Transcript Introduction to Networked Computing

Introduction to
Networked Computing
Computer Networks, Intranet,
Internet and Network Protocols
Minimal Network
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Terminal
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Terminal
Connection
• Speed:
• DTR – Data Transfer Rate or Data
Transmission Ratio
• bit/sec bps
Connection type
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Terminal
Terminal
Connection
• Dedicated
• Circuit Switched
• Packet Switched
Transfer Medium
• cable (phone)
• 9,6 - 56kbps
• 56 - ~400 kbps
• ethernet cable
• up to 10 Mbps
• up to 100 Mbps
• fiber optics
• 100 – 2-4 Gbps
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• IR (Infra Red)
• IrDA – up to 115000 bps
• IrTran – up to 2 Mbps
• Radio
• GSM 9,6 – 14,8 kbps
• HSCSD/GPRS 14,8 – 28 kbps
• 3G 2 - 4 Mbps
Transfer Type
Simplex
Semi-duplex
Duplex
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Network Architecture
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Client
Peer
Service requests
Services
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Server
Peer
Network Topology - Ring
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Network Topology - Star
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Network Types / Server Roles
LAN – Local Area Network ~ Intranet
WAN – Wide Area Network ~ Internet
WLAN – Wireless LAN
VPN – Virtual Private Network: Intranet over Internet
Router – directs data (packages) within a network
Gateway – connects networks
Name server – provides terminal addressing data
File Server – provides files for sharing
Application Server – provides shared programs
Network Layers
• APPLICATION LAYER
• Provide services (e-mail, remote control, ...)
• TRANSPORT LAYER
• Control the data transfer
• Security and reliablility
• NETWORK LAYER
• Establishing physical connection
• Control the link
• Control the data flow
Network Protocols
• NETWORK LAYER
• IP (internet Protocol) ARP, RARP (Addressing)
•TRANSPORT LAYER
• TCP (Transfer Control), UDP (Universal Datagram)
•APPLICATION LAYER
• Telnet, FTP – remote access
• SMTP, POP3, NNTP – email, news
• GOPHER, HTTP, HTTPS – world wide web
• LDAP, VoIP, ISDN – directory, voice and image
transmission
Internet Timeline 60’s
• 1961 There’s no Internet
• 1962 RAND Corporation starts research for robust
military communication networks
• 1963 Beatles plays for the Queen of England
• 1964 Dr Strangelove
• 1965 – 67 ARPANET plans and research (Dept. of
Defence Sdvanced Research and Project Agency)
• 1968 First generation of network hw/sw designed
• 1969 ARPANET connects Stanford, UCLA, UC Santa
Barbara, University of Utah
Internet Timeline 70’s
• 1970 ALOHANET at University of HAWAII
• 1970 – 73 ARPANET: Extends, first e-mail service
• 1973 ARPANET goes international: University College,
London and Royal Radar Establishment, Norway
• 1974 Telenet: First commercial version of ARPANET
• 1976 First Royal Email by Queen Elizabeth
• 1979 First USENET news groups started
Internet Timeline 80’s
• 1981 ARPANET has 231 hosts grows by 1 per every 20
days
• 1982 The term ‘Internet’ is used for the first time
• 1983 TCP/IP becomes de facto standard
• 1984 ‘Cyberspace’ appears in W Gibson’s Neuromancer
• 1985 E-mail spreads in most universities
• 1987 10,000+ hosts connected
• 1988 The Internet Worm
• 1989 100,000+ hosts connected
Internet Timeline early 90’s
• 1990 ARPANET is decomissioned, Internet remains
• 1991 The World Wide Web is born at CERN,
Switzerland (Tim Berners-Lee)
• 1991 Internet is freed (?) for commercial use
• 1991 University of Minnesota: the first GOPHER service
by Mark MaCahill („The first Internet application my mom
can use”)
• 1992 1,000,000+ hosts connected
• 1993 MOSAIC, the first graphical browser, is released
• 1994 Rolling Stones Voodoo Lounge on-line, First online pizza mushroom & pepperony from Pizza Hut
Internet Timeline mid-90’s
• 1995 Sun Microsystem releases Java
• 1996 150 countries connected
• US TelCo companies ask the Congress to ban
Internet phones
• 1997 Search engines appear
• Restrictions on Internet access:
• China: users must be registered with the police
• Saudi-Arabia: Only at universities and hospitals
• Singapore: political and religious content must be
registered with the state
Internet Timeline late 90’s
• 1998
• Web is estimated to be 250 to 320 million pages
• Electronic postal stamp from US Postal Service
• HTCPCP version 1.0 
• e-Commerce, Portals
• 1999
• Public access from Saudi-Arabia (.sa)
• First Internet Bank of Indiana
• Melissa e-mail worm
Internet Timeline
st
21
Century
• 2000
• y2k panic, WAP becomes fashionable
• 1 billion+ public webpages
• Internet2 backbone network
• NAPSTER lawsuits
• 2001
• e-mail forwarding illegal in Australia (4 March)
• European Council adopts Cybercrime Treaty (9 Nov)
• Pi Digit Generation Protocol, Electricity over IP 
• .museum begins resolving
Internet Growth
Domain Growth
WWW Growth