A Brief History of the Internet
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A Brief History of the Internet
What exactly is the Internet?
Who owns it?
(hint . . . not him)
How is it used?
How many people have it?
How many pages are there??
How it works
What is a Network?
Computer
Example of a Network
NetworkPrinter
ComputerComputer Computer
Computer
NetworkServer
Share data, software, and hardware
Network – two or more connected computers
Connected with cables . . .
Telephones . . .
Or satellite (or some other communication medium).
Basic Networks: LAN vs. WAN
• LAN – Local Area Network (computers which are connected and in the same physical area)– Ex: AHS is a LAN
• WAN – Wide area Network, computers are spread over a wide area– Ex: FBISD uses a WAN
So the Internet is a network?
• Any two networks joined together are called an internetwork or internet
• The global network which serves 105 million users worldwide is the Internet
The Internet
• Worldwide group of connected networks that allows public access to information and services
• Some networks are local, some are regional, and some are national
Who owns the Internet?
• No single organization owns or controls the Internet (Advantages? Disadvantages?)
When was the Internet Invented?
And was Al Gore really there?
The Internet
• Began in late 1960s
• Networks at several universities joined to form the ARPANET (UCLA, Stanford, UC Santa Barbara, and the University of Utah)
• Funded by the Department of Defense
J.C.R. Licklider
Founding director of ARPA's Information Processing Techniques Office (IPTO)
His vision: an “Intergalactic network”
The birth of the Internet depended on several
innovations. . .
Leonard Kleinrock MIT
Packet Switching
• Takes data and divides it into packets (e-mail, file, document, or a request)
• Sends packets to destination computer
• Destination computer reassembles message
Bob Kahn and Vint Cerf
TCP/IP
TCP/IP
• Bob Kahn and Vint Cerf developed TCP (Transmission Control Protocol) in 1974
• TCP was an improvement over NCP (Network Control Protocol) which only allowed communication between computers on the same network.
• This new protocol allowed diverse computer networks to interconnect and communicate with each other
Non-Centralized Networks
Nodes can function separately or as a group
Non-centralized networks
Networks which have independent nodes
Non-centralized networks
Nodes can continue to
function even if part of the network
is damaged or destroyed
Non-centralized networks
The Internet: Original Goals: National Security
• Develop a geographically dispersed network which could function even if part was disabled or destroyed
• Create a way scientists from different locations could share information and collaborate on military and scientific projects (particularly space travel)
So if the Internet’s been around since the late
1960’s . . . How come my parents never heard of it until
1993?
Until the 1990s, the Internet was primarily used by
scientists and computer nerds.
There wasn’t much there to appeal to “normal” people . . .
Until . . . .
The First Browser
• Marc Andreesen (an undergraduate student at the University of Illinois) led a team that developed first graphic interface browser called Mosaic in 1993.
• Made it much easier for users to navigate the Internet
The First Browser
• Replaced a text-only interface with one that supported graphics and evolved to support:
•Sound
•Multimedia
•Animation
•VideoBTW: Mosiac still exists – it’s now called Netscape.
Now, everyone’s
“surfin’ the ‘net” . . .
Internet Statistics May 2004
• ~950 million users
• 275 connected countries
• Average user spends more than 17 hours per month online
The World Wide Web
• Collection of hyperlinked documents
• Web site - Internet location containing hyperlinked documents
• Web page - a hypertext document residing on an internet computer
Addressing the Internet
How to get around
Web Addresses
• A web address is called a URL (Uniform Resource Locator)
• Address will be either – an IP address
(ex: 123.1.45.112
– or a domain name (ex: www.nike.com)
Anatomy of a Web Address
Internet Addresses
• Domain names must be registered in the domain name system (DNS)
• Domain names are stored in domain name servers which look up the address
• Advantages to using a domain name?
Internet Addresses:
• International Web Sites
• Includes a country code – .uk United Kingdom – .ca Canada – .ie Ireland
Internet Addresses:
• Domestic Web Sites– .com Business – .edu Colleges and Universities – .gov U.S. Government – .int International Treaty Organizations – .mil Military – .net Network and Administrative – .org Miscellaneous Organizations
The Internet
Getting Connected
The Internet & How to Connect
• Internet Service Provider
• Online services (AOL, Everyone’s Internet, Roadrunner, SBC)
Methods of Connecting: Dial-up Modem
• Uses existing phone lines
• Speed maxes out at 56 KBPS (kilobits per second)
• Average speed runs at 33.6 KBPS
• Compression software (like WebJet) can speed up download speed a bit . . .
Methods of Connecting: Dial-up Modem
Requires: Phone lineModemWeb browser
Methods of Connecting: Dial-Up
Pros: • Least expensive• Uses existing phone
lines (so you can connect from anywhere)
Cons: • Slower access
speed• Delay to establish a
connection• Occasional
disconnections• Can interfere with
phone use
Methods of Connecting: Broadband
• General term for using existing wires (phone, satellite, cable) for your Internet connection
• Connections are “always on”
• Much greater connection speeds
Methods of Connecting: Cable Modem
• Uses same connection as cable TV
• Speed varies from 2 Mbps to 5 Mbps (megabits per second)
• Must live in an area with optical fiber cable
• Access is generally $30 - $50 per month (can be bundled with other cable services)
Methods of Connecting: Cable Modem
Requires: Cable connectionCable modemEthernet connectionWeb Browser
Alternate Methods of Connecting: Cable Modem
Pros: • Higher speeds• Always available• Doesn’t interfere
with phone use • Reliability of service
Cons: • When several
people in the same neighborhood are sharing the same line, access speeds can go down
• Must live in a cable-ready area
Alternate Methods of Connecting:
Digital Subscriber Line (DSL)
• Available from phone company
• Speeds up to 1.5 Mbps
• Access costs $30-$50 per month (can be bundled with other phone services)
Methods of Connecting: DSL
Requires: DSL connectionFilters to separate data signal from voice
signalDSL modemEthernet connectionWeb Browser
Alternate Methods of Connecting: DSL
Pros: • Faster speeds• Always available• More reliable
connection
Cons: • Speed and reliability
of connection depends on your distance from provider
The Internet
Other applications
E-mail: In the beginning
• E-mail was adapted for the Internet by an Engineer named Ray Tomlinson in late 1971.
• He used the format username@domain, because – The @ symbol was rarely used.– He liked the implication that the user was “at”
a different location.
E-mail: Keep in Mind
• Must have an ISP
• Mailbox is stored on the server of the ISP
• When you connect, messages are downloaded to your computer
Benefits of E-Mail
• Faster than traditional mail
• Can send electronic documents, pictures, video
• Easier to send to large groups
• Keeps a record of message for sender
• Saves paper (in theory)
Drawbacks of E-Mail
• Spam
• Less formal
• Some folks don’t check e-mail regularly
• Systems go down
• Messages "lost in cyberspace"
• Changes people’s expectations of response time
Tips for Electronic Communication
• Never send chain letters through the Internet!
• Be professional and careful what you say about others. E-mail is easily forwarded
• Be careful when using sarcasm and humor.
• You may use emoticons and Acronyms. • Remember how easy to is to forward
messages – be careful what you say!
Tips for Electronic Communication
• Never assume your e-mail is private. Never send something you would mind seeing on the evening news.
• Keep paragraphs and messages short and to the point
• Capitalize words only to highlight an important point or to distinguish a title or heading. Don’t SHOUT!
Newsgroups
• A newsgroup is a collection of news and discussion groups
• A newsgroup operates as if it were a bulletin board devoted to a particular subject
• Older newsgroups require a newsreader to read messages (most new browsers have built-in newsreaders and many new bulletin boards use web technology)
Newsgroups
• Some newsgroups are supervised by a moderator who reads each posting before it is posted to the newsgroup
• FAQs prevent new newsgroup users, called newbies, and others from asking the same questions over and over
• Some newsgroups allow anyone to post, while some require users to register and obtain a password
LISTSERV
• Subscribe via e-mail
• Periodically, messages on a given topic will be e-mailed to your mailbox
• Check your e-mail often!!
Newsgroups vs. Listserv
• Newsgroups allow you to choose what messages you want to read, Listserv e-mails all messages to you
• Can browse or “lurk” at a newsgroup, but you must provide an e-mail address to be part of a listserv
Browsers sometimes have trouble accessing newsgroups, but e-mail is e-mail . . .
Chat Rooms/Instant Messaging
• Becoming one of the most popular Internet applications
• Allows users to communicate in real-time• Can participate in a general discussion or
have a private discussion with one or more people
• Some people maintain “buddy lists” and can be alerted when their friends are on-line
Chat Rooms
• Because of the speedy typing required, many people most participants use lots of abbreviations, acronyms, and emoticons
Emoticons (some examples)
• :-) happy • ;-) winking • 8-) glasses or
really paying attention
• >:-( angry (or goat-man)
• (:-) bald • :-o surprised • :-x sour
• :-p sticking tongue out
• {:-) eyebrows or hair parted in middle
• (:-( sad bald man • (:-* kisses • (:-1 ambivalent • (:-c ?
Acronyms/Abbreviations
• BFN - bye for now
• BTW - by the way
• IMHO - in my humble opinion
• LOL - laughing out loud
• ROTFL – rolling on the floor laughing
• TTFN - ta ta for now
• TYVM - Thank you very much
Acronyms/Abbreviations
• BRB – Be right back
• GMTA – Great minds think alike
• AFK – Away from keyboard
• HTH - hope this helps
• TIA – thanks in advance
• GTG – got to go
Tips for Chat Room Conversations
• Realize that no one may be who they say they are
• Never ever ever give personal information to people in a chat room
• Never agree to meet (in real life) anyone you “meet” in a chat room
• If you receive any inappropriate communication, notify the moderator of the chat room and your parents (or other adult)!!
Blogs
• Short for “web logs”
• Online journals or diaries
• Lots of people from celebrities to political activists post blogs . . .
Podcasts
• Online “broadcasts” available via subscription or by download
• So named in honor of the king of mp3 players . . . The iPod
• Available on a variety of topics
File Transfer Protocol (FTP)
• Allows the exchange of files between computers on the Internet
• Files can be text, graphic, sound, video, or program files
• Some sites limit file transfers to those with permission
• Some sites allow "anonymous FTP" • Must download the file before it can be viewed • Files are generally compressed
Advantages of FTP
• Provides access to files, sound, video, and programs
• Easy to use
• Can use Archie to search a wide range of sites
Disadvantages of FTP
• Material may be pirated or copyrighted
• Can pick up computer viruses
• Might need a decompression program
• Difficult to tell if information is useful until it is already on your system
Intranets
• Internal networks which use internet and web technology
• Basic uses: directories, calendars, benefit information
• Advanced uses: project management, group scheduling, employee conferencing
Intranet Concerns
• Security
• Access
• The more users, the more concerns
Security and the Internet
Security
• Any time you open your computer up to the Internet, you open it up to the possibility of an intrusion
• In other words, the world you want to access may be interested in accessing you back . . .
Firewall
• General term for hardware or software used to restrict access to data on a network
• Used to restrict access to resources and data
Proxy Server
• Computer used to separate two networks (generally yours from the Internet)
• Monitors and controls access to resources (so it can act as a firewall)
• Can be used to Cache or store a copy of a page in local storage
Do I need a personal firewall??
• Do you have broadband (cable, DSL) access?
• Do you use Windows and Outlook?• Do you routinely access files remotely via the
Internet?• Do you operate a web server?• Systems are never 100% hack-proof, but you
should at least make it tough on them
How to protect yourself:
• Use virus protection software
• Keep Windows, your browser and email software up to date
• Have your ISP scan your email for viruses and junk mail (spam).
• Back up your data files on a regular basis
• Keep all passwords secure
How to protect yourself:
• Never send your passwords via e-mail to anyone (even if they claim to be your ISP – your ISP knows your passwords, they don’t need to ask you).
• When you are not accessing the Internet, disconnect the network cable from your computer.
How to protect yourself:
If you just take some simple precautions, you can help protect your system. Even a minimal delay may be enough to persuade hackers to move on to the next victim.
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