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CE80N Introduction to Networks & The Internet. Dr. Chane L. Fullmer UCSC Winter 2002. New Session Hours. Jack’s Lounge (1 st floor BE) Thursdays – 7:30 -> 8:30 PM TA Office Hours Tuesdays – 6:30 -> 7:30 PM Fridays – 1:00 -> 2:00 PM. Homework. Must be turned in during – - PowerPoint PPT Presentation
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CE80NCE80NIntroduction to NetworksIntroduction to Networks
&&The InternetThe Internet
Dr. Chane L. Fullmer
UCSC
Winter 2002
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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New Session HoursNew Session Hours
Jack’s Lounge (1st floor BE)–Thursdays – 7:30 -> 8:30 PM
TA Office Hours–Tuesdays – 6:30 -> 7:30 PM
–Fridays – 1:00 -> 2:00 PM
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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HomeworkHomework
Must be turned in during –– Class lecture– Session– TA Office Hour
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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Today’s ReadingToday’s Reading
Chapter 8, Internet: The Early Years; Chapter 9, Two Decades of Incredible
Growth; Chapter 10, The Global Internet; Chapter 11, the Information
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early Years…The Early Years…
A Multitude of Local Area Network (LAN) technologies exist --– Combinations of :
• Speed, reliability, cost, platform, etc..
– Performance determines cost• High speed costs more
– Platform dependency of Network Interface Card (NIC)
– Not all technologies are available across all platforms, restricting interoperability among certain platforms
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early YearsThe Early Years
Many autonomous groups installing independent networks– Allowed them to control access,
policies, etc..– Resulted in a proliferation of LAN
technologies from various vendors.
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early Years…The Early Years…
LAN technologies are basically incompatible– Electrically:
• Voltage, frequency, speed
– Protocol• Encoding
– Other LAN limitations• distance
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early Years…The Early Years…
Wide Area Networks (WAN)– First WANs used dialup technology to
form a set of long-haul transmission lines
– Uses a dedicated machine at each local site to unify the transmission lines into a coordinated system
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early YearsThe Early Years
A WAN differs from a disjoint set of transmission lines because of the inclusion of a special computer (Gateway) at each site that connects to the transmission lines and keeps communication independent of the computers that use the WAN
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early YearsThe Early Years
WAN
G1
G2
G2 G3
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early YearsThe Early Years
WANs are expensive to install and maintain– Leased transmission lines– Dedicated hardware
Again, many WAN and LAN technologies were developed, and incompatibilities continued to exist.
WANs are not compatible with LAN technology, and cannot directly interoperate.
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early YearsThe Early Years
Many WANs and LANs were installed, but machines on the WANs could not access information on the LANs..– Remote access was separated from local
accessA single cohesive network was
desirable.
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early YearsThe Early Years
US Department of Defense had a similar scenario – lots of autonomous networks that could not interoperate
The DoD funded network research in the early ’70s through (D)ARPA creating various network technologies, including a research WAN called ARPANET.
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early YearsThe Early Years
ARPANET allowed researchers the opportunity to build a working test-bed for networking ideas.– Solved incompatibility issues– Solved interoperability issues– Created an internetwork of LANs and
the WANs The Internet is born
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early YearsThe Early Years
ARPANETBackbone
UCLALAN
UCLALAN
MITLAN
MITLAN
UCBLAN
UCBLAN
DARPALAN
DARPALAN
G1
G2
G2 G3
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early Years…The Early Years…
Internet Software– Internet Protocol (IP)
• Provides basic communication
– Transmission Control Protocol (TCP)• Provides services for applications to
communicate
– The “TCP/IP Internet Protocol Suite”• aka TCP/IP
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early YearsThe Early Years
ARAPA placed the research and software into the public domain.– All information was freely available to any
person or vendor, allowing them to create devices or networks that would interoperate with the Internet technology.
– Improvements were documented and made publicly available.
– This philosophy is called an Open System
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early YearsThe Early Years
Internet documentation– On-line and accessible from the Internet– Reports for improvements to the Internet were
initially a two step process• Request for comments (RFC) went out first• Internet Engineering Note came out with the
comments as the final report.
– Today the RFC remains as the definitive documentation for the Internet
• On-line at www.faqs.org/rfcs/– Also www.ietf.org/rfc.html
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The Early YearsThe Early Years
The UNIX operating system – Built at Bell Labs in the early ’70s– UNIX given to universities to study– UC Berkeley team added LAN software
• Distributed to others via the Berkeley Software Distribution (BSD) and became known as BSD UNIX (The ancestor of today’s Free BSD)
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early YearsThe Early Years
ARPA negotiated with UCB to add the TCP/IP suite to the BSD UNIX release.– Gave large number of universities access to
study networking, and deploy it in their departments.
1982 the US Military chose the Internet as its primary communication system.
1983 the ARPANET began running TCP/IP exclusively.
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early YearsThe Early Years
Incredible growth from day one..– In 1982 ~200 machines were connected– By 1983 the number had doubled– With growth comes the problems..
• Static lists of machines need updated• Limited memory space …• Software updates..
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The Early YearsThe Early Years
The Computer Science Network (CSNET)– Sponsored by NSF in early `80s
• Goal was to connect every Computer Scientist in the country over one network.
• CSNET was deployed using TCP/IP and the Internet• By mid 1980s most major university and research
labs were connected to the Internet• Graduate students began to investigate the details of
these new technologies, and include them in their research topics.
– Developed new applications– Extended the technology
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early YearsThe Early Years
The IAB (Internet Activities Board)– Original controlling body to coordinate
TCP/IP research and Internet development.
• Chairman – Internet Architect• RFC Editor• Formed volunteer task forces to solve
problems– Task forces generated new RFCs
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early YearsThe Early Years
The IETF (Internet Engineering Task Force)– Originally chartered for short-term
Internet development.– Now is responsible for most of the
Internet technical development• Working groups meet and create the RFCs
– Manet, ipsec, tcp…
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early YearsThe Early Years
NSFNET– NSF recognized the importance of the
Internet to the scientific community.– Interconnected the supercomputer
centers around the US with a TCP/IP WAN
• Proved useful, but small• NSF looked for ways to improve the ARPA
Internet
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early YearsThe Early Years
The NSFNET Backbone– 1988 WAN established as main
backbone of the Internet• MCI – long distance transmission lines• IBM – dedicated computers and software• MERIT – network operation
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Early YearsThe Early Years
The ANS Backbone (Advanced Networks and Services)– Consortium of MCI, IBM & MERIT
• Allowed the government to begin privatization of the Internet
– 1992 – WAN was built to serve as the Internet backbone
• ANSNET, 30 times NSFNET capacity
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The Early YearsThe Early Years
Exponential growth …….
0
10000000
20000000
30000000
40000000
50000000
60000000
70000000
80000000
1983 1986 1989 1992 1995 1998 2001
ComputersConnected
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The Early YearsThe Early Years
By 1999, the Internet was growing so fast that, on average, a computer was added to the Internet every second – and the rate continues to increase.
An interesting fact:– At any time from 1983 through 1999, approximately half the
growth of the Internet occurred in the previous 12 months…
So, after you have been “on” the Internet for only one year, you will have had more experience than half the other users….
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The Early YearsThe Early Years
Growth – Good and Bad– Good for vendors– Bad for the IETF
• Predictions of imminent collapse– March 1993, Summer ’97
• Technology improvements have kept up with bandwidth and switching speeds required.
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The Early YearsThe Early Years
The Hard limit – Address space– The IP protocol is limited to a number
contained in 4 bytes (32 bits)…
Byte 0Byte 1Byte 2Byte 3
•This limits the number of possibilities to 232 = 4,294,967,296
•There are solutions – IPv6, NAT
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The Early YearsThe Early Years
Summary– The Internet began as an ARPA research
project.– The TCP/IP protocol software was developed
to make the Internet operational.– The Internet is an Open System, with the
technology freely available to all.– The Internet documentation is available on-line
in the form of reports known as RFCs.
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The Early YearsThe Early Years
Summary (continued)– BSD UNIX distributed TCP/IP suite freely to
universities in the early 80s– 1982 US Military adopted TCP/IP as primary
communication standard– Exponential growth from its inception– IAB formed to coordinate development– IETF - major technical development body
• Working groups
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The Early YearsThe Early Years
Summary (Continued)– 1988 – NSFNET Backbone– 1992 – Privatization (ANSNET)– Exponential growth from its inception
• Half of the users today have been there less than one year……
– IP Address 32 bit limitation
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GlossaryGlossaryGlossaryGlossary
ARPA– Abbreviation for Advanced Research Projects
Agency. Backbone Network
– Used to refer to a central network to which many routers connect.
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GlossaryGlossaryGlossaryGlossary
Internet– The collection of networks and routers
that use the TCP/IP protocol suite and function as a single, large network.
Open System– A non-proprietary technology or
system: any vendor can use the specifications of an open system to build products and services.
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GlossaryGlossaryGlossaryGlossary
RFC– Abbreviation for Request For Comments.
TCP/IP – Literally, the name of protocols that specify
how computers communicate on the Internet.
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GlossaryGlossaryGlossaryGlossary
TCP/IP Software– The name of the software that implements the
protocols. Wide Area Network (WAN)
– Any network technology that can span long geographic distances.
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GlossaryGlossary
ANSNET – A major Wide Area Network that formed part
of the Internet in the mid-1990s. Internet Architecture Board (IAB)
– Set policy and standards for TCP/IP and the connected Internet.
Internet Engineering Task Force (IETF) – Responsible for designing and testing new
technologies for TCP/IP and the Internet.
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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GlossaryGlossary
Internet Protocol (IP) – Specification for the format of packets computers
use when they communicate across the Internet. National Science Foundation (NSF)
– A U.S. government agency that has funded the development of a WAN for the Internet and helped scientists connect to the Internet.
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GlossaryGlossary National Science Foundation NETwork
(NSFNET)– The Wide Area Network that forms the
backbone of the Internet in the United States.
Operating System – Complex software that manages the
computer, control I/O devices, and provides file storage on multi-user computers.
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GlossaryGlossary
Request For Comments (RFC)– Series of notes that contain the TCP/IP
protocol standards. Transmission Control Protocol (TCP)
– One of the two major TCP/IP protocols. TCP handles the difficult task of ensuring that all data arrives at the destination in the correct order.
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Global The Global InternetInternet
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The Global InternetThe Global Internet
The Internet was originally sponsored by the US Government (through ARPA).– Efforts concentrated in the US– ARPA experimented with satellite
connections to test the Internet• Norway, England
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Global InternetThe Global Internet
Email – the first “killer app”– Began with dialup networks
• UNIX – UUCP (Unix to Unix Copy)• BITNET, FIDONET
– Dialup software could be used from most locations in the world.
• Telephone systems interoperate globally– ITU (International Telecommunication Union)
standards
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Global InternetThe Global Internet
European development– Research networks
• JANET (Joint Academic Network)• EARN (European Academic And Research
Network)
EBONE– 1991 – cooperative formed in Europe to
operate a WAN spanning Europe, and connecting to the US Internet
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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Figure 10.2 The European Backbone
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The Global InternetThe Global Internet
1997 – All seven continents are reached by the Internet – including Antarctica.
1998 – Total Globalization is achieved:– Every populated country in the world
has Internet access.
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Global InternetThe Global Internet
Infrastructure– New infrastructure makes new
industries possible• Shipping• Railroads• Interstate highway system• Airlines
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The Global InternetThe Global Internet
Communication Infrastructure– Messengers on foot/horseback– Postal mail system
• Universal delivery– Any individual can send a letter to any other
individual.– The scope of an infrastructure defines a closed
community that shares the benefits it offers.
– Telegraph system• Introduced high-speed delivery.
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Global InternetThe Global Internet
Communication Infrastructure (cont)– The Telephone system
• Extended instantaneous communication to individual homes and offices, and allowing interactive conversations.
• Wireless (cell) phones extend instantaneous communication to the individual directly, wherever they may be.
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Global InternetThe Global Internet
The Internet Infrastructure– Basic communications facilities are
general purpose• Almost any network application can use the
Internet
– Most of the services available were not invented when the Internet was conceived.
• Web browsers, Real Audio, email…
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The Global InternetThe Global Internet
Internet Infrastructure– The TCP/IP Suite is the key
• General purpose• Efficient• Flexible• Robust
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The Global InternetThe Global Internet
The Internet is a global information infrastructure.
Although it offers many services, the Internet’s chief advantage lies in the design of the TCP/IP software that has accommodated changes in computers, networks and services.
(And it has done so now, for 20+ years)
January 15, 2002 CE80N -- Winter 2002 -- Lecture #4
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The Global InternetThe Global Internet
Summary– Email was the first killer app.– EBONE brought Europe to the Internet– 1997 – Every continent is connected– 1998 – Every populated country is
connected– The Internet is the new infrastructure– TCP/IP is the key to how the Internet works.
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GlossaryGlossary
EBONE – (European backBONE) The Wide Area
Network facilities that interconnected many European countries to one another and to the Internet in the mid 1990s.
BITNET– (Because It’s Time NETwork) An early
network developed at City University of New York.
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GlossaryGlossary
ITU– Abbreviation for International Telecommunication
Union. PTT
– Abbreviation for Post, Telegraph, and Telephone.
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GlossaryGlossary
UUCP– (Unix to Unix Copy Program) Software developed
in the mid 1970s that allows one computer to copy files to or from another over a (usually dial-up) connection.
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GlossaryGlossary
Infrastructure– A service or facility that is fundamental to
society