CS计算机代考程序代写 algorithm information theory FTP dns c/c++ Java COMPSCI 1511

COMPSCI 1511
Computer Networking

Outline
➢ Course information
What is network?
A brief introduction to the Internet: past and present
 Summary
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Course Information
 Textbook
 Computer Networking: A Top-Down Approach, by Kurose and Ross, any version beyond 2nd is OK
 Reference books
 Computer Networks,
by A. Tanenbaum, Prentice Hall
 An Engineering Approach to Computer Networking, S. Keshav, Addison-Wesley
 And more (see Web)
 Resource
 Find from L@PU
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What Are the Goals Of This Course?
Have fun!
 Are you happy with no Internet access in your life ?  Without the Internet, my computer is useless
Understand how network (in particular, the Internet) works
 Its applications
 Its design philosophy
 Its protocols and mechanisms
We emphasize on the fundamentals,
i.e., you know not only how to use a network, but know why it is designed this way
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Education style
There are some information to know  Either you know it or you don’t know it
There are some math
 Build up analysis skills
 Provide rigid support for the Internet
There are some design philosophy  Useful for other types of applications
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What Will We Cover? (Tentative schedule)
 Introduction (Jan 21st)
 Internet architecture and design philosophy
 Applications (Jan 28th, Feb 4th)  HTTP/WWW, DNS
 Transport services (Feb 4th, Feb 11th, Feb 25th, Mar 4th)  reliability; congestion control; transport protocols:
TCP/UDP
 Network services (Mar 11th, Mar 25th, Apr 1st)
 routing; network protocols: IP
 Mar 18th Exam 1
 Link & physical layers (Apr 1st Apr 8th Apr 15th)
 multiple access; Ethernet, hubs and bridges  Apr 22nd Exam 2
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What Will We Cover? (Tentative schedule)
 Lab Wireshark (week 3)
 Lab socket programming (week 4)  Lab HTTP programming (week 5)  Tutorial Chapter 1 (week 6)
 Tutorial Chapter 2 (week 7)
 Tutorial Chapter 3 (week 8)
 Tutorial Midterm (week 9)
 Lab DNS (week 10)
 Tutorial Chapter 4 (week 11)
 Lab TCP/IP (week 12)
 Tutorial Chapter 5 (week 13)
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What Do You Need To Do?
Your prerequisites
 algorithms: e.g., quick sort
 basic programming: C/C++ or Java
Our focus is not on network programming, it’s a byproduct
 basic concepts of operating systems Your workload
 read the book, (exam questions will be selected from the textbook)
 homework assignments
• A few written assignments • One programming project
 two in class exams
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Outline
Course information
➢ What is network?
❑A brief introduction to the Internet: past and present
 Summary
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Outline
Course information
What is network ?
➢ A brief introduction to the Internet ➢ past
 present  Summary
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A Brief History of the Internet
 1957
 USSR launches Sputnik, US formed Advanced Research Projects
Agency (ARPA) as a response
 1968
 Bolt Beranek and Newman, Inc. (BBN) was awarded Packet Switch contract to build Interface Message Processors (IMPs) for ARPANET
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A Brief History of the Internet
 1969
 ARPANET commissioned: 4 nodes, 50kbps
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Initial Expansion of the ARPANET
Dec. 1969 July 1970 March 1971
Apr. 1972
Sep. 1972
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Multiple Networks
 1974: Initial design of TCP to connect multiple networks
 1986: NSF builds NSFNET as backbone, links 6 supercomputer centers, 56 kbps; this allows an explosion of connections, especially from universities
 1987: 10,000 hosts  1989: 100,000 hosts
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Web and Commercialization of the Internet
 1991: NSF lifts restrictions on the commercial use of the Net; World Wide Web released
 1992: 1 million hosts
 Today: backbones run at 100Gbps, 700 millions
computers in 150 countries
 Internet history and Timeline
 http://www.zakon.org/robert/internet/timeline/
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Growth of the Internet
in Terms of Number of Hosts
Number of Hosts on the Internet:
1,000,000,000 100,000,000 10,000,000 1,000,000 100,000 10,000 1,000 100 10 1
1981 1984 1987 1990 1993 1996 1999 2002
Aug. 1981
Oct. 1984
Dec. 1987
Oct. 1990
Jul. 1993
Jul. 1996
Jul. 2000
Jul. 2002 162,128,493
213 1,024 28,174 313,000 1,776,000
19,540,000 93,047,000
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250,000,000 200,000,000 150,000,000 100,000,000
50,000,000
0
Chart by William F. Slater, III
Time Period
Growth of Internet Hosts * Sept. 1969 – Sept. 2002
Sept. 1, 2002
Dot-Com Bust Begins
The Internet was not known as “The Internet” until January 1984, at which time there were 1000 hosts that were all converted over to using TCP/IP.
Copyright 2002, William F. Slater, III, Chicago, IL, USA 17
No. of Hosts
9/69 01/71
01/73 01/74
01/76 01/79
08/81 08/83
10/85 11/86
07/88 01/89
10/89 01/91
10/91 04/92
10/92 04/93
10/93 07/94
01/95 01/96
01/97 01/98
01/99 01/01
08/02

Growth of the Internet
in Terms of Number of Hosts
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Killer applications – Email
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Killer applications – FTP
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Killer applications – WWW 1990-
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Killer applications – P2P 2000-
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Killer applications – what’s now and what’s next ?
 Media streaming (Internet TV)  YouTube
 E-commerce
 Ebay, Amazon
 Online game
 Cloud computing
 Internet of Things  Edge computing
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Internet Pioneers
Vannevar Bush (APARNet)
Claude Shannon (Information theory)
Paul Baran (Packet switching)
Leonard Kleinrock (Pakcet switching)
Ted Nelson (Hypertext)
Lawrence Roberts (APARNet)
Vinton Cerf (TCP/IP)
Robert Kahn (TCP/IP)
Tim Berners-Lee (WWW)
Mark Andreesen (Mosaic/Netscape)
Microsoft, Google, BitTorrent, YouTube …
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Why Internet ?
One of the most successful networks  Open
 Heterogeneous
• Interconnects different networks
 Simple network, complex end-terminals • Computer based
How about other networks?  Telephone
 Cable TV
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Summary
Course information
Network: nodes -> interconnected
Internet: The past:
 started as ARPANET: late 1960s
 initial link bandwidth: 50 kbps  number of hosts: 4
Internet: Current:
 number of hosts: grows at an exponential speed  backbone speed: 100+ Tbps
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