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									    CHAPTER 5
Internet and LAN Technology
  5 Chapter Contents
     Section A: Network Building Blocks
     Section B: Local Area Networks
     Section C: Internet Technology
     Section D: Internet Access




Chapter 5: Internet and LAN Technology     2
  5                                         SECTION   A
           Section A: Network Building Blocks
     Network Advantages and Challenges
     Network Classifications
     Geographic Scope: PANs, NANs, LANs,
      MANs, and WANs
     Organizational Structure: Client/Server and
      Peer-to-Peer
     Physical Topology
Chapter 5: Internet and LAN Technology                3
  5                                      SECTION   A
           Section A: Network Building Blocks
     Network Links
     Analog and Digital Signals
     Bandwidth
     Communications Protocols




Chapter 5: Internet and LAN Technology             4
  5 Network Advantages and Challenges
     Sharing networked hardware can reduce costs
     Sharing networked hardware can provide access to
      a wide range of services and specialized peripheral
      devices
     Sharing networked software can reduce costs
     Sharing data on a network is easy
     Networks enable people to work together
      regardless of time and place


Chapter 5: Internet and LAN Technology                      5
  5 Network Advantages and Challenges
     Networks may be vulnerable to unauthorized
      access from many sources and locations
            – More vulnerable than standalone computers
     Wireless networks can be tapped from a
      “snooping” computer
     Networked computers are susceptible to an
      increasing number of worms, Trojan horses,
      and blended threats

Chapter 5: Internet and LAN Technology                    6
  5 Network Classifications




Chapter 5: Internet and LAN Technology   7
  5 Geographical Scope: PANs, NANs,
           LANs, MANs, and WANs
     Personal Area Network (PAN) – interconnection of
      personal digital devices
     Neighborhood Area Network (NAN) – connectivity
      spread over several buildings
     Local Area Network (LAN) – usually connects
      computers in a single building
     Metropolitan Area Network (MAN) – public high-
      speed network with range of about 50 miles
     Wide Area Network (WAN) – consists of several
      smaller networks & covers a large geographical
      area

Chapter 5: Internet and LAN Technology                   8
  5 Organizational Structure: Client/Server
           and Peer-to-Peer




Chapter 5: Internet and LAN Technology        9
  5 Physical Topology
     Arrangement of devices in a network
     Each connection point on a network is
      referred to as a node
     A bridge can connect two similar networks
     A gateway joins two dissimilar networks
            – Router




Chapter 5: Internet and LAN Technology            10
  5 Physical Topology
                                         In some networks, a hub is designed to
                                         broadcast data to workstations and
                                         peripherals.
                                         Tree topologies consist of multiple star
                                         networks connected into a bus
                                         configuration by a backbone.
                                         Each device connected to a network is
                                         referred to as a node.




Chapter 5: Internet and LAN Technology                                              11
  5 Physical Topology




                             A router joins two or more networks.

Chapter 5: Internet and LAN Technology                              12
  5 Network Links
     Wired network
            – Twisted-pair cable
                   • Shielded reduces
                   signal noise
            – Coaxial cable
            – Fiber-optic cable
                   • Does not conduct
                   electricity
     Wireless network
            – RF signals (not aimed in a single direction)
                   • Signals sent and received by a transceiver
            – Microwaves (aimed in single direction)
            – Infrared light

Chapter 5: Internet and LAN Technology                            13
  5 Analog and Digital Signals




Chapter 5: Internet and LAN Technology   14
  5 Bandwidth
     The transmission capacity of a
      communications channel
            – High-bandwidth channel (broadband)
                   • Cable TV
                   • DSL
            – Low-bandwidth channel (narrowband)
                   • Telephone system




Chapter 5: Internet and LAN Technology             15
  5 Communications Protocols
     Rules for efficiently transmitting data from one
      network node to another
            – Handshaking used to negotiate communications protocol
            – Dividing messages into
              packets
            – Affixing addresses to
              packets
            – Initiating transmission
            – Regulating the flow of data
            – Checking for transmission errors
            – Acknowledging receipt of transmitted data

Chapter 5: Internet and LAN Technology                                16
  5 Communications Protocols
     A packet is a “parcel” of data that is sent
      across a computer network
            – Packet switching technology vs. circuit-switching
              technology
                   • Voice over IP (VoIP)




Chapter 5: Internet and LAN Technology                            17
  5                                      SECTION   B
           Section B: Local Area Networks
     LAN Standards
     Ethernet
     Wi-Fi
     HomePNA and HomePLC Networks
     Installing a LAN
     Using a LAN

Chapter 5: Internet and LAN Technology             18
  5 LAN Standards
     LAN Technologies are standardized by the
      IEEE
            – ARCnet
            – Token Ring technology
            – FDDI
            – Ethernet
            – Wi-Fi



Chapter 5: Internet and LAN Technology           19
  5 Ethernet
     Simultaneously broadcasts data packets to
      all network devices
            – IEEE 802.3
            – CSMA/CD protocol




Chapter 5: Internet and LAN Technology            20
  5 Ethernet

                                         On an Ethernet, data
                                         travels on a “first come, first
                                         served” basis. If two
                                         workstations attempt to
                                         send data at the same time,
                                         a collision occurs.
                                         That data must be resent.

                                         CLICK TO START




Chapter 5: Internet and LAN Technology                                     21
  5 Ethernet
     Varies in speed from 10 Mbps to 10 Gbps
     An Ethernet card is designed to support the
      Ethernet protocols
     Ethernet hubs link workstations via cables
            – Uplink port




Chapter 5: Internet and LAN Technology              22
  5 Wi-Fi
     Wireless networking technologies that are
      compatible with Ethernet




Chapter 5: Internet and LAN Technology            23
  5 Wi-Fi
     WEP (Wired Equivalent Privacy) encrypts
      data traveling over wireless networks
     Equipment required for a wireless
      network
            – Wi-Fi card
            – Wireless access point
     Bluetooth is a short-range
      wireless network technology

Chapter 5: Internet and LAN Technology          24
  5 HomePNA and HomePLC Networks
     HomePNA networks utilize existing telephone
      wiring to connect network devices
            – Special NICs and cables are required
     HomePLC networks transmit data over power
      lines as low-frequency radio waves




Chapter 5: Internet and LAN Technology               25
  5 Installing a LAN




                                         CLICK TO START


Chapter 5: Internet and LAN Technology                    26
  5 Using a LAN
                                         In this drive mapping
                                         example, a server’s drive
                                         C is mapped as drive F
                                         by a workstation.
                                         After the mapping is complete,
                                         the server’s hard disk appears
                                         in the workstation’s directory as
                                         drive F and can be used just as
                                         though it were a drive
                                         connected directly to the
                                         workstation.

                                         CLICK TO START




Chapter 5: Internet and LAN Technology                                       27
  5 Using a LAN
     You can allow other
      network users to view
      and edit files in the
      folders you’ve
      designated as shared




Chapter 5: Internet and LAN Technology   28
  5 Using a LAN
     The Network Connection tool helps you
      troubleshoot connection problems




Chapter 5: Internet and LAN Technology        29
  5                                         SECTION   C
           Section C: Internet Technology
     Background
     Internet Structure
     ISP Infrastructure
     Internet Protocols
     IP Addresses
     Domain Names

Chapter 5: Internet and LAN Technology                30
  5 Background
      The Advanced Research
       Projects Agency designed
       ARPANET
      The Internet has an
       estimated 200 million
       nodes and 500 million
       users today
      Network Service Providers
       supply ISPs with access to
       high-speed transmission
       lines that form the
       backbone of the Internet


Chapter 5: Internet and LAN Technology   31
  5 Internet Structure




Chapter 5: Internet and LAN Technology   32
  5 Internet Structure
     Ping is used to find out whether a site is up
      and running
            – Reports latency which is elapsed time for round-
              trip message
     The Traceroute utility records a packet’s path




Chapter 5: Internet and LAN Technology                       33
  5 ISP Infrastructure




Chapter 5: Internet and LAN Technology   34
  5 Internet Protocols
     TCP and IP serve as the primary protocols
      responsible for message transmission on the
      Internet




Chapter 5: Internet and LAN Technology              35
  5 IP Addresses
     IP addresses are addresses that identify
      computers on the Internet. All machines will
      have EITHER a static or dynamic address to
      access the internet.
            – Static IP address
            – Dynamic IP address




Chapter 5: Internet and LAN Technology               36
  5 Domain Names
     Easy-to-remember names for Internet
      servers
            – Ends with an extension that indicates its top-level
              domain
     Every domain name corresponds to a unique
      IP address
            – Domain Name System
     ICANN coordinates technical management of
      the Internet’s Domain Name System

Chapter 5: Internet and LAN Technology                          37
  5 Domain Names
           The domain name system is based on
           a distributed database rather than one
           centralized computer. You do not need
           a domain name to simply access the
           Internet.




Chapter 5: Internet and LAN Technology              38
  5 Domain Names
                                         The first step in registering
                                         a domain name is to find out
                                         whether the name is currently
                                         in use or reserved for future
                                         use. If a domain name is not
                                         available, consider using a
                                         different top-level domain,
                                         such as biz instead of com.
                                         After you’ve found an
                                         available domain name you
                                         like, you can continue the
                                         registration process by filling
                                         out a simple online form.

                                         CLICK TO START


Chapter 5: Internet and LAN Technology                                     39
  5                                      SECTION   D
           Section D: Internet Access
     Dial-up Connections
     Cable Internet Service
     DSL, ISDN, and Dedicated Lines
     Wireless Internet Services
     LAN Internet Access
     Mobile Internet Access
     Internet Connection Roundup

Chapter 5: Internet and LAN Technology             40
  5 Dial-up Connections
     Uses POTS to transport data between your
      computer and your ISP
     A modem converts digital signals from your
      computer into analog signals that can travel
      over telephone lines, and vice versa
            – Modulation / Demodulation




Chapter 5: Internet and LAN Technology               41
  5 Dial-up Connections
     Modems are still
      required, despite digital
      telephone technology
     Modem speed is
      measured as baud rate
     Many Internet
      connection methods
      provide faster
      downstream
      transmission rates than
      upstream rates

Chapter 5: Internet and LAN Technology   42
  5 Cable Internet Service




Chapter 5: Internet and LAN Technology   43
  5 Cable Internet Service
     Cable modems convert your computer’s
      signal into one that can travel over the CATV
      network
     Always-on connection
     Neighborhood network




Chapter 5: Internet and LAN Technology                44
  5 DSL, ISDN, and Dedicated Lines
     DSL is a high-speed, digital, always-on
      Internet access technology that runs over
      standard telephone lines carrying data and
      voice
            – DSLAM
            – Most DSL installations require service
              technicians
                   • DSL modem



Chapter 5: Internet and LAN Technology                 45
  5 DSL, ISDN, and Dedicated Lines
     ISDN connections are slower than DSL and
      cable Internet service, but faster than dial-up
            – ISDN terminal adapter connects a computer to a
              telephone wall jack and converts signals to travel
              over ISDN connection
     T1, T3, and T4 lines are leased from the
      telephone company, and offer fast, high-
      capacity data transmission. These provide
      many of the links on the Internet backbone.
Chapter 5: Internet and LAN Technology                         46
  5 Wireless Internet Service
     Direct satellite service (DSS)
     Only alternative to dialup in many rural areas




Chapter 5: Internet and LAN Technology             47
  5 Wireless Internet Service
     Fixed wireless Internet service broadcasts
      RF signals in order to offer Internet access to
      large areas
            – WiMAX
            – Wireless service providers are usually local or
              regional businesses




Chapter 5: Internet and LAN Technology                          48
  5 LAN Internet Access
     Cost-effective way to share one Internet
      connection among several computers
     To establish LAN Internet access, you need:
            – An operational wired or wireless LAN
            – A router or a hub with router capabilities
            – A high-speed Internet connection, such as DSL,
              ISDN, or cable Internet
            – A modem that corresponds to your Internet
              connection type
Chapter 5: Internet and LAN Technology                         49
  5 Mobile Internet Access
     A Wi-Fi hotspot is a wireless broadband
      Internet service offered in a public location
            – WISP
     WAP is a communications protocol that
      provides Internet access from handheld
      devices




Chapter 5: Internet and LAN Technology                50
  5 Mobile Internet Access
     Handheld device services include:
            – Short message service (SMS)
            – Multimedia messaging (MMS)
            – Music fingerprinting
            – Games
            – City guides
            – E-mail
            – News, sports, stocks, and weather

Chapter 5: Internet and LAN Technology            51
  5 Mobile Internet Access
     Cellular service options




Chapter 5: Internet and LAN Technology   52
  5 Internet Connection Roundup




Chapter 5: Internet and LAN Technology   53
CHAPTER 5 COMPLETE
  Internet and LAN Technology

								
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