Transcript powerpoint-slides, based on material written by Olga Gelbart

Technology Infrastructure for
Electronic Commerce
Olga Gelbart
[email protected]
THE GEORGE WASHINGTON UNIVERSITY
based on Prof. Lance Hoffman’s Lecture on Network Infrastructure for Electronic Commerce
Snapshots of the Electronic Commerce
World
• Yesterday - EDI
• Today - getting our toes wet, what this course is about
• Tomorrow - Metadata, machine understandable
information on the Web.
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Catalog information
Intellectual property information
Endorsement Information
Privacy information
see www.w3c.org/pics and www.w3c.org/p3p
How Did We Get Here?
• Before the Internet
– History of Commerce and Money
– Elements of payment systems
• The Start of the Internet
– Predecessor Networks
– Timeline of Significant Events
• The Internet Today
– What is the Internet?
– How Does the Internet Work?
– Differences from Original Net
– Differences from Traditional World Out There
• The Internet in the Future
What is the Internet?
• On October 24, 1995, the FNC unanimously passed a resolution
defining the term Internet. This definition was developed in
consultation with members of the internet and intellectual property
rights communities. RESOLUTION: The Federal Networking Council
(FNC) agrees that the following language reflects our definition of the
term "Internet". "Internet" refers to the global information system that
-- (i) is logically linked together by a globally unique address space
based on the Internet Protocol (IP) or its subsequent
extensions/follow-ons; (ii) is able to support communications using the
Transmission Control Protocol/Internet Protocol (TCP/IP) suite or its
subsequent extensions/follow-ons, and/or other IP-compatible
protocols; and (iii) provides, uses or makes accessible, either publicly
or privately, high level services layered on the communications and
related infrastructure described herein.
• http://www.fnc.gov/Internet_res.html
The Internet - connections
Computers in the backbone connected by a (T3) data
connection (45 megabits /second)
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ISP hosts and other powerful computers connect using
(T1,Broadband) lines
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Leased lines (some business)
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Modem dial-up connections
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Cable modems
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ADSL -- Asymmetric Digital Subscriber Line
Internet features
• Originally ARPAnet
– MIT, MITRE, SRI, BBN
– Distributed communications even with many failure
points
– Dissimilar computers exchange info easily
– Route around nonfunctioning parts
– 4 sites: SRI, UCLA, UCSB, Univ of Utah
• Hafner and Lyon, Where Wizards Stay Up Late, Simon &
Schuster 1996
Kahn’s Internet Principles
R. Kahn, Communications Principles for Operating Systems. Internal BBN memorandum, Jan.
1972.
• Each network must stand on its own and no internal
changes could be required to connect it to the Internet
• If a transmission failed, try again
• Simple black boxes (later called “gateways” and “routers”
would connect the networks
• No global control at operations level
The Internet - development
1962 Licklider, J.C.R., Galactic Network memos
Licklider - MIT to ARPA
ARPANET and successors: open architecture networking
1970s: universities and other DoD contractors connect
packets rather than circuits (note many of the names in
the articles were graduate students then)
1975: 100 sites and e-mail is changing how people collaborate
Late 1970s: New Packet Switching Protocol:
Transfer Control Protocol/Internet Protocol (TCP/IP)
1980: MILNET takes over military traffic
1980s: NSFNet links together NSF researcgers,
Internet protocols incorporated into (BSD) Unix, a widespread operating system
Late 1980s: NSFNet absorbs original ARPANET (for a US university to get NSF
funding for an Internet connection, that connection had to be made available to
all qualified users on campus, regardless of discipline
1995: Commercial backbones replace NSFNet backbone
Usenet
BITNET
Commercial Networks: AOL, Compuserve, etc.
Federal Decisions that Shaped the Internet
• Agencies shared cost of common infrastructure, e.g., transoceanic circuits
• CSNET/NSF (Farber) and ARPA (Kahn) shared
infrastructure without metering
• Acceptable Use Policy - no commercialization. Privately
funded augmentation for commercial uses (PSI, UUNET,
etc.), thought about as early as 1988 KSG conferences
sponsored by NSF
• NSF defunded NSF backbone in 1995, redistributing funds
to regional networks to buy from now-numerous, private,
long-haul networks
• NSFNet $200M from 1986-1995
The Internet - Four Aspects
Leiner, et al., “A Brief History of the Internet”, http://info.isoc.org/internet/history/brief.html
• Technological Evolution
– Packet Switching
– Scale, Performance, Functionality
• Operations and management of a global and complex
infrastructure
• Social Aspect - Internauts
• Commercialization
Internet Development Timeline
From “A Brief History of the Internet” by B. Leiner, et al.,
http://info.isoc.org/internet/history/brief.html
Excerpts from
Hobbes’ Internet Timeline
by Robert H. Zakon
http://www.info.isoc.org/guest/zakon/Internet/History/HIT.html
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1957 Sputnik; US forms ARPA
1962 P Baran, Rand, “On Distributed Communications Networks”, packet switched networks
1967 Larry Roberts first design paper on ARPAnet
1969 ARPANet commissioned. First RFC.
1970 ALOHANet (radio) connected to ARPANet in 1972
1971 Ray Tomlinson E-mail, BBN
1972 Telnet specification (RFC 318)
1973 File transfer specification (RFC 454)
1977 Mail specification (RFC 733)
1979 USENet newsgroups. First MUD.
1981 CSNet
1982 DoD standardizes on TCP/IP
1983 Name server developed at University of Wisconsin; users no longer need to remember exact path to other systems
1983 Berkeley releases 4.2BSD including TCP/IP
1984 DNS introduced. Now over 1,000 hosts
1984 Moderated newsgroups on USENET
1988 Internet worm affects 6,000 of the 60,000 Internet hosts
1990 EFF founded by Mitch Kapor
1991 WWW released by CERN (Tim Berners-Lee, developer)
1991 PGP released by Phil Zimmerman
1992 ISOC chartered
1992 “Surfing the Internet” coined by Jean Armour Polly
1993 US White House goes online
1993 Internet Talk Radio
1994 Can now order pizza from Pizza Hut online
1994 First Virtual bank open for business
1995 RealAudio
1995 Netscape third largest ever NASDAQ IPO share value
1995 Registration of domain names no longer free
1996 Communications Decency Act passed, challenged in US
1997 CDA overturned by Supreme Court
Growth of the Internet
From Hobbes’ Internet Timeline at http://info.isoc.org. ...
How Internet Manages Change?
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RFC process
W3C process
Now a proliferation of stakeholders
Debates over control of name space
Profits to be made and lost
Commercial vs. Other interests
Trends in Internet Applications
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Internet TV (Web TV + VIATV Videophone)
Voice over IP (VoIP)
Internet telephone
Internet dashboard (Alpine GPS, Windows CE in cars)
Wireless (WAP)
Internet: Big Picture
How Internet Works: Packets
HTTP: Hypertext Transfer Protocol
1. User clicks on link in browser.
2. Browser examines URL and gets
IP address of destination (website).
3. Browser sends HTTP request to
website.
4. Webserver is already listening at
port.
5. Webserver looks at request and
extracts filename.
6. Webserver sends entire file to
browser.
7. Browser decodes (parses) HTML
and displays.
8. Browser makes additional
requests as needed (images etc).
TCP/IP
• IP: Internet Protocol (handles packets)
• TCP: Transmission Controls Protocol
(handles connections)
Sending Form Data (parameters)
1. User fills in Form (text, buttons etc).
2. User clicks on submit.
3. Browser collects Form data.
4. Browser extracts URL buried in Form (not always visible to user).
5. Browser sends request and parameters to webserver.
6. Webserver is listening on port.
7. Webserver extracts Form data.
8. Webserver fires up locally-residing program (CGI) and hands over
Form data (parameters).
9. CGI program computes output and gives it to webserver.
10. Webserver sends output back to Browser.
11. Browser displays output.