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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 –
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CE80NIntroduction to Networks&The Internet Dr. Chane L. Fullmer UCSC Winter 2002
New 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 CE80N -- Winter 2002 -- Lecture #4
Homework • Must be turned in during – • Class lecture • Session • TA Office Hour CE80N -- Winter 2002 -- Lecture #4
Today’s Reading • Chapter 8, Internet: The Early Years; • Chapter 9, Two Decades of Incredible Growth; • Chapter 10, The Global Internet; • Chapter 11, the Information CE80N -- Winter 2002 -- Lecture #4
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 CE80N -- Winter 2002 -- Lecture #4
The 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. CE80N -- Winter 2002 -- Lecture #4
The Early Years… • LAN technologies are basically incompatible • Electrically: • Voltage, frequency, speed • Protocol • Encoding • Other LAN limitations • distance CE80N -- Winter 2002 -- Lecture #4
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 CE80N -- Winter 2002 -- Lecture #4
The 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 CE80N -- Winter 2002 -- Lecture #4
The Early Years WAN G2 G1 G3 G2 CE80N -- Winter 2002 -- Lecture #4
The 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. CE80N -- Winter 2002 -- Lecture #4
The 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 access • A single cohesive network was desirable. CE80N -- Winter 2002 -- Lecture #4
The 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. CE80N -- Winter 2002 -- Lecture #4
The 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 CE80N -- Winter 2002 -- Lecture #4
The Early Years ARPANET Backbone G2 MIT LAN G1 UCB LAN DARPA LAN UCLA LAN G3 G2 CE80N -- Winter 2002 -- Lecture #4
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 CE80N -- Winter 2002 -- Lecture #4
The 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 CE80N -- Winter 2002 -- Lecture #4
The 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 CE80N -- Winter 2002 -- Lecture #4
The 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) CE80N -- Winter 2002 -- Lecture #4
The 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. CE80N -- Winter 2002 -- Lecture #4
The 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.. CE80N -- Winter 2002 -- Lecture #4
The 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 CE80N -- Winter 2002 -- Lecture #4
The 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 CE80N -- Winter 2002 -- Lecture #4
The 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… CE80N -- Winter 2002 -- Lecture #4
The 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 CE80N -- Winter 2002 -- Lecture #4
The 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 CE80N -- Winter 2002 -- Lecture #4
The 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 CE80N -- Winter 2002 -- Lecture #4
The Early Years • Exponential growth ……. CE80N -- Winter 2002 -- Lecture #4
The 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…. CE80N -- Winter 2002 -- Lecture #4
The 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. CE80N -- Winter 2002 -- Lecture #4
The Early Years • The Hard limit – Address space • The IP protocol is limited to a number contained in 4 bytes (32 bits)… Byte 3 Byte 2 Byte 1 Byte 0 • This limits the number of possibilities to 232 = 4,294,967,296 • There are solutions – IPv6, NAT CE80N -- Winter 2002 -- Lecture #4
The 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. CE80N -- Winter 2002 -- Lecture #4
The 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 CE80N -- Winter 2002 -- Lecture #4
The 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 CE80N -- Winter 2002 -- Lecture #4
Glossary • ARPA • Abbreviation for Advanced Research Projects Agency. • Backbone Network • Used to refer to a central network to which many routers connect. CE80N -- Winter 2002 -- Lecture #4
Glossary • 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. CE80N -- Winter 2002 -- Lecture #4
Glossary • RFC • Abbreviation for Request For Comments. • TCP/IP • Literally, the name of protocols that specify how computers communicate on the Internet. CE80N -- Winter 2002 -- Lecture #4
Glossary • 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. CE80N -- Winter 2002 -- Lecture #4
Glossary • 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. CE80N -- Winter 2002 -- Lecture #4
Glossary • 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. CE80N -- Winter 2002 -- Lecture #4
Glossary • 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. CE80N -- Winter 2002 -- Lecture #4
Glossary • 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. CE80N -- Winter 2002 -- Lecture #4
The Global Internet CE80N -- Winter 2002 -- Lecture #4
The 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 CE80N -- Winter 2002 -- Lecture #4
The 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 CE80N -- Winter 2002 -- Lecture #4
The 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 CE80N -- Winter 2002 -- Lecture #4
Figure 10.2 The European Backbone CE80N -- Winter 2002 -- Lecture #4
The 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. CE80N -- Winter 2002 -- Lecture #4
The Global Internet • Infrastructure • New infrastructure makes new industries possible • Shipping • Railroads • Interstate highway system • Airlines CE80N -- Winter 2002 -- Lecture #4
The 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. CE80N -- Winter 2002 -- Lecture #4