webmaster ii webmaster review - fort collins, co copyright © xtr systems, llc review of webmaster i...
TRANSCRIPT
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Reviewof
Webmaster I
Instructor: Joseph DiVerdi, Ph.D., MBA
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Website Purposes
• Individuals, Organizations, Businesses• Rely on Web Pages
– Provide and Collect Information– Manage Processes– Interact With Communities and Customers
• Reliable, Informative, & Responsive Web Site– Creates a Positive Image– Increases Visibility– Manages Cost
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Webmaster Mission
• Webmasters Make Sure That:– The Information on a Site Is Accessible – The Information on a Site Is Usable– The Site Is Always Available– The Performance Is Good– Users Can Get Needed Information– The Site Can Collect the Information It Needs
• Whatever It Takes to Accomplish These Goals– Legally, Ethically, & Morally
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Potential Webmasters
• Content Providers • Work on the Data Itself, Creating or Editing HTML Documents,
Incorporating Images & Forms, & Maintaining the Integrity of the Links
• Designers• Create the Images & Also Define the “Look” of the Site
• Programmers• Write CGI, Perl, Java, JavaScript, & Other Programs for
Incorporation Into the Site
• Administrators• Make Sure That the Server Runs Properly & Efficiently at All
Times, They Might Also Be for Writing New Scripts & Maintaining Document and Site Security
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Evolution of Webmaster
• “Webmaster” Is Now Too Big for One Person• It Is Supplemented by Other Titles
– Internet Strategist • Develops, Executes, & Manages Strategy for Use of
Internet Technologies in Support of Corporate Initiatives
– Electronic Commerce Manager • Develops, Drives, Executes, & Manages Internet
Commerce for a Business Unit
– Internet Strategy Director • Develops & Implements a Wide Range of Internet
Strategies to Meet Company Business Objectives
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Webmaster vs. Developer
• Webmasters' Responsibilities Are Broader Than Web Developers'– Webmasters Are Expected to Understand the Web
to a Greater Technical Degree Than Are Web Developers
– Web Developers Often Are Expected to Understand Content to a Greater Degree
• Webmasters Often Perform Web Development• Webmasters Often Are "Jacks of All Trades"
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
How the Internet Works
• The Internet Is a Communications Medium Through Which Information Is Transferred Between Computers– Many Different Services Use the Internet for
Transferring Information
• They Most Often Use TCP/IP to Transfer Data– Transmission Control Protocol/internet Protocol
• The Telephone Network Is Also a Communications Medium but With Very Different Characteristics
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
How the Internet Works
• The Internet Is a Packet Switched Network– When Data Leaves the Source Computer It Is
Broken up Into Packets• Small Chunks of Data
– Transmitted Through Larger and Larger Networks• Usually 1-1,500 Bytes Long
• Packets Are Routed Through Many Networks• When the Packets Arrive at the Destination
Computer – They Are Reassembled Into the Original Message
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
How the Internet Works
• Breaking the Data up Into Small Packets– Increases the Efficiency of the Whole Network– Exact Path Taken From the Same Source to the
Same Destination Is Often Different
• Path Depends on the Instantaneous Load– On Each of the Routers & Networks
• Packet Data Is Identified by the Internet Addresses– Of the Source & Destination Computers
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Network Analogies
• US Postal Service Is a Packet Switched Network– No User Receives a Dedicated Piece of the Network
• Routers Are Equivalent to Postal Substations– Mail Sent From Milford, CT to Loveland, CO Does Not
Use a Reserved Plane or Truck• It Is Pooled at a Substation & Sent to a Series of Substations
• Efficient Utilization of Network Resources
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Network Analogies
• Telephone Network Is a Circuit Switched Network– When a Telephone Call Is Made a Piece of the
Network Is Dedicated to That Call
• Even If That Piece Isn't Being Used– Being on Hold– That Piece of the Network Is Unavailable for Use by
Others
• Inefficient Utilization of Network Resources
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Internet Addresses
• An IP Address Uniquely Identifies a Computer• IP Addresses Follow Dotted Decimal Notation
– Four Decimal Numbers – Each Ranging From 0 to 255– Each Number Separated by a Period– The Following Are Unique IP Addresses and
Corresponding to Unique Computers:• 206.168.235.2• 192.122.36.5• 128.174.5.6
• IP Addresses Are Registered & Allocated
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Domain Name System
• A Host Name Is Assigned to Each Computer Only for the Convenience of Human Users– Computers Refer to Each Other by IP Addresses
• Host Names Use a Hierarchical Domain Structure– Right-to-left <–> Most-to-least Significant– Each Domain Is Separated by a Period
• Host Names Are Registered & Allocated– By a Central Authority
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Domain Name Lookup
• Convert a Domain Name Into an IP Address• Use DNS Servers
– Computers Whose Sole Purpose Is to Maintain Lists of IP Addresses and Domain Names
• Local DNS Servers Know Local Addresses– DNS Servers Cache Recently Requested Addresses
• Local DNS Servers Also Know Addresses of More-Significant Domain Name Servers
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Host & Domain Names
• The Following Are Unique Host Names Corresponding to Unique Computers:– woody.xtrsystems.com– lamar.colostate.edu– holly.colostate.edu– nic.ddn.mil– whitehouse.gov– uxc.cso.uiuc.edu– linus.ulltra.com
• One Computer May Have Several Host Names
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Original High-level Domains
Domain Usage
com Commercial Organizations
edu Educational Organizations
gov Non-Military Government Organizations
mil Military Organizations
org Other Organizations
net Network Resources
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Country Domains
• The Internet Is a World-Wide Network• Foreign (Relative to the USA) Countries Have
Responsibility for Their Own Names• Country Codes Are a Set of Two Letter
Highest-level Country Domains• About 300 Country Codes Exist
BO - Bolivia BR - Brazil IR - Iran
CA - Canada TD - Chad IQ - Iraq
FR - France DE - Germany UK - UK
US - USA TO - Tonga TW - Taiwan
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Country Domains
• THe Following Are Unique Host Names Corresponding to Unique Computers:– hockey.guelph.ca– alpha.psd.k12.co.us– ci.fort-collins.co.us– uxc.urbana.il.us
• Host Names Are Registered & Allocated– By Central Authorities
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Telephone Services
• Voice Transmission• Fax Transmission
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Internet Services
• World Wide Web - Hypertext Documents– Other Services Which Use the Internet As a
Communications Medium - Nothing to Do With the WWW
• Telnet - Login to Remote Computers• FTP - Inter-computer File Transfer• Email - Jokes for Everyone• Newsgroups - Bulletin Boards• Internet Relay Chat (IRC) - Chat Rooms
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
How the WWW Works
• The World Wide Web Is an Information Service That Uses the Internet As Its Communication Medium– It Is Based on the Technology Called Hypertext
• Hypertext Is a Method of Presenting Information• Selected Words in a Text Can Be "Expanded"
– To Provide Other Information About the Word– These Words Are Called Links to Other Documents
• Text, Images, Sounds, etc.
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Clients and Servers
• The Web Browser on Your Desktop Is a Web Client– Navigator, Explorer, Opera, Mosaic, Etc.
• Most Common Interface to the WWW• To Request a Document With a Browser It
Needs a Universal Resource Locator (URL)• URL Identifies Computer With Information • URL Identifies Path to the Document
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Uniform Resource Locators
http://perl.oreilly.com/news/2000_june.html
scheme://host/path
Scheme: the Protocol That Connects to the Site
Host: the Name of the Server to Connect
Path: the Location in the Server’s Directory Tree
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Clients & Servers
• Browser Contacts Server (Remote Computer)• Requests Specified Document Using URL• Receives Specified Document• Renders or Displays Document on Browser
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Clients and Servers
• A Server Is a Computer Running Server Software– Apache
• A Server – Sits Patiently Running Server Software– Listening to Its Internet Connection– Awaiting Requests
• Uses Hyper Text Transfer Protocol (HTTP)
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Clients and Servers
• Upon Receiving a Request– Accepts URL Path– Converts Path Into File Name– Returns Status to Requesting IP Address– Returns File to Requesting IP Address, If Found
• Uses Hyper Text Transfer Protocol (HTTP)
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
A Very Simple Transaction
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Simple Transaction w/ Image
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Site Hosting Issues
• Basically Three Options– Your Own Server– Internet Service Provider (ISP)– Presence Provider (PP)
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Site Hosting Issues
• Internet Service Provider (ISP)– A Service From a Company That Houses Its Own
Server Computers Which Rents Out Bits of Them on a Monthly Fee Basis
– ISP Supplies Internet Connection & Sys Admin– Sys Admin Maintains Hardware
• You Call & Complain
– You Access Through Your Own Internet Connection
• Which You Must Purchase Through an ISP
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Site Hosting Issues
• Presence Provider (PP)– A Service From a Company That Houses Its Own
Server Computers Which Rents Out Bits of Them on a Monthly Fee Basis
– ISP Supplies Internet Connection & Sys Admin– Sys Admin Maintains Hardware
• You Call & Complain
– You Access Through Your Own Internet Connection
• Which You Must Purchase Through an ISP
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Site Hosting Issues
• Your Own Server– When You’re Really Big
• Or Tired of Using an ISP
– You Must Supply a Dedicated Internet Connection• DSL, T1, T3, etc.
– You Must Supply One or More Dedicated Computers
– You Must Supply Real System Administrator(s)– You Access Directly
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Site Hosting Issues
• In This Class You Will Use “Local Hosting”– Viewing Web Pages Using a Web Client on the
Same Computer Without Any Server
• You Will Also Use "Remote Hosting"– You Will Be Assigned a Linux Account– On a Server Here at Ulltra Technology Corp.– You Can & Will Access Your Account From Any
Computer With an Internet Connection– You Can & Will Develop Your Web Site From Any
Computer With an Internet Connection
Webmaster IIWebmaster Review - Fort Collins, CO
Copyright © XTR Systems, LLC
Sample Site Configurations
• Low Volume– 1,000 - 10,000 Hits Per Day– 0.01 - 0.1 Hits Per Second - Average– 0.1 - 1.0 Hits Per Second - Peak– Can Be Run Out of The Home (Office)– Good Intel (486, Pentium I) Hardware ($200)
• Or AMD Equivalent (K6, Athlon, etc.)
– Linux Operating System ($0)– Apache Server Software($0)– DSL (0.7 Mbps) (<$100/month)– Flat-file, Perl-hash, or MySQL As Database