1. Client-Server Architecture Browser-WebServer Details
Internet & WWW Details
Client-Server Architecture
Browser-WebServer Details

2. Part 0: Your Project
Your project is to create a working e-commerce website.
Here are some feasible project ideas…

3. Part 1: Internet History & Details
Timeline:
Innovation Phase:
Institutional Phase:
E-commerce Phase: 1995-today

4. Internet Characteristics
Analogy: Human Characteristics that really matter:
Humans walks on two legs
Humans have a 3lbs brain.
Humans communicate with speech and written words

5. Internet Characteristics
Internet characteristics that really matter:
Internet uses packet switching –
data is broken into little packets that have to re-assembled
Internet uses TCP/IP protocol –
robust protocol for sending everything from to video
Internet used IP addresses

6. Innovation Phase: 1961-1974 All the technology was invented
Paul Baran proposed the idea of packet switching for network communication (1962)
Vinton Cerf Proposed TCP/IP Protocol in 1974

7. Institutional Phase: 1980-1993
ARPANet: A purely military network got turned over to Scientists working on Defense Department Projects
National Labs – National Science Foundation
NASA
Department of Energy
Leading Universities
Over in Europe another large network emerged.
CERN – Leading particle physics lab (Geneva, Switzerland)

8. Institutional Phase: 1980-1993
ARPANet and CERN’s network officially became 100% TCP/IP in 1982
Standardization – commitment to this standard protocol allowed software developers to coordinate networking efforts.
In many ways, this marks the birth of the Internet we now know.

9. Side Topic
Didn’t Al Gore invent the Internet?

10. Side Topic Didn’t Al Gore invent the Internet?
Al Gore never made this claim…it’s a complete misquote
Gore’s High Performance Computing and Communication Act of 1991 (Gore Bill) passed in 1991 and led to the National Information Infrastructure.
This directly led to the commercialization of the Internet.
The term Internet started to become widely used.
Gore may have been the first to use the term “information superhighway.”

11. E-commerce Phase: 1995-today
Prior to 1995, the Internet facilitated B2B e-commerce (which is really e-business).
But the systems developed were very specialized and isolated.
True E-commerce wasn’t realized until the end consumer got Internet access.
In 1995, we saw the explosion of Internet Service Providers (ISPs)
AOL
Dialup Providers

12. ISPs of Today
Telephone companies own most of the infrastructure. They are the global players
They farm it out to local ISPs
Cable TV providers are now the biggest local players.
Dialup Still exists
AOL
Netzero

13. Part 1: Internet History & Details
Network of networks built on standardized technology and protocols.
Until the Internet emerged…different groups were using all different kinds of protocols.
Key Term: Protocol
a set of rules governing the format of messages that are exchanged between computers

14. Packet Switching
PAD – Packet assembler/dissembler

15. Why is Packet Switching important?
Otherwise you need a direct, uninterupted connection, which is not feasible.
Network goes down all the time.
Traffic gets re-routed on the fly
Also, its higher performance.
Your packets could take numerous paths in parallel.

16. TCP/IP
Transmission control protocol
Internet Protocol

17. Why is TCP/IP so important
The Internet would never have expanded so rapidly without a commitment to Global Standardization
Its hard to get experts to agree on a single Protocol
TCP/IP is very robust and allows for numerous levels of sub-networks.

18. IP Address
32-bit number
Uniquely identifies devices on the Internet
4 billion unique devices.
There are already more than 4 billion devices:
Sub-netting –
one IP address gets you to a subnet
Subnet uses its own internal IP address.

19. Sub-Networks IP Addresses are a commodity, limited supply.
Controlled by ICANN, which indirectly came from the Gore Bill.
Siena gets Internet Access from Time Warner Cable…we probably pay for IP Addresses, which are reserved for key server
Web server
Blackboard server
Mail server.
How do the other 4000 computers communicate?

20. Internal Sub-netting
Internet (All Real IPs in the World)
Outside of Siena, you can’t reach computer A and B directly.
Instead, you contact the router (Real IP) and also indicate A or B’s Internal IP.
Time Warner (Real IP)
Siena Gateway Router (Real IP) A B
Internal IP
Internal IP

21. Internal Sub-netting
Internet (All Real IPs in the World) C
Siena’s router is programmed so that A and B can directly communicate using Internal IPs (sub-net).
If A needs to reach a computer C outside of Siena, then the router modifies the packet headers to indicate the Siena Router’s Real IP address and the Internal IP of A.
Thus, C will know how to reach A.
Time Warner (Real IP)
Siena Gateway Router (Real IP) A
Internal IP B
Internal IP

22. Part 1: Activities
Traceroute
Lookup
Whois
Ping
Finger
Port Scan

23. Part 2: World Wide Web (WWW)
Remember: There are companies that use the Internet to connect two computers, yet these computers are not part of the WWW.
To be part of the world wide web, you need a URL
Uniform Resource Locator (not universal)

24. URL examples mailto:ebreimer@siena.edu http://www.cs.siena.edu
ftp://ftp.mit.edu/public/data.db

25. URL Concept Internet IP Address are meaningless
There is no organization
No geographic significance
No organizational significance
Create a meaningful name that is an alias for an IP Address
Given a URL create a system to find the IP Address (DNS lookup).

26. URL Breakdown http://www.cs.siena.edu Main Network – Domain Name
Sub-Network (optional)
Server Name
Top Level Domain Name
Protocol

27. Top-level Domain Names
Top Level Domains
.com
.net
.org
.edu
.mobi
.gov
.mil
U.S. - centric
Country Domains
.cn
.ca
.de
.au
Combinations
.com.au
.edu.au

28. Domain Name Hierarchies
root Name Server (NS)
.com NS
.edu NS
.net NS
siena.edu NS
mit.edu NS
harvard.edu NS
imail.siena.edu
cs.siena.edu NS
sos.siena.edu NS
ares.cs.siena.edu
turing.cs.siena.edu

29. Domain Name Hierarchies

30. ICANN Internet Corporation for Assigned Numbers and Networks.
Global coordinator of IP Address and Domain names.
Registrars like GoDaddy are “licensed” by ICANN to register domain names.
Large Internet Providers (ISPs) also “secure” IP addresses and farm them out to smaller ISPs.

31. Map of the Internet (US)
The above is a partial map as seen from one location (Lumeta.com).

32. USA: Pioneers of the Internet
The United States pioneered the Internet, and thus, “owns” the largest chunk of the infrastructure.
Western Europe, Japan, and Australia were quick to follow.
Eastern Europe, Russia and China are just getting established
Parts of Asia are next: India
South America is coming along
Africa may be decades away

33. Part 2: Activities
Do some surfing and try to find a URL with a sub-domain.
How much does it cost to register a domain name for .com, .net, .us?
Thinking of registering a domain name for your project? See if the one you want is available?

34. Client Server Model
The WWW uses this model exclusively.

35. Protocols of the WWW
HTTP / HTTPS – Hypertext Transfer Protocol (Secure)
FTP / SFTP – (Secure) File Transfer Protocol
SMTP – Simple Mail Transfer Protocol
POP – Post Office Protocol
IMAP – Internet Message Access Protocol
Telnet – Terminal Emulation

36. Big Picture Other countries? Albany
Clients / Visitors Potential Customers Potential Revenue
FTP / SFTP
Host Monster Web Server Utah
Internet
USA
HTTP / HTTPS
You – The Developer / The Designer

37. Big Picture Clients / Visitors Potential Customers Potential Revenue
HTML Documents (Production)
Application Support Services
Message Board Service
Payment Systems, Chat Server,
Internet
Host Monster Web Server Utah
You – The Developer / The Designer
HTML Documents (Development)
HTML Editor
Image Editor
Other Development Software
HTTP / HTTPS
FTP / SFTP

38. Big Picture Hostmonster Server HTML Documents (Development)
Steal other websites designs
HTML Editor
Dreamweaver
Image Editor
Fireworks
Other Development Software
Flash
Word
Excel
Internet
You – The Developer / The Designer
Hostmonster Control Panel
HTTP / HTTPS
FTP, SFTP, or SCP Client
FTP / SFTP

39. Key Technologies Hypertext – HTML – Hypertext Markup Language
Markups are used to structure a web page
CSS – Cascading Style Sheets
Styles are defined that decorate each structural element

40. DNS
Domain Name System
The WWW is supported by a network of DNS servers
These server help translate URLs into IP Addresses.
Domain Names are a fundamental concept that is connected to E-commerce.

41. Why are Domain Name so important?

42. Setting up a web server The old way Buy a computer (The Web Server)
Get an static IP Address from your ISP
Install Web Server software
Register a domain name with ICANN
Have your ISP update their DNS server.

43. Setting up a web server The NEW way
Buy a computer (for creating web pages)
Pay for hosting service (Web Server + DNS services).
Get the name of the DNS server.
Register a domain name with Registrar
Tell the registrar the name of the DNS server that your hosting service is using.

44. DNS Services vs. Hosting
ICANN coordinates this effort (1st party)
Companies (2nd party) need domain names.
3rd parties registrars actually manage domain name registration.
Registrars: goDaddy, Network Solutions, Yahoo
Hosting Services