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eCommerce Technology 20-751 Lecture 2: eCommerce Infrastructure

eCommerce Technology 20-751 Lecture 2: eCommerce Infrastructure. eCommerce Infrastructure. Most of commerce (and eCommerce) is exchange of information , not goods The most efficient way to move information (cost per bit) to a large number of destinations is the Internet

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eCommerce Technology 20-751 Lecture 2: eCommerce Infrastructure

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  1. eCommerce Technology20-751Lecture 2:eCommerce Infrastructure

  2. eCommerce Infrastructure • Most of commerce (and eCommerce) is exchange of information, not goods • The most efficient way to move information (cost per bit) to a large number of destinations is the Internet • Allows point-to-point communication with arbitrary people and companies • The Internet is getting bigger fast

  3. Internet Host Count 1991-2003 “Host”  computer than can be reached by a URL ESTIMATE: 300,000,000 hosts by 2005 172,000,000

  4. Internet Leverage by Country WORLD TOTAL USERS (AUG. 2003): 700,000,000 LEVERAGE = % OF INTERNET USERS ÷ % OF WORLD POPULATION

  5. Bandwidth Review • Bit (b) = a unit of information, 0 or 1 • 10 bits can represent 1024 different messages • 20 bits represent > 1 million • 30 bits > 1 billion messages • The bandwidth of a communication channel = number of bits per second it transmits • All channels have limited bandwidth • One byte (B) = 8 bits (an octet) • Transmitting 1 MB at 56K bps takes 143 sec. • 1 GB = gigabyte takes 40 hours • at 7Mbps 19 minutes; at 1 Gbps takes 8 seconds) • Latency = delay from first bit transmitted to first received

  6. Bandwidth Chart OPTICAL • A COPPER Units of Measurement

  7. LINK

  8. Regional A Australia Japan NAP NAP NAP NAP Europe Backbone 2 Backbone 4, 5, N Regional B Backbone 1 Backbone 3 Structure of the Internet MAPS UUNET MAP KOREA SOURCE: CISCO SYSTEMS

  9. European Interconnection Structure SOURCE: CYBERGEOGRAPHY.ORG

  10. Internet I Network Architecture SOURCE: LAUDON & TRAVER, p. 126

  11. Connecting to the Internet Services Advanced Research Backbone Internet2, Abilene, Interplanetary Internet GigaPOPs CA NAP Chicago NAP DC NAP NY NAP Network Service Providers (NSP) Sprintlink Cable& Wireless UUnet AT&T Worldnet Verizon/ GTE Qwest NAPs, IXPs, Peering MAE east LINX London HKIX KIX Korea Top-tier ISP Internet Service Providers SOURCE: SAMIRCHATERJEE Price Lower tier ISPs

  12. plastic jacket glass or plastic cladding fiber core Fiber Optics TOTAL INTERNAL REFLECTION

  13. Fiber Optic Cables SOURCE: SURFNET.NL

  14. Dense Wave-Division Multiplexing (DWDM) Multiple colors (frequencies) sent through the fiber at the same time, more than 100 Each color carries a separate signal Allows huge bandwidth

  15. 1,400 OC-192, 128l 1,200 1,000 1 Terabit = OC-192, 80l 800 Single Fiber Capacity (Gigabits/sec) 600 OC-192, 48l 400 OC-192, 32l OC-48, 96l OC-192, 16l 200 OC-48, 40l OC-192, 2l 565Mb 1.7 Gb OC-48 OC-192 135Mb 0 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 Optical Fiber Capacity Growth 1983-2002 World record ~ 16 terabits per second

  16. Fiber Optic Lines in Central Philadelphia TELECOM HOTEL SOURCE: CYBERGEOGRAPHY.ORG

  17. Submarine Cables in North East Asia SOURCE: ALCATEL

  18. Submarine Cables in North East Asia

  19. Africa-One Submarine Network SOURCE:AFRICAONE

  20. Telstar 10 Satellite Coverage Protocols • A dbW = DECIBELS RELATIVE TO ONE WATT EIRP = EFECTIVE ISOTROPIC RADIATED POWER E.L. = EAST LONGITUDE SOURCE:LORAL SKYNET

  21. BizarNet Satellite Coverage

  22. SOURCE SOURCE SWITCH SWITCH SWITCH SWITCH SWITCH SWITCH SWITCH SWITCH SWITCH SWITCH SWITCH SWITCH SWITCH SWITCH DESTINATION DESTINATION Circuit Switching v. Packet Switching PACKET-SWITCHED NETWORK CIRCUIT-SWITCHED NETWORK

  23. Network Topologies • More than two computers causes complications: • Each machine on a network must have a unique address • If machine 2 sends a message to machine 4, what tells 1, 3 and 5 to ignore it, but 4 to listen? • Ethernet protocol 1 2 4 5 3 LAN = LOCAL AREA NETWORK LAN BUS TOPOLOGY

  24. Routers Routing Machine 2.16 Machine 1.35 wants to send a packet to Machine 3.249. Routers determine the path the packet will take. Machine 3.249 B A Machine 1.35 Router A can send the packet either way 4.1 5.9 NETWORK 4 & IT’S ROUTER NUMBER OF ROUTES

  25. Routers SIEMENS NORTEL 3COM CISCO

  26. IPv4 Header

  27. Packet Switching (TCP/IP) TCP = TRANSMISSION CONTROL PROTOCOL (Breaks messages into packets and reassembles them) IP = INTERNET PROTOCOL (Moves packets around the Internet) SOURCE: J. DECEMBER

  28. Packet Switching (TCP/IP)

  29. IP Addresses • Machines on the Internet need an addressing scheme (or couldn’t receive packets!) • Each machine has a 32-bit address assigned by the Internet Corporation for Assigned Names and Numbers (ICANN). • In the U.S., American Registry for Internet Numbers (ARIN) • In Europe, Réseaux IP Européens (RIPE) • Addresses are written in dotted decimal notation: 128 . 2 . 218 . 2 10000000 00000010 11011010 00000010 • Current max number of IP addresses = 232 ~ 4,000,000,000

  30. IPv6 • Increases # of IP addresses from 232≈ 4 billion to 2128≈ 1039 • Designed for faster routing • Supports Quality of Service (QoS), packet priorities • Allows multiple streams to the same IP address, e.g. audio, video, HTML

  31. Domain Names • IP addresses are inconvenient to remember 128.2.218.2 v. euro.ecom.cmu.edu (fully qualified) • Domain names are alphanumeric aliases for IP addresses. They form a tree structure of FQDNs: ROOT .GOV .COM .MIL .NET .EDU .ORG .IT CMU PITT MIT AMAZON MCKINSEY YAHOO 208.216.182.15 207.237.113.94 GSIA CS ECOM HEINZ WWW YEN EURO DOLLAR PESO 128.2.218.4 128.2.218.2 128.2.16.175

  32. URL: Uniform Resource Locator • URL identifies a specific resource on a server in a domain • URL tells what protocol to use to access the resource • URL format: http://euro.ecom.cmu.edu/program/courses/index.shtml protocol://domain_name/path_name

  33. ROOT .GOV .COM .MIL .NET .EDU .ORG .IT CMU PITT MIT AMAZON MCKINSEY YAHOO GSIA CS ECOM HEINZ FQDN YEN EURO DOLLAR PESO 128.2.218.2 HOST DIRECTORY COURSES tcr751 tcr753 tcr770 tcr870 ABOUT AFFILIATES PEOPLE PROGRAM index.html URL: Two Hierarchies Spliced euro.ecom.cmu.edu/program/courses/tcr751

  34. Q A &

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