Tom Rebold, MPC

FLUENCY WITH INFORMATION TECNOLOGY

Skills, Concepts, and Capabilities

Tom Rebold, MPC

Becoming Skilled At Information Technology

PART 1

Tom Rebold, MPC

MAKING THE CONNECTION

The Basics of Networking

chapter3

How networking has changed society Types of communication technology Internet addresses and DNS servers Internet protocols LANs vs ISPs Internet vs WWW File heirarchy

4

Social impact of the internet

• Nowhere is remote – Alaska and New York: equal access to info

• People are more interconnected – Instant messaging or e-mail

• Social relationships are changing – Decline in social interactions

• English is becoming a universal language • More freedom of speech & assembly

– Chat rooms, newsgroups, websites

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Types of communication

• Synchronous—both ends active at the same time (telephones)

• Asynchronous—postcards, answering machine, e-mail

• Broadcast—radio, TV• Multicast—magazines • Point-to-point—telephone • The internet supports all these types (in

modified forms)

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Internet possibilities

• Synchronous—instant messaging, IP phone

• Asynchronous—e-mail

• Broadcast—web site

• Multicast—group e-mail, newsgroup

• Point-to-point—e-mail

Copyright © 2003 Pearson Education, Inc. Slide 1-7

A diagram of the Internet

The network is a medium just like TV or radio

Routers

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Computers connected to the Internet are given IP addresses

IP=Internet Protocol

Domain names are easier to remember

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A domain hierarchy

A domain is a related group of networked computers

This diagram locates: spiff.cs.washington.edutracer.cs.washington.edu

And what else?

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Another View of Domains

Top level domains(all in US)

Also many other countries: .uk .ca .de ...

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Hosts like Spiff make requests to a local DNS server...(for www.mpc.edu)

DNS: domain name systemServer: a computer that serves information

DNS servers look up the IP address of

domain name (132.129.0.57)

Sometimes more than one DNS

server is queried

Request goes to the right IP address

Copyright © 2003 Pearson Education, Inc. Slide 1-12

The TCP/IP postcard analogy.(Transmission Control Protocol/Internet Protocol)

Messages are broken into small units and sent one at a time to their destination

Like sending a novel to your publisher one postcard at a time!

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The Internet makes use of whatever routes are available to deliver packets.

Packets go in many directions

They may even arrive out of order

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A ping from the author’s machine to eth.ch (Switzerland) makes 19 hops

The Internet is a “wide area network” (WAN)

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Robert Metalfe’s original drawing of the Ethernet design; the unlabeled boxes, computers, “tap” onto the wire that Metcalfe has labeled “The Ether.”

Computers in our laboratory are on a “local area network” (LAN) using Ethernet

Computers listen before talking like people at a party

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Connecting to the internet

• You can use an Internet Service Provider (ISP) reached by modem, DSL or cable-modem

• Or use a LAN in a larger organization (intranet) with access to the internet

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Internet vs the World Wide Web (WWW)

• Web server:

– a computer (on the internet) that sends web pages to other computers

– Web servers and web pages together make up the world wide web (WWW)

• To request a web page, you provide the URL

– (Uniform Resource Locator) like www.mpc.edu– Page is sent using hypertext transfer protocol (

http://www.mpc.edu) ( http:// optional )

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Dissecting a URL

www.mpcfaculty.net/tom_rebold/students2/David.html

Server name Path name to web page—Tells which folders its inAnd the file name

The actual page file nameDavid.html

folder folder

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A Web page

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The HTML source that produced the previous web page. Notice that an additional image file, alto.jpg, is also required to display the page.

HTML1. Takes less space 2. Lets browser adjust image

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A hierarchy diagram showing the path between xerox-alto.jpg and the desktop.

Down=deeper into tree, toward the leaves

Up=higher, toward the root

Directory hierarchy

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Locating the web page www.nasm.si.edu/galleries/gal100/pioneer.html on the server www.nasm.si.edu

gal100

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Chap 3 review questions 2. English is becoming the universal language as a result of all

of the following except:A. American pop cultureB. the dominance of science and technology in English-speaking

countriesC. information technology’s predominant use of EnglishD. the Alto Project

3. Overall, the ability of individuals to create and publish Web pages:

A. presents an enormous security riskB. extends human expressionC. has led to a proliferation of hate pages and pornographic sitesD. has unduly diverted huge sums from other IT projects

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Chap 3 review questions

5. If the Internet consisted of four computers, there would be six possible connections. If it consisted of five computers, there would be ten possible connections. How many connections are possible with ten computers?

A. 10B. 30C. 45D. Infinite

1. eCommerce is the shortened term for _____.3. A communication that goes out to many people

within a specific target audience is called a ______.