Chapter VII

Internet services

1-Introduction:

  1. As we have explained in previous networking chapter, Internet is a huge global telecommunication network that comprises all the world existing telecommunication networks without exception.
  2. Internet can be compared to the global transportation network that includes all networks of ground transportation, air transportation and water transportation including rivers lakes and oceans.
  3. Many services use global transportation network to move people, animals and merchandise and many services use the Internet to move information in different forms.
  4. Because of the complexity and diversity of these services, several agencies were created to oversee the standards that synchronize the well working environment of the internet body with all its services.
  5. These agencies include the following:
  6. IETF (Internet Engineering Task Force) controlled and financed by the NSA (National Security Agency). ITEF consists of volunteer members who develop Internet standards or RFCs (Request for Comment) that control Internet operational technology.
  7. W3C (World Wide Web Consortium) is a member agencyFounded and headed by the web inventor Tim Berners-Lee. Its role is to develop and promote standards for the Web to lead it to its full potential.
  8. IEC (International Electro-technical Commission private non-profit agency that prepares and publishes international standards for electronic and electrical technologies.
  9. ISO (International Standardization Organization) based in Geneva (Switzerland) prepares and promotes international commercial and industrial standards.
  10. VeriSign authentication services: (Symantec Corporation): Operates a diverse array of network infrastructure, including:
  11. Two of the Internet’s thirteen root name servers.
  12. the generic top-level domains for .com and .net
  13. A variety of security services:
  14. Digital certificates considered as electronic ID for businesses.
  15. Payments processing.
  16. Managed firewalls to mobile call roaming.
  17. Toll-free call database queries.
  18. Downloadable digital content for mobile devices.

2-The purpose of this chapter is to explain the most important of these services and the possibility to use them in business.

3-Despite the fact that every Internet service has its own protocol: http, ftp, pop, smtp, imap, etc… these services must abide by the Internet protocol TCP/IP as well.

4-This condition implies that every service has dual loyalties. (Loyal to 2 protocols).

5-Email @

1-Introduction:

  1. Electronic mail was known and used long before the Internet.
  2. Electronic messages using the Morse code and the telegraph technology early in the 19th centurywere labeled as electronic mail.
  3. Many computer and telecommunication experts believe that the need for improved electronic mail contributed effectively in the creation and development of the Internet itself.

2-Early Email systems:

  1. Many attempts to developing network email systems resulted in some of the following technologies specifications:
  2. Network should have compatible devices
  3. Networks should be similar (same topology)
  4. Both sender and receiver should be online to be able to send and receive.=
  5. Address and protocol were specific to each network

3-Modern email evolution

  1. After the creation of the ARPANET by the Department of Defense and the important military need of fast mailing system the above limitations were not acceptable and soon an interoperability mailing system was born in 1971 using ARPANET computer network.
  2. This system was based on the work of Ray Tomlinsonwho is credited with using the sign @(commercial @)for the first time to separate the name of the subscriber from the name-address of the machine.
  3. Tomlinson system on the ARPANET is the forerunner of modern email service that uses Internet pathways and Internet technology.

4-Modern Email technology:

  1. Modern email service is based on “store-and-forward” technology.
  2. Email messages are coded using ASCII format.
  3. Email service provider or Internet service provider (ISP) maintain 2 mailboxes for each subscriber: One for the incoming mail and another for the outgoing mail.

5-Email protocol

  1. Sent emails use a protocol known as SMTP (Simple Mail Transfer Protocol) which is used only to deliver your sent emails to the servers of their recipients.
  2. To get incoming mail from their mailboxes, subscribers use one of two available protocols: POP (Post Office Protocol) or IMAP (Internet Message Access Protocol)
  3. POP is a simple protocol that allows you to:
  4. Access the mailboxes and download emails to your computer (all available emails together) which allows you to leave the Internet connection and read your emails at your ease. The latest version is POP3.
  5. Messages must be deleted with the possibility to leave copies on the server.
  6. Too many copies left will result in your mailboxes being full and mail reception denied while the boxes are not emptied.
  7. IMAP is a client server protocol that allows emails to be received and held by the server of your ISP (Internet Service Provider) and allows you to:
  8. Work with the server mailboxes as if they were on your own computer.
  9. Download each email message alonefrom the Inbox folder and work offline like POP and the message doesn’t have to be deleted like in POP.
  10. Create folders or mailboxes and classify emails as: “deleted”, “answered”, “sent items”, “flagged”, “favorites”, etc… and file them in organized folders
  11. Access same email from multiple computers

6-Email important features for business include:

  1. CC (Carbon copy): allows you to send the email to many addressees simultaneously. Each addressee will see the addresses of all other recipients.
  2. BCC (Blind Carbon copy): Addresses of BCC recipients are hidden from all other recipients. This feature is extensively used in business and government.
  3. Attachment: The most important feature that enables email to carry along all type of files including multimedia non-ASCII format files.
  4. To be able to travel with plain text ASCII formatted emails, non-ASCII files are converted into ASCII format using a technology known as MIME (Multipurpose Internet Mail Extensions) that consists of a set of standards designed to make attachment exchange via email possible and easy routine.

7-How MIME works?

  1. At the sender end:
  2. Check the email message for the presence of Non-English items and converts them into ASCII code.
  3. Check about the presence of attachments and treats each of them separately converting it into ASCII code.
  4. Inform the receiver end about what to expect to make reverse operation as easy as possible.
  5. At the receiver end MIME performs the reverse operation and displays the message and attachments in their original format.

8-Mailing lists or distribution lists:

  1. This is the most used feature in business and consists of sending email messages simultaneously to a group of people or businesses or a combination of both using only one collective address.
  2. List software is available with MS Outlook and similar application software that enables you to build your own mailing lists.
  3. Businesses and organizations of all types use this feature to build several mailing lists that contribute to improving their productivity.
  4. Many people and businesses abuse mailing lists by selling them as a commodity in the marketing industry and sometimes in the black market.
  5. Customer awareness is highly necessary so that whenever you disclose your email address anywhere for any reason and most importantly in commercial and service businesses, you must ask as of where your address will end up? Or whether it will be part of a mailing list sold in the black market without your own knowledge or your own consent.

9-Email service provider:

  1. There are many ways to get email services that can be summarized by the following:
  2. ISPs (Internet service provider) like AT&T, AOL, Bright house, etc… provide email service as part of other services in the same package.
  3. Webmail provided by:
  4. Web-host services: provide room for email service associated with the website itself.
  5. Free standing website that have its own domain name, servers and database.
  6. Large webmail services each of which has its pros and cons. We will consider the most prominent and popular of them:
  7. Hotmail of Microsoft: lately was configured as part of Windows Live:
  8. First free webmail
  9. Provide as much space as you need (Inbox capacity increase automatically with your need)
  10. No instant notification program offered.
  11. Yahoo mail:
  12. Free Yahoo site webmail
  13. Unlimited storage
  14. No excessive email usage permitted.
  15. Charges for POP access to download incoming mail.
  16. Easy to use interface.
  17. Gmail of Google is the newest webmail with several unique features and offers the following:
  18. Free webmail
  19. 7 gigabytes of storage space
  20. Free POP to download your emails to your PC.
  21. “Gmail Notifier” software notifies you upon arrival of new email.
  22. When using any webmail service it is strongly recommended that you download all emails to your computer instead of leaving them online otherwise your allowed storage will be filled very fast.

WWW (World Wide Web)

1-Web evolution:

  1. The Web service is undoubtedly the most prominent service of the Internet
  2. Many people think Internet and Web stand for the same thing and in fact the population of the web and its too many tools had their astounding effect on Internet popularity especially as a means to get news and information.
  3. Tim Berners-Lee invented the web service over many steps:
  4. 1980 he wrote a program called “ENQUIRE” that link computer information points to each other.
  5. He wrote “Information management” hypertext that became later the WWW. And he published the first web page.
  6. 1990 he declared the invention of

1-The World Wide Web

2-HTML (Hypertext Markup Language) to format web pages

3-A global hypertext and hypertext Graphical user interface browser based on “WYSIWYG” (What you see is what you get) web editor to convert and display HTML tagged web pages.

  1. He performed the first HTTP client server communication using the Internet.
  1. 1993 CERN (European Committee for Nuclear Research) and Tim Berners-Lee donated the Web invention to the world. And the first commercial browser MOSAIC (became later Netscape navigator) was created.
  2. 1994 Berners-Lee who is now a professor at MIT created the W3C that oversees the Web standards and he serves till now as the head of that consortium.
  3. 1996 Microsoft launched its Internet Explorer and its Hotmail webmail service and in 1999 Microsoft and its IE overtook Netscape navigator and blogger publishing service was launched.
  4. 1998 search engine Google started and performed over 3 million searches/day
  5. 2003 more than 3 billion web pages posted on the WEB. And 2004 Mozilla launched the newest browser FIREFOX
  6. 2006 the number of Web pages approached the 10 billions

2-Website- Web page

  1. A website is a collection of web pages it is like a folder of HTML files (public- HTML)
  2. A web page is an HTML file that can be opened by a browser
  3. Items in each page are linked with other items in the same page or in other pages by means of hyperlinks that was behind the hypertext file and hypertext protocol names.
  4. Hyperlink: Element in an electronic document that when clicked, opens a related documentHypertext, hypermedia
  5. Hypertext Transfer Protocol (HTTP): Stateless protocol that works as a mailman to control communication between browsers of Web clients and Web servers

3-Web browser:

  1. It is a utility system software that connect users with different websites and web pages and perform 2 functions:
  2. Use URL and HTTP (Hypertext transfer protocol)to request Web pages ad websites from Web servers that host them.
  3. Display the pages on user’s monitor.
  4. If pages are not available it displays a message about that.
  5. Browser doesn’t possess all necessary tools to tackle all multimedia files without help; it rather needs the services of helper system software programs specialized in dealing with diversity of multimedia files. Helper applications can be a:
  6. Plug-in: Built tohelp the Web browser and enable it to offer extended services that enable users to view animations and videos, and interact with games and other multimedia content
  7. Flash is a popular plug-in
  8. Media player is stand-alone system software that enables the browser to open and play multimedia files (Microsoft media player)
  9. Players and plug-in are known as helper applications that extend the power of the browser in dealing with multimedia files.
  10. Streamingmultimedia enables the browser to begin playing the content of the file while it is being downloaded

4-Web server: completes the following functions:

  1. Stores Web pages of websites they host
  2. Store other related files (hyperlinked files)
  3. Store files related to other Web services
  4. Listen to HTTP that delivers browser requests for web pages.
  5. Retrieve the pages stored on its databases
  6. Delivers requested Web pages to HTTP

5-Web authoring languages

  1. HTML(Hypertext Markup Language) (refer to the XHTML tutorial on the course website-helpful links) HTML is the basic language: HTML5 or XHTML is the latest version
  2. Uses predefined formatting tags
  3. Tags are used in pair between brackets
  4. The example below shows how this language works.

<!DOCTYPE HTML>
<html>
<head>
<title>Title of the document</title>
</head>
<body>
The content of the document......
</body>
</html>

b-XML(Extensible Markup Language):

i-It is a more friendly language based on HTML and allows the designer to use his own tags that are usually more related to the content of the page. This is a web friendly language. See the example below:

<Grocery>
<Grocery type="seafood">
<fish>red snapper</fish>
<origin>wild caught</origin>
place>Alaska</place>
<price>12.99</price>
</Grocery

c-WML(Wireless markup language):

i-WML is designed for web applications that are able to run on mobile devices such as iPad, Android and smart phones.

ii-WML it is based on a special XML tag system thatuses Select tags to define the selection

6-Web authoring software

  1. Many WYSIWYG (What You See Is What You Get) web authoring software help you author web pages by following templates and taking a do it by yourself approach
  2. You don’t have to start from scratch like you do with HTML or XML; instead you follow a wizard or template that is already built using tags.
  3. You can use these application software even if you don’t know any Web authoring language
  4. Important characteristics of WYSIWYG application software are:
  5. Very convenient and very fast in authoring webpages
  6. Templates almost make the web site authoring a very easy automatic task

7-Important WYSIWYG software includes and not limited to:

  1. CoffeeCup Visual Site Designer
  2. Excellent for beginners
  3. Very friendly WYSIWIG interface for Web design
  4. Serif WebPlus X2
  5. Abundance of useful web design features
  6. Abundance of wizards and templates
  7. Very easy to use for beginners and professionals as well.
  8. Web Easy Professional
  9. Visually oriented design interface
  10. Knowledge of mark-up languages is not required
  11. NetObjects Fusion 11
  12. Enable beginners to build interactive websites
  13. Fit all types of interactive well designed websites.
  1. Eversoft First Page
  2. One of the first web design and development tools
  3. It may be used by absolutely non experienced newcomers
  4. Includes HTML editors and many tools that make the process easier and faster to complete.
  5. HTML-Kit Tools
  6. Requires knowledge and experience of mark-up languages
  7. It cannot be used by beginners
  8. It extends very proficient web design tools to experienced designers.
  9. Other Web development software for professional designers include
  10. AceHTML 6 Pro
  11. UltraEdit
  12. TopStyle
  13. BestAddress HTML Editor
  14. Adobe Creative suite CS6 is a heaven for Web and graphics design offered by its powerful software tools for web and graphics design.
  15. Microsoft discontinued its Expression web design software and made it part of visual studios-12
  16. Both Adobe and MS software target professional designers and Web development experts.

8-Web authoring services/web templates

  1. Services that design and complete the website for you
  2. They are expensive and the follow-up is always a problem
  3. On the other hand thousands of templates are available for you on the Web to choose from and you usually have 2 options:
  4. You buy the template entirely so that nobody else can use it and the price in this case will be between 2 and 10 thousand dollars and may be more.
  5. You use the template one time to author your web page and the price will be few hundred dollars or less.

Web addressing:

1-IP address

  1. Four numbers (0 to 255) separated by periods, such as 64.233.161.104
  2. 4 bytes are used to store the IP address
  3. The number in each byte cannot exceed 255
  4. The number of IPs available is 256^4

2-Domain name is an associated English names assigned to IP addresses

3-Uniform Resource Locator (URL)

  1. Acts as a Web page address
  2. As clear address of web pages, URLs make web addresses easy to remember and use
  3. URL incorporates domain name of Web server and location of Web page file on server

4-Top-level domain (TLD):Final portion of domain name of which we will consider:

  1. .com used for commercial sites
  2. .edu used for education sites
  3. .gov used for government sites
  4. .org used for non-profit sites, etc….

5-Web portals:Pages designed to act as entry points to the Web

6-ISP (Internet Service Provider) must maintain a farm of servers including a domain name server that converts URLs into their corresponding IP addresses.