (online applications) and Spreadsheets, Google Maps - e.g. adding a business to
a map
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Examples of WEB 2.0• Facebook
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Blogs
• The word stands for ’web log’ and they’re really online diaries or journals which are frequently updated.
• Anyone can set one up (e.g. Word Press)
• That’s the easy part. • Thinking of something interesting to say each
time you blog is the tricky bit!
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Blogs (Web 2.0)
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Wikis (Web 2.0)
• Wiki – is a website whose content is based on the collaboration of work from many different authors.
• A Wiki allows anyone to edit, delete, or modify the content of the Wiki pages
• Wiki means "quick" in Hawaiian. • Like Blogs, Wiki pages are created by the users
(Web 2.0)
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Web 3.0• Web 3.0 is also known as semantic web. It is the future• Brings meaning to the web but computers are not like human beings yet!• Web 3.0 responds to your individual needs and is intelligent• Links between vastly different databases may be made possible• Computer technology spread everywhere: home appliances, portable
devices, in the car, sat navs, cameras, etc. - all these devices can link up their data
• Intelligence about you is created.• Web 3.0 can then help anticipate and respond to your everyday needs
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Web 3.0• E.g. an online agenda gathers information from your Facebook account
(e.g. friends) , location of friends (GPS), the weather, Google maps, BBC travel news and sets your agenda for the day
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Web 3.0
• Summarise the difference between Web 1.0, Web 2.0 and Web 3.0
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Web 1.0Web 2.0Web 3.0
Online Applications
• Applications running in a web browser
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Online Applications
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Web Architecture
What you need to connect to the Web
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Internet Service Providers (ISPs)• An Internet Service Provider (ISP) is a company that offers access to the
Internet (normally broadband) and to e-mail, usually for a monthly fee.
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Internet Service Providers(ISPs)
Examples - these companies provide broadband internet connections
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Internet Service Providers (ISPs)Types of Broadband
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• Digital Subscriber Line (DSL) is a technology that delivers broadband over your phone line (copper) to be used in the home or office.
• Asymmetric Digital Subscriber Line (ADSL) - similar to DSL - can download web pages and files at fast speeds
• 3G and 4G Mobile Broadband: 3G speeds are enough low quality YouTube, Skype calls, and other low-level applications and 4G is suitable for streaming HD video, real-time gaming and streamed multimedia content at faster speeds.
• Satellite Broadband - you must have a dish antenna; be used almost everywhere in the UK but satellite transmission may be affected by weather conditions; it can be quite expensive compared with other types of broadband.
Faster broadband:• Cable Broadband is delivered through a fibre optic cable. You can only get
cable broadband if a company has cabled your street. Cable providers include VirginMedia and BT - speeds of up to 76 MB/s are possible - http://www.money.co.uk/broadband/cable-broadband.htm
Internet Service Providers (ISPs)
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• People in towns and cities are more likely to get faster cable broadband - the telephone equipment, cabling and exchange points will be maintained and upgraded regularly
• If you live in the countryside it's not cost effective to maintain a cable or network for a handful of customers - ADSL users will probably use the same phone cables that have been there for years.
• Broadband information: http://www.uswitch.com/broadband/guides/
Web Hosting Services
• Hosting: provide online storage, e.g. for website• Domain names: provide domain names, e.g.
www.mydomain.com• Email server: you can have your own email, e.g.
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The Worldwide Web
The worldwide web (or “Web) runs on top of the Internet (a much larger network). The Web allows pages to be linked together by hypertext links, enabling the user to move easily between pages. You need a web browser (e.g. Chrome) and an internet service provider (e.g. Virgin Media) to provide you the connection to the “Web”
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The first web server (1991)
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The first web browser (1993)
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Domain Structure
• Domain name: The specific address of a computer on the Internet, e.g. microsoft.com
• Uniform Resource Locator (URL): – http://www.microsoft.com/faqs.html
• Internet protocol (IP) address - Every computer that communicates over the Internet is assigned an IP address that uniquely identifies the device and distinguishes it from other computers on the Internet, e.g.
– 192.168.1.1
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Domain Name System
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Because the Internet is based on IP addresses, not domain names, every Web server requires a Domain Name System (DNS) server to translate domain names into IP addresses
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The Universal Resource Locator (URL)
Each page of information on the web has a unique address called the URL (pronounced “earl”) which is the web address at which it can be found, e.g.
http://www.nortcoll.ac.uk/aboutus.html
Domain Structure
http:// www nortcoll ac.uk /aboutus.htmlMethod:Hypertext Transfer Protocol (HTTP)
Type of page:worldwide web
Resource name (domain name, where the page is located)
Top level domain, ac = academic institutionaboutus.html = file name or web page
Domain Name Registrars
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Domain Name Registrars
• A company, e.g. uk2.net, that provides domain name registration services.
• Maintains databases mapping domain names to IP addresses
• Propagates new domain names across the internet (e.g. takes up to 24 hours)
• Look up a registrant (http://domainhelp.tucows.com/whois)
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Some links
• Internet basics (link)• Different type of broadband (link)• How to get access to Web/ISPs (link)
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