Transcript No Slide Title

Electronic Commerce
Internet Hardware, Software and
Communications
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Outline
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Internet Infrastructure
Hardware
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Connecting to the Internet
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Servers
Communications
Storage Area Networks
Digital Subscriber Lines
Cable modems
Broadband, T-1, T-3 lines and faster connections
Wireless technologies
Internet2, next generation Internet
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Outline (cont.)
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Software
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Operating Systems
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Application layer
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E-mail, FTP, telnet, Web browser
Enhancing business communications
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UNIX, Microsoft Windows, Linux, Mac OS
Intranets and extranets
Streaming audio and video
Internet telephony
Web casting and Web conferencing
Application Service Providers (ASPs)
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Internet Infrastructure
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The architecture
The protocols
The software
The hardware
Communication process
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Internet Architecture
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A network of networks using a common set of
protocols
Networks comprise addressable devices or
nodes
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User workstations – clients
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Internet appliances
Servers
Intermediating nodes (e.g. routers, bridges,
domain-name servers)
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Millions of Clients and Servers
Server machine
running a Web server
Client machine running
a Web browser
The client connects to
the server and
requests a page
The server sends back
the requested page
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Typical Act of Viewing
Involves sending at least a dozen packets of
information over at least five separate networks:
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from your computer to your ISP
from your ISP to one of the national backbone providers (in
U.S. usually MCI, BBN, or Sprint)
from the backbone provider through one of the national
peering locations to another backbone provider
from the second backbone provider to the Web site’s ISP
from the Web site’s ISP to the Web server
Then, the process runs in reverse
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Unique Node Identifiers
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IP address
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IPv4 – 32 bit address
IPv6 – 128 bit address
340,282,366,920,938,463,463,374,607,431,768,211,456
different IP addresses
 If the world population were 10 billion, there would be
3.4*1027 addresses per person
20 addresses per square centimeter on the surface
 2.2*10
of the Earth
Other improvements: multicast, anycast, quality-of-service,
authentication and privacy capabilities (check here for
details)
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Communication Channels
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Copper wire (“twisted pair”)
Co-axial cable
Fiber-optic cable
Wireless
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Microwave links
Cellular, 2.5G, 3G
Satellite
IEEE 802.11b, Bluetooth
“The last kilometer” issue
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The Backbone
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High-speed fiber-optic cables shuttling information through the
Internet
Major Internet backbone providers: MCI, AOL Time Warner,
Sprint, MFS Data Services/UUNET, AT&T, BBN Planet, America
Online, CompuServe
Hubs reroute data packets at the intersections of high-speed
lines
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Metropolitan Area Exchanges (MAEs) are maintained for profit by
companies like MFS Data Services/UUNET
Network Access Points (NAPs) act as intersections but are
chartered by the NSF to Pacific Bell, Sprint, Ameritech and MFS
Data Services/UUNET
Check UUNET’s network map
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How Internet Works?
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Internet Governance
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Internet Architecture Board
Internet Engineering Task Force
Internet Engineering Steering Group
Internet Society
Internet Corporation for Assigned Names and
Numbers
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Domain Name System
IP addresses are difficult to remember
 Host names map to IP addresses
Example:
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www.ksu.ru
Server
name
Domain
name
Top level
domain name
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Domain Names
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Top level domains (TLD)
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com, org, edu, net, int, mil, gov
Country codes from ISO-3166
ICANN recently accepted seven new TLDs: aero,
biz, coop, info, museum, name, pro
Persistent host name
Dynamic IP address allocation
DNS information is distributed across
thousands of servers
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ICANN
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Internet Corporation for Assigned Names and
Numbers
ICANN accredited registrars
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Eighty-two accredited and operational (as of July 11)
Additional 66 accredited, but not yet operational
Many issues still unresolved
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Trademark protection
Network Solutions/VeriSign
Authority of ICANN
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Many Causes of Latency
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Modem malaise
Backbone bottleneck
Malfunctioning MAEs
Roundabout routing
Swamped sites
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Putting it all Together
With volume doubling every
nine months, the hub and
backbone system that
governs Internet traffic is
increasingly overloaded. In
this example, A must take a
complex route to site B,
contending with cross traffic
all along the way.
Most home PCs
connect at 56.6
Kbps or slower-making
downloading
daunting.
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Servers are
quickly
overwhelmed
on popular
sites.
Routing computers slow
down when volume rises,
especially when data
routers are complex.
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Common
bottlenecks
Traffic on the Internet: A Graphic Glossary
WHO’S CONNECTED . . .
. . . AND HOW
Internet Service Providers buy
bandwidth and re-sell it to
individuals and institutions.
Internet backbones are superfast, high capacity fiber-optic
lines that connect to hubs.
Institutions like businesses,
universities and governments
also buy direct connections.
Routers direct traffic from
hubs.
Servers offering information that
can be downloaded are
maintained by service providers
or the institutions themselves.
Individuals almost always
connect through a service
provider.
Hubs
Metropolitan Access Exchanges
(MAEs) are maintained for a profit
by companies like MFS Data
Services/UUNET. They sell
bandwidth to service providers.
Network Access Points (NAPs)
act as intersections, like
MAEs, but are chartered by the
National Science Foundation.
Storage Area Networks
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Companies collect large volumes of data
Storage Area Network (SAN)
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High-capacity, reliable data storage and delivery
over the networks
Data servers can be distributed
Store large volumes of data
Provides backup and recovery functions
Mirroring technology (redundant copies of data)
Fiber-optic technology for high-speed data transfer
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Enhancing Business
Communication
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Intranets, extranets
Streaming audio and video
Internet telephony
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Makes PC-to-PC, PC-to-phone and phone-to-phone
calls possible, dramatically reducing the cost of
communication
Web casting
Virtual conferencing
Wireless technology, working anywhere
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Application Service Providers
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Provide customized business software
applications over the Internet
Maintain and update applications
Companies can lower the costs
Involve the use of Virtual Private Networks
(VPNs)
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Internet, Intranet, Extranet,
VPN
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Role of firewalls
Security and encryption
Tunneling technologies
Intranet functions
Extranet applications
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Electronic data interchange (EDI)
Electronic funds transfer (EFT)
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Shopper/Purchaser
Seller/Supplier
Product/service information request
Purchase request
Payment or payment advice
Response to information request
Purchase acknowledgment
Shipping notice
Purchase/service delivery (if online)
Payment acknowledgment
Electronic Market
(Transaction Hander)
Response to fulfillment request
Shipping notice
Payment remittance notice
Electronic transfer of funds
Payment approval
Electronic transfer of funds
Shopper/Purchaser’s Bank
Purchase fulfillment request
Purchase change request
Electronic transfer of funds
Transaction Handler’s Bank
(Automated Clearing House)
Electronic Markets
Seller/Supplier’s Bank
Electronic Market
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A market is a network of interactions and
relationships where information, products, services,
and payments are exchanged
The market handles all the necessary transactions
An electronic market is a place where shoppers and
sellers meet electronically
In electronic markets, sellers and buyers negotiate,
submit bids, agree on an order, and finish the
execution on- or off-line
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Extranet Benefits
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Business enhancements
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Shorter time to market
Simultaneous engineering
Lower design and production costs
Improved customer relationships
New business opportunities
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Extranet Benefits (cont.)
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Cost reduction
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Reduced errors
Improved comparison shopping
Reduced travel, meeting expenses
Reduced administrative and operational costs
Elimination of paper publishing costs
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Extranet Benefits (cont.)
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Information delivery
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Low-cost publishing
Leveraging of legacy systems
Standard delivery systems
Ease of implementation and maintenance
Elimination of mailing costs
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Virtual Private Network
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Secure communication over the Internet is
enabled by:
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Point-to-point tunneling protocol creates a secure
channel over the public network
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Data in IP packets is encapsulated to hide the underlying
routing and switching infrastructure
Firewall restricts communication between internal
networks and the Internet
Encryption
Authentication
Database access authorization
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Tunneling
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Two types of tunneling
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Four protocols have been suggested:
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LAN-to-LAN - works transparently
client-to-LAN - requires special client software
Point-to-Point Tunneling Protocol (PPTP)
Multiprotocol Label Switching (MPLS); IETF
Layer Two Tunneling Protocol (L2TP)
IP Security (IPSec); IETF
For details, see for example a VPNs Tutorial
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