Business Data Communications

1
Business Data Communications

• 8/e, John Wiley Sons 2004, FitzGerald and Dennis

2
Organization of the Textbook (FD)

• Part 1 Introduction (Ch1)
• Part 2 Fundamentals (Ch2-5)
• Part 3 Networking (Ch6-10)
• Part 4 Network management (Ch11-13)

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Introduction to Data Communications

• Topic 1

4
Some Hot Topics in Data Communications

• Email Spamming
• 13 billion spam emails/day, 10 billion losses
  this year
• Worm/virus attacks
• W32/SirCam_at_MM (Mass Mailer Worm) Alert
• Blaster worm
• Hacking
• Great Global Grid (GGG)
• Web services
• Wi-Fi
• WiMAX

5
Outlines

• A brief history of data communications
• Moores law
• The Internet
• Network concepts

6
Data Communications

• Definitions
• Data Communications
• The movement of computer information from one
  point to another by means of electrical or
  optical transmission systems. (How about
  satellite system?)
• Such systems are often called data communications
  networks.
• Telecommunications
• Includes the transmission of voice and video as
  well as data.

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A Brief History of Telecommunications

• 1837 - Samuel Morse exhibited a working telegraph
  system.
• 1843 - Alexander Bain patented a printing
  telegraph.
• 1876 - Alexander Graham Bell, invented the first
  telephone.
• 1880 - first pay telephone
• 1915 - first transcontinental telephone service
  and first transatlantic voice connections.
• 1947 - transistor invented in Bell Labs
• 1951 - first direct long distance dialing
• 1962 - first international satellite telephone
  call
• 1968 - Carterfone court decision allowed non-Bell
  equipment to connect to Bell System Network
• 1970 - permitted MCI to provide limited long
  distance service in competition to ATT.
• 1984 - deregulation of ATT
• 1980s - public service of digital networks
• 1990s - cellular telephones commonplace

8
Phases of Telecommunications Development

• Telegraph Telephone (19th century)
• Satellite communications (1960s)
• Digital communications (1980s)
• Internet age (1990s)
• Wireless communications (1990s)
• 21st century?
• Trends From wired to wireless, from analog to
  digital, from voice communicating to data
  communicating

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The Invention of Telephone

• Who invented the telephone?
• Alexander Graham Bell?
• Elisha Gray's caveat, as it was filed in the
  United States Patent Office, February 14, 1876
• Elisha was a new immigrant, who did not have good
  English communication skills. The economic
  condition was too bad to have enough money to pay
  the patent fee.

10
Semiconductor Industry the foundation of IT

• Vacuum tube Early the 20th century (?)
• Transistor (Transfer resistor), 1947 at Bell Lab
  invented by John Bardeen, Walter Brattain, and
  Willian Shockley (Physics Nobel prize winner in
  1956)
• Integrated circuit, invented by Jack Kilby, TI,
  in 1959 (Physics Nobel prize winner in 2000)

11
Moores Law

• When 1965
• Who Gordon Moore, co-founder of Intel.
• Dr. Moore was preparing a speech and made a
  memorable observation. When he started to graph
  data about the growth in memory chip performance,
  he realized there was a striking trend.
• What Each new chip contained roughly twice as
  much capacity as its predecessor, and each chip
  was released within 18-24 months of the previous
  chip.
• An Analogy If this trend were applicable to
  airline industry, the plane would cost 500,
  weigh a few pounds, travel around the world in 20
  minutes.

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Analyses

• Moores minimum cost
• 1962 12 components/chip
• 1965 50 components/chip
• 1970 10 of the cost in 1965 per transistor
• 1975 65,000 components/chip
• The speed growth is faster than size reduction,
  because there has been a rapid increase in clock
  frequency.
• Kuzweil (1999) pointed out that the doubling of
  processing power started earlier
• 1908 (Hollerith Tabulator)
• 1911 (Monroe Calculator)
• 1946 (ENIAC)
• 1951 (Univac I)
• 1959 (IBM 7090)

13
CPUs Capacity Growth
2000
14
Internet, Intranet and Extranet

• The Internet a network of networks servicing the
  users worldwide
• Intranet an organization's private network that
  uses Internet technology
• Extranet The intranet that some of its functions
  are accessible to the organization's business
  partners

15
The Internet

• Three aspects of the Internet evolution
• Capacity growth
• Application and traffic growth
• Internet policy change

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Internet Capacity

• ARPANET (1969) The Internet was started by the
  U.S. Department of Defense as a network of four
  computers.
• - 1974, 62 hosts
• - 1983, 1000 hosts
• - 1989, decommissioned
• NSFNET (1986) Built up by National Science
  Foundation with a 3-tier structure
• - 1987, 10,000 hosts in the Internet, 1000 in
  BITNET
• - 1988, upgraded to T1 (1.544 Mbps).
• - 1991, upgraded to T3 (45Mbps)
• - 1995, decommissioned
• vBNS (1995) 622Mbps in 1995
• vBNS (now) 2.5 Gbps (or more)

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NSFNET
By 1991, the NSFNET's backbone network service
has been upgraded to T3 (45 Mbps) links
18
Internet Policy and deregulations

• Originally, commercial traffic was forbidden on
  the Internet, because the major portions of these
  networks were funded by the various national
  governments and research organizations.
• In the early 1990s, commercial networks began
  connecting into these networks, opening it to
  commercial traffic.

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Todays Internet
Abilene vBNS CANet 3
Figure 9-11 Gigapops and high speed backbones of
Internet 2/Abilene, vBNS, and CANet 3
20
vBNS Components
The vBNS is accessible to select application
sites through four NAPs in New York, San
Francisco, Chicago, and Washington, D.C. The
vBNS is mainly composed of OC3 /T3
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NAP

• Network access point (NAP)
• The NAP is defined as a high-speed network or
  switch to which a number of routers can be
  connected for the purpose of traffic exchange.
  NAPs must operate at speeds of at least 100 Mbps
  and must be able to be upgraded as required by
  demand and usage.
• The concept of the NAP is built on the FIX
  (Federal Internet eXchange) and the CIX
  (Commercial Internet eXchange), which are built
  around FDDI rings with attached Internet networks
  operating at speeds of up to 45 Mbps.

22
Some vBNS Facts (2001)

• Speed 2.5 Gbps (OC-48)
• Multi-protocol Label Switching (MPLS)
• 0.001 Packet loss and 100 availability
• both unicast and multicast
• IPv6 enabled
• Extends to Europe and Asia

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Abilene

• Abilene is an advanced backbone network that
  supports the development and deployment of the
  new applications being developed within the
  Internet2 community. Abilene connects regional
  network aggregation points, called gigaPoPs, to
  support the work of Internet2 universities as
  they develop advanced Internet applications.
  Abilene complements other high-performance
  research networks.

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Internet Hosts Growth
(Recent statistics) July 1999 56,218,000
Internet hosts January 2000 68,862,283 Internet
hosts July 2000 86,509,613 Internet
hosts January 2001 113,873,000 Internet hosts
(MIDS) Now ?
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Internet Addresses

• Anyone with access to the Internet can
  communicate with any computer on the Internet.
• Addresses consist of two parts, the computer name
  and its domain.
• computer.domain
• Each domain has an addressing board that assigns
  addresses for its domain.

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Internet Domain Names

• Country Codes
• CA (Canada)
• AU (Australia)
• UK (United Kingdom)
• DE (Germany)
• FR (France)
• CN (China)
• IN (India)
• MX (Mexico)

• Domain Names
• EDU
• COM
• GOV
• MIL
• ORG
• NET

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Components of a Network

• Server (or Host computer)
• Central computer in the network, storing data or
  software that can be accessed by the clients.
• Client
• The input/output hardware device at the other end
  
• of a communications circuit.
• Circuit
• The pathway through which the messages travel.
• Peer-to-peer networks
• Do not need a server or host, but are designed to
  connect similar computers which share their data
  and software with each other.

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Components of a Network
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Types of Networks

• Networks can be classified in many different
  ways. One of the most common is by geographic
  scope
• Local Area Networks (LAN)
• Backbone Networks (BNs)
• Metropolitan Area Networks (MANs)
• Wide Area Networks (WANs)

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Types of Networks
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Types of Networks

• Local Area Networks (LAN)
• A group of microcomputers or other workstation
  devices located in the same general area and
  connected by a common circuit.
• Covers a clearly defined small area, such as
  within or between a few buildings,
• Support data rates of 10 to 100 million bits per
  second (Mbps).

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Types of Networks

• Backbone Network (BN)
• A larger, central network connecting several
  LANs, other BNs, metropolitan area networks, and
  wide area networks.
• Typically span up to several miles.
• Support data rates from 64 Kbps to 45 Mbps.

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Types of Networks

• Metropolitan Area Network (MAN)
• Connects LANs and BNs located in different areas
  to each other and to wide area networks.
• Typically span from 3 - 30 miles.
• Supports data rates of 100 to 1000 Mbps.

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Types of Networks

• Wide Area Network (WAN)
• Connects BNs and MANs and are usually leased from
  inter-exchange carriers.
• Typically span hundreds or thousands of miles.
• Supports data rates of 28.8 Kbps to 2 Gbps.

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What is a Protocol?

• A standard that allows entities (i.e. application
  programs) from different systems to communicate
• Shared conventions for communicating information
• Includes syntax, semantics, and timing

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Standardized Protocol Architectures

• Vendors like standards because they make their
  products more marketable
• Customers like standards because they enable
  products from different vendors to interoperate
• Two protocol standards are well-known
• TCP/IP widely implemented
• OSI less used, still useful for
  modeling/conceptualizing

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Internet Standards

• Email related standards
• IMAP, POP, X.400, SMTP, CMC, MIME, binhex,
  uuencode
• Web related standards
• http, CGI, html/xml/vrml/sgml
• Internet directory standards
• X.500, LDAP
• Application standards
• http, FTP, telnet, gopher, wais
• Videoconferencing standards
• H.320, H.323, Mpeg-1, Mpeg-2

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Telecommunication Standards Organizations

• International Telecommunications Union -
  Telecommunication Standardization Sector
  (ITU-TSS). Formerly called the Consultative
  Committee on International Telegraph and
  Telephone (CCITT)
• International Organization for Standards (ISO).
  Member of the ITU, makes technical
  recommendations about data communications
  interfaces.
• American National Standards Institute (ANSI)
• Institute of Electrical and Electronics Engineers
  (IEEE)
• Internet Engineering Task Force (IETF)
• Electronic Industries Association (EIA)
• National Institute of Standards and Technology
  (NIST)
• National Exchange Carriers Association (NECA)
• Corporation for Open Systems (COS)
• Electronic Data Interchange -(EDI) of Electronic
  Data Interchange for Administration Commerce and
  Transport (EDIFACT).

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Internet Engineering Task Force
A protocol proposed by a vendor
IETF working group study the proposal
IETF issues a request for comment (RFC)
IETF reviews the comments
IETF proposes an improved RFC
The RFC becomes a proposed standard
The proposed standard becomes a draft standard
if two or more vendors adopt it