e Commerce Technology 20 751 Lecture 2 e

e. Commerce Technology 20 -751 Lecture 2: e. Commerce Infrastructure

e. Commerce Infrastructure • Most of commerce (and e. Commerce) 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

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

Internet Leverage by Country WORLD TOTAL USERS (AUG. 2003): 700, 000 Rank Country Users % of World Leverage 166 M 25. 0 4. 52 5. 55 1 U. S. 2 Japan 56 M 8. 4 2. 05 4. 20 3 China 46 M 7. 0 20. 97 0. 33 4 U. K. 35 M 5. 3 0. 97 5. 46 5 Germany 32 M 4. 8 1. 34 3. 58 6 S. Korea 26 M 3. 9 0. 78 5. 00 7 Italy 20 M 3. 0 0. 93 3. 23 8 Russia 18 M 2. 7 2. 34 1. 15 9 France 17 M 2. 6 0. 97 2. 68 10 Canada 17 M 2. 6 0. 51 5. 10 11 Brazil 14 M 2. 1 2. 84 0. 74 12 Australia 11 M 1. 7 0. 32 5. 31 13 Netherlands 10 M 1. 5 0. 26 5. 77 LEVERAGE = % OF INTERNET USERS ÷ % OF WORLD POPULATION

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 56 K bps takes 143 sec. • 1 GB = gigabyte takes 40 hours – at 7 Mbps 19 minutes; at 1 Gbps takes 8 seconds) • Latency = delay from first bit transmitted to first received

Bandwidth Chart Bandwidth 1 Terabit O P T I C A L C O P P E R Technology Application DWDM Fiber (experimental) All U. S. phone conversations OC-192 Metropolitan Area Ethernet (MAE) OC-48 Long-haul Internet backbone Gigabit Ethernet 622 Mbps OC-12, Full-motion HDTV uncompressed 500 Mbps USB 2. 0, UWB limit 155 Mbps OC-3, FDDI Internet backbone 100 Mbps Fast Ethernet 50 Mbps 802. 11 a, Wi-Fi Virtual reality 44. 7 Mbps T 3 Medical imaging 11 Mbps 802. 11 b, Wireless LAN 6. 1 Mbps ADSL download Video conferencing, multimedia 802. 11, Bluetooth limit Old wireless LAN 1. 44 Mbps T 1 Streaming Video 128 Kbps ISDN 64 Kbps Telephone PCM Voice traffic 56 Kbps Modem Web browsing (slow) 30 bps Human speech • 10 A Gbps 2. 5 Gbps 1 Gbps 2 Mbps

LINK

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

European Interconnection Structure SOURCE: CYBERGEOGRAPHY. ORG

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

Connecting to the Internet Services Advanced Research Backbone Internet 2, Abilene, Interplanetary Internet Giga. POPs Network Service Providers (NSP) CA NAP Cable& Wireless Sprintlink NAPs, IXPs, Peering MAE east Internet Service Providers Chicago NAP UUnet LINX London NY NAP AT&T Worldnet Verizon/ GTE HKIX Qwest KIX Korea Top-tier ISP SOURCE: SAMIR CHATERJEE Lower tier ISPs 20 -751 ECOMMERCE TECHNOLOGY DC NAP FALL 2003 Price COPYRIGHT © 2003 MICHAEL I. SHAMOS

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

Fiber Optic Cables SOURCE: SURFNET. NL

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 20 -751 ECOMMERCE TECHNOLOGY FALL 2003 COPYRIGHT © 2003 MICHAEL I. SHAMOS

Optical Fiber Capacity Growth 1983 -2002 World record ~ 16 terabits per second 1, 400 OC-192, 128 l 1, 200 1 Terabit = 1, 000 Single Fiber Capacity (Gigabits/sec) OC-192, 80 l 800 600 OC-192, 48 l 400 OC-192, 32 l OC-48, 96 l OC-192, 16 l OC-48, 40 l OC-192, 2 l OC-192 200 20 -751 ECOMMERCE TECHNOLOGY FALL 2003 93 19 94 19 95 19 96 19 97 19 98 19 99 19 92 19 91 19 90 19 89 OC-48 19 87 1. 7 Gb 19 19 86 565 Mb 85 19 19 19 83 0 84 135 Mb COPYRIGHT © 2003 MICHAEL I. SHAMOS

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

Submarine Cables in North East Asia SOURCE: ALCATEL

Submarine Cables in North East Asia

Africa-One Submarine Network SOURCE: AFRICAONE

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

Bizar. Net Satellite Coverage

Circuit Switching v. Packet Switching SOURCE SWITCH SWITCH SWITCH SWITCH DESTINATION PACKET-SWITCHED NETWORK CIRCUIT-SWITCHED NETWORK 20 -751 ECOMMERCE TECHNOLOGY FALL 2003 COPYRIGHT © 2003 MICHAEL I. SHAMOS

Network Topologies • More than two computers causes complications: 1 2 3 4 LAN BUS TOPOLOGY 5 LAN = LOCAL AREA NETWORK • 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

Routing Machine 1. 35 wants to send a packet to Machine 3. 249. Machine 2. 16 Routers determine the path the packet will take. Machine 1. 35 Machine 3. 249 B A Router A can send the packet either way NUMBER OF ROUTES 20 -751 ECOMMERCE TECHNOLOGY 4. 1 NETWORK 4 & IT’S ROUTER FALL 2003 5. 9 COPYRIGHT © 2003 MICHAEL I. SHAMOS

Routers SIEMENS NORTEL 3 COM 20 -751 ECOMMERCE TECHNOLOGY CISCO FALL 2003 COPYRIGHT © 2003 MICHAEL I. SHAMOS

IPv 4 Header 20 -751 ECOMMERCE TECHNOLOGY FALL 2003 COPYRIGHT © 2003 MICHAEL I. SHAMOS

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

Packet Switching (TCP/IP)

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 1000000010 11011010 00000010 • Current max number of IP addresses = 232 ~ 4, 000, 000

IPv 6 • Increases # of IP addresses from 232 ≈ 4 billion to 2128 ≈ 1039 • Designed for faster routing • Supports Quality of Service (Qo. S), packet priorities • Allows multiple streams to the same IP address, e. g. audio, video, HTML

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 AMAZON . COM MCKINSEY . MIL YAHOO . NET . EDU CMU PITT . ORG . IT MIT 208. 216. 182. 15 207. 237. 113. 94 GSIA WWW 128. 2. 16. 175 YEN CS ECOM EURO 128. 2. 218. 2 HEINZ DOLLAR PESO 128. 2. 218. 4

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

URL: Two Hierarchies Spliced euro. ecom. cmu. edu/program/courses/tcr 751 ROOT. GOV AMAZON . COM MCKINSEY . MIL . NET CMU YAHOO GSIA FQDN . EDU YEN CS . ORG PITT ECOM EURO . IT MIT HEINZ DOLLAR PESO 128. 2. 218. 2 ABOUT AFFILIATES HOST DIRECTORY PEOPLE PROGRAM COURSES tcr 751 index. html tcr 753 tcr 770 tcr 870

Q&A 20 -751 ECOMMERCE TECHNOLOGY FALL 2003 COPYRIGHT © 2003 MICHAEL I. SHAMOS