Introduction Lecture 1 CNET204 – Web Design with FrontPage Winter 2009 Centennial College

Lecture 1 Outline  What is the Internet?  Where did it come from?  What are we going to discuss in CNET204?  Internet  Physical Infrastructure

The Ever-changing Internet Different colors based on IP address

What is the Internet?  WWW  Video conferencing  ftp  telnet   Instant messaging  … A communication infrastructure Usefulness is in exchanging information

“On-line interactive communities... will be communities not of common location, but of common interest.... the total number of users...will be large enough to support extensive general purpose [computers]. All of these will be interconnected by telecommunications channels... [to] constitute a labile network of networks--ever changing in both content and configuration.” J. C. R. Licklider

Where Did It Come From?  It was invented by Madonna. JUST KIDDING!   Early 1960’s - DARPA (ARPA in 1960’s) project headed by Licklider   Late 1960’s - ARPANET & research on packet switching by Roberts First node installed by BBN at UCLA in September Four host computers (UCLA, SRI, UCSB, University of Utah) Get more info at:

ARPANET,

History of the Internet   RFCs begun by S. Crocker (   by Ray Tomlinson & Larry Roberts   1970’s - TCP by Vint Cerf & Bob Kahn Evolved into TCP/IP, and UDP  1980s – Hardware Explosion (LANs, PCs, and workstations) 1983 – Ethernet by Metcalfe 1983 – Ethernet by Metcalfe  DNS – Distributed and scalable mechanism for resolving host names into IP addresses  UC Berkeley implements TCP/IP into Unix BSD  1985 – Internet used by researchers and developers

History of the Internet  Tim Berners-Lee at CERN in 1989 Proposal for WWW in 1990 Proposal for WWW in 1990 First web page on November 13, 1990 First web page on November 13, 1990   Hypertext - Text that contains links to other text. Ted Nelson’s Xanadu Vannevar Bush’s Memex (   W3C Get more info at:

What will CNET204 cover?  Simple to sophisticated web page creation  Use of Adobe CS4 Dreamweaver HTML and CSS editor Dreamweaver HTML and CSS editor PhotoShop for images, pictures and layering PhotoShop for images, pictures and layering Flash for animations Flash for animations  Tables  Layout Tables  Cascading Style Sheets (CSS)  Web Project done individually

Course Details  Grading 30% 4 assignments 30% 4 assignments 30% Midterm 30% Midterm 40% Final Project 40% Final Project All work must be posted to studentweb by the due date All work must be posted to studentweb by the due date

Lab Assignments  Assignment #1 Home Page Home Page  Assignment #2 Page with Image maps Page with Image maps  Assignment #3 Tables Tables Layout Tables Layout Tables  Assignment #4 Forms Forms CSS CSS

Administrative Details  Contacting staff  Communicate through mycentennial  Grading/testing online  Students Rights and Responsibilties

Communicating Via the Internet “Internet has made the information of the world as available as information on a LAN” tracert ipconfig.exe

 Latency – ping command How long minimum communication takes in seconds (s) How long minimum communication takes in seconds (s) Round trip vs. single trip Round trip vs. single trip More difficult to overcome than bandwidth More difficult to overcome than bandwidth  Bandwidth Number of bits per time unit usually seconds (bps) Number of bits per time unit usually seconds (bps) Performance: Latency and Bandwidth bandwidth latency link

Ethernet   Bob Metcalfe at Xerox PARC  Used for local area networks (LANs) Physically near one another Physically near one another 200 computers within 100 meters 200 computers within 100 meters  Broadcast medium Single wire connects all computers Single wire connects all computers Each computer has unique 48-bit MAC addressEach computer has unique 48-bit MAC address All computers constantly listen All computers constantly listen  “Carrier Sense, Multiple Access with Collision Detect” Sender waits until wire unused before sending Sender waits until wire unused before sending If hears collision, stops, waits random time, retransmits If hears collision, stops, waits random time, retransmits