How to Communicate via Internet Press a key to start

a Technical Overview

How to Communicate via Internet How to Communicate via Internet Press a key to startPress a key to start

How to Communicate via Internet How to Communicate via Internet Press a key to startPress a key to start

ProblemProblemProblemProblem

Preface

DATADATA

INFORMATIONINFORMATION

DECISIONDECISION

KNOWLEDGEKNOWLEDGE

„SOMETHING”„SOMETHING”

ACTIONACTION MONITORINGMONITORING

Actual Actual statestate

Ideal Ideal statestate

What is the INFORMATION?What is the INFORMATION?What is the INFORMATION?What is the INFORMATION?

Preface

information must:information must:• be SOMETHING, although the exact be SOMETHING, although the exact

nature nature (substance, energy, or abstract (substance, energy, or abstract concept)concept) isn’t clear isn’t clear;;

• provide NEW informationprovide NEW information: a repetition of : a repetition of previously received message isn’t informative;previously received message isn’t informative;

• be TRUEbe TRUE: a lie or false information is mis-: a lie or false information is mis-information, not information itself;information, not information itself;

• be ABOUT somethingbe ABOUT something..

Cookie Monster: Cookie Monster: „ - News or facts about something.„ - News or facts about something.””

This definition is consistent with the common notions that

What is the COMMUNICATION?What is the COMMUNICATION?What is the COMMUNICATION?What is the COMMUNICATION?

- Cookie Monster: - Cookie Monster: „ Exchanging information.„ Exchanging information.””

( … in time and space … )( … in time and space … )

1. CODING the information 1. CODING the information (at the sender side)(at the sender side)..2. SENDING - RECEIVING codes 2. SENDING - RECEIVING codes (via (via channelchannel))..3. DECODING the information from codes 3. DECODING the information from codes (at the (at the

receiver side)receiver side)..

Communication in General

on-lineon-line // off-lineoff-line

point - pointpoint - point // broadcasted broadcasted


Communication TypesCommunication TypesCommunication TypesCommunication Types

he Internet, sometimes called simply "the Net,” is ahe Internet, sometimes called simply "the Net,” is aworldwide system of computer networks - a network of worldwide system of computer networks - a network of

networks in which users at any one computer can, if they have networks in which users at any one computer can, if they have permission, get information from any other computer (and permission, get information from any other computer (and sometimes talk directly to users at other computers). It was sometimes talk directly to users at other computers). It was conceived by the Advanced Research Projects Agency conceived by the Advanced Research Projects Agency (ARPA) of the U.S. government in 1969 and was first known (ARPA) of the U.S. government in 1969 and was first known as the ARPANet. The original aim was to create a network as the ARPANet. The original aim was to create a network that would allow users of a research computer at one that would allow users of a research computer at one university to be able to "talk to" research computers at other university to be able to "talk to" research computers at other universities. A side benefit of ARPANet's design was that, universities. A side benefit of ARPANet's design was that, because messages could be routed or rerouted in more than because messages could be routed or rerouted in more than one direction, the network could continue to function even if one direction, the network could continue to function even if parts of it were destroyed in the event of a military attack or parts of it were destroyed in the event of a military attack or other disaster. other disaster.


INTERNET - INTERNET - HistoryHistoryINTERNET - INTERNET - HistoryHistory

TT

Today, the Internet is a public, cooperative, and self-Today, the Internet is a public, cooperative, and self-sustaining facility accessible to hundreds of millions of people sustaining facility accessible to hundreds of millions of people worldwide. Physically, the Internet uses a portion of the total worldwide. Physically, the Internet uses a portion of the total resources of the currently existing public telecommunication resources of the currently existing public telecommunication networks. Technically, what distinguishes the Internet is its networks. Technically, what distinguishes the Internet is its use of a set of protocols called TCP/IP (Transmission Control use of a set of protocols called TCP/IP (Transmission Control Protocol/Internet Protocol). Protocol/Internet Protocol).

•Many cases e-mail has practically replaced the Postal Many cases e-mail has practically replaced the Postal Service for written transactions. Electronic mail is a widely Service for written transactions. Electronic mail is a widely used application on the Net. used application on the Net.

•Internet telephony allows real-time voice conversations. Internet telephony allows real-time voice conversations. •The most widely used part of the Internet is the World The most widely used part of the Internet is the World

Wide WebWide Web.. Its outstanding feature is Its outstanding feature is hypertexthypertext..


INTERNET - INTERNET - TodayTodayINTERNET - INTERNET - TodayToday

Internet as the Medium of Human-HumanHuman-Human Communication

E-Mail (Electronic Mail)E-Mail (Electronic Mail)E-Mail (Electronic Mail)E-Mail (Electronic Mail)• E-mail was one of the first uses of the Internet and is still E-mail was one of the first uses of the Internet and is still one of one of the the

most popular use. A large percentage of the total traffic over the most popular use. A large percentage of the total traffic over the Internet is e-mail.Internet is e-mail.

• Off-lineOff-line ( (but the duration of delivery can be less than a minutebut the duration of delivery can be less than a minute))..• Point to pointPoint to point connection, but you can send the same letter to connection, but you can send the same letter to

several addressseveral address (multipoint) (multipoint)..• You can send: You can send:

– plain (plain (ASCIIASCII text) or formatted (HTML) text text) or formatted (HTML) text– binary files (images, sound) as attachmentbinary files (images, sound) as attachment– voice- or videomailvoice- or videomail

• E-mail client programs eg.:E-mail client programs eg.:– ThunderBird, ThunderBird, Outlook ExpressOutlook Express

• Off-lineOff-line (e-mail) (e-mail). Your e-mail client enough to use this . Your e-mail client enough to use this feature. feature.

• If you subscribed, you will automatically get every e-mail If you subscribed, you will automatically get every e-mail has sent to the list.has sent to the list.

• Broadcasted. If you send a message to the address of the list, Broadcasted. If you send a message to the address of the list, everybody who subscribed will get your mail. (You don`t everybody who subscribed will get your mail. (You don`t (have to) know exactly who will get your message).(have to) know exactly who will get your message).


Mailing ListsMailing ListsMailing ListsMailing Lists


On-line ChatOn-line ChatOn-line ChatOn-line Chat• On the Internet, chatting is talking to other people who are On the Internet, chatting is talking to other people who are

using the Internet at the same time you are. using the Internet at the same time you are. (on-line)(on-line)• Usually, this "talking" is the exchange of Usually, this "talking" is the exchange of typed-intyped-in messages messages

(low bandwidh needed). (low bandwidh needed). • It could be broadcasted - It could be broadcasted - group chatgroup chat (everybody has joined (everybody has joined

the chat room can see your message) or point-point - the chat room can see your message) or point-point - private private chatchat (between two person). (between two person).

• A chat can also be conducted using sound, video; assuming A chat can also be conducted using sound, video; assuming you have the bandwidth access.you have the bandwidth access.

• Such services: Such services: – MSN, ICQ, IRC, Chat roomsMSN, ICQ, IRC, Chat rooms


Phone via InternetPhone via InternetPhone via InternetPhone via Internet• Internet telephony is the use of the Internet rather than the Internet telephony is the use of the Internet rather than the

traditional telephone company infrastructure to exchange traditional telephone company infrastructure to exchange spoken or other telephone information. spoken or other telephone information.

• You can callYou can call– Another computer (if your parner have registered to the Another computer (if your parner have registered to the

service, and actually online)service, and actually online)– Telephone (a provider connects the telephone network to Telephone (a provider connects the telephone network to

the internet on the other side, for a fee)the internet on the other side, for a fee)• Programs and services eg.:Programs and services eg.:

• Skype, Skype, • MSN,MSN,• NonohNonoh


Phone via InternetPhone via InternetPhone via InternetPhone via Internet

Sound DigitalizationSound Digitalization (real-time voice transfer needs more bandwidth than typed in chat)(real-time voice transfer needs more bandwidth than typed in chat)


Video Transfer via InternetVideo Transfer via InternetVideo Transfer via InternetVideo Transfer via Internet• Real-time Real-time (on-line) (on-line) video transfer require much wider video transfer require much wider

band than voice transfer. band than voice transfer. • The following types of video transfer occur on the Net:The following types of video transfer occur on the Net:

– On-line, point to point On-line, point to point videoconferencevideoconference– On-line, On-line, broadcastedbroadcasted audiovisual feeds audiovisual feeds (internet (internet

tv channels, youtube)tv channels, youtube). . – Off-line, Off-line, pre-recorded audio/video archives.pre-recorded audio/video archives.

Real-time transfer is Real-time transfer is rarelyrarelydemanded in this case.demanded in this case. YouYoucan download the wholecan download the whole filefile(slowly) and playit from (slowly) and playit from youryourlocal (fast) harddrive.local (fast) harddrive.


Video Transfer via InternetVideo Transfer via Internet - Videoconference - VideoconferenceVideo Transfer via InternetVideo Transfer via Internet - Videoconference - Videoconference• A videoconference is a group or a person-to-person discussion A videoconference is a group or a person-to-person discussion

in which participants are at different locations but can see and in which participants are at different locations but can see and hear each other as though they were together in one place. hear each other as though they were together in one place.

• Most off-the-Internet videoconferences today involve the use of Most off-the-Internet videoconferences today involve the use of a room at each geographic location with special videoa room at each geographic location with special video camera camera and document presentation facilities. In general, traditional and document presentation facilities. In general, traditional videoconferencing requires special telephone interconnections videoconferencing requires special telephone interconnections with wide bandwidth. with wide bandwidth.

• On the Web, On the Web, a lot ofa lot of product product (skype, webinars, (skype, webinars,msn)msn),, offers a simple form of videoconference offers a simple form of videoconference withwith each user (optionally aiming a small each user (optionally aiming a small

videovideo camera at herself or himself) connected to camera at herself or himself) connected to otherother users in a pre-arranged chat session. users in a pre-arranged chat session.


Video Transfer via InternetVideo Transfer via Internet - Streaming Video - Streaming VideoVideo Transfer via InternetVideo Transfer via Internet - Streaming Video - Streaming Video• Streaming video is a sequence of "moving images" that are Streaming video is a sequence of "moving images" that are

sent in sent in compressedcompressed form over the Internet and displayed by form over the Internet and displayed by the viewer as they arrive. Streaming media is streaming the viewer as they arrive. Streaming media is streaming video with sound. video with sound.

• The user needs a The user needs a playerplayer, which is a special program that , which is a special program that uncompressesuncompresses and sends video data to the display. and sends video data to the display.

• Streaming video is usually sent from prerecorded video Streaming video is usually sent from prerecorded video files, but can be distributed as part of a files, but can be distributed as part of a live broadcast live broadcast "feed"feed”.”.

• Eg: YouTube, internet televisionEg: YouTube, internet television

Why Human-Machine communication?Why Human-Machine communication?Why Human-Machine communication?Why Human-Machine communication?• The previous services are to facilitate the The previous services are to facilitate the directdirect human human

communication. The next services are to use the resources communication. The next services are to use the resources of a far computer (run a program on it, access files, etc.)of a far computer (run a program on it, access files, etc.)

• You can download data (text, picture, sound, video...) You can download data (text, picture, sound, video...) stored on an Internet connected computer without other stored on an Internet connected computer without other people direct assistance.people direct assistance.

• You have to say to the server computer what do you want You have to say to the server computer what do you want to get and the server will send it to you automatically.to get and the server will send it to you automatically.

• Previously of course the owner of the server has to allow Previously of course the owner of the server has to allow the accessing.the accessing.

Internet as the Medium of Human-MachineHuman-Machine Communication


A few Technical ConceptsA few Technical ConceptsA few Technical ConceptsA few Technical Concepts

The following technical points haven`t been mentioned at The following technical points haven`t been mentioned at the part of e-mail, the part of e-mail, telephonytelephony, , chatchat, etc. In general you , etc. In general you don`t have to know them to use that services. But now don`t have to know them to use that services. But now these concepts will be more visible for the average user.these concepts will be more visible for the average user.

Client / Server architectureClient / Server architectureTCP/IP protocolTCP/IP protocol

DNSDNSURLURL

Remote accessRemote accessRemote accessRemote access• Remote access Remote access is the way you can access someone else's is the way you can access someone else's

computer, assuming they have given you permission. With computer, assuming they have given you permission. With these client-server programsthese client-server programs, you log on as a regular user , you log on as a regular user with whatever privileges you may have been granted to the with whatever privileges you may have been granted to the specific applications and specific applications and datadata on that computer. on that computer.

• The result of this request would be an invitation to log on The result of this request would be an invitation to log on with a userid and a prompt for a password. If accepted, you with a userid and a prompt for a password. If accepted, you would be logged on like any user who used this computer would be logged on like any user who used this computer every day.every day.

• You can use applications running on the serverYou can use applications running on the server..

• Eg. Telnet, VNC, Remote DesktopEg. Telnet, VNC, Remote Desktop



FTP (File Transfer Protocol)FTP (File Transfer Protocol)FTP (File Transfer Protocol)FTP (File Transfer Protocol)• FTP, a standard Internet FTP, a standard Internet protocolprotocol, is the simplest way to , is the simplest way to

exchange files between computers on the Internet. FTP is exchange files between computers on the Internet. FTP is an application protocol that uses the Internet's an application protocol that uses the Internet's TCP/IPTCP/IP. .

• FTP is commonly used to transfer Web page files from FTP is commonly used to transfer Web page files from their creator to the computer that acts as their their creator to the computer that acts as their serverserver. It's . It's also commonly used to download files to your computer also commonly used to download files to your computer from other servers. Using FTP, you can also update files from other servers. Using FTP, you can also update files at a server. at a server.

• You need to log on to an FTP server. However, publicly You need to log on to an FTP server. However, publicly available files are easily accessed using anonymous FTP. available files are easily accessed using anonymous FTP.

• Commonly used FTP client programs eg.:Commonly used FTP client programs eg.:– CuteFTP, WsFTP, CuteFTP, WsFTP,

What Is It?

Internet as the Embodiment of Human KnowledgeHuman Knowledge

World Wide WebWorld Wide WebWorld Wide WebWorld Wide Web

• A technical definition of the World Wide Web is: all the A technical definition of the World Wide Web is: all the resources and users on the Internet that are using the resources and users on the Internet that are using the Hypertext Transfer Protocol (Hypertext Transfer Protocol (HTTPHTTP). ).

• A broader definition comes from the organization that A broader definition comes from the organization that Web inventor Tim Berners-Lee helped found, the World Web inventor Tim Berners-Lee helped found, the World Wide Web Consortium:Wide Web Consortium:

"The World Wide Web is the universe"The World Wide Web is the universeof network-accessible information,of network-accessible information,

an embodiment of human knowledge."an embodiment of human knowledge."

World Wide WebWorld Wide Web - Getting Started - Getting StartedWorld Wide WebWorld Wide Web - Getting Started - Getting Started• Using the Web, you have access to millions of pages of Using the Web, you have access to millions of pages of

information. Web "surfing" is done with a Web browser, the information. Web "surfing" is done with a Web browser, the most popular of which are most popular of which are FirefoxFirefox and Microsoft Internet and Microsoft Internet Explorer. Explorer.

• A browser is an application program that provides a way to A browser is an application program that provides a way to look at and interact with all the information on the World Wide look at and interact with all the information on the World Wide Web. Web.

• Technically, a Web browser is a client program that uses the Technically, a Web browser is a client program that uses the HTTPHTTP (Hypertext Transfer Protocol)(Hypertext Transfer Protocol) to make requests of Web servers to make requests of Web servers throughout the Internet on behalf of the user.throughout the Internet on behalf of the user.

• HTMLHTML (Hypertext Markup Language)(Hypertext Markup Language) is the set of "markup" symbols is the set of "markup" symbols or codes. Thor codes. This language is used to define the content ans is language is used to define the content ans structure of the web pages, understanded by structure of the web pages, understanded by the browserthe browserss..

Internet as the Embodiment of Human KnowledgeHuman Knowledge

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