ITEC 370

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• ITEC 370
• Network Media
• George Vaughan

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Sources for Slides

• Material in these slides comes primarily from
  course text, Guide to Networking
  Essentials,Tomsho, Tittel, Johnson (2007).
• Other sources are cited in line and listed in
  reference section.

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TCP/IP and OSI Models
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Cable Characteristics

• Bandwidth Bits per second
• Maximum Cable Length Length before signal is
  unintelligible due to attenuation.
• Maximum Number of Segments Maximum number of
  segments (including signal regeneration
  equipment) before signal is too late at
  destination.
• Maximum Number of Devices per Segment Devices
  also increase attenuation (insertion loss).
• Interference Susceptibility Electromagnetic
  Interference (EMI) and Radio Frequency
  Interference (RFI).
• Connection Hardware Cost, Complexity
• Cable Grade Cladding or Sheath Material, Fire
  Codes, Usable in walls or plenum.
• Bend Radius Degrees per feet
• Material Cost
• Installation Cost

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Boadband and Baseband Communication

• Baseband
• Uses a single frequency to transmit digital
  pulses.
• Half Duplex per strand (2 strands for Full
  Duplex).
• Bi-directional one strand can be used for
  sending and receiving.
• Repeaters and switches are used for signal
  regeneration.
• Used in Ethernet
• Broadband
• Analog Transmission
• More than one frequency can be on one strand
• A single strand can support Full Duplex
• One frequency is unidirectional 2 strands
  (Dual-Cable Broadband) or 2 frequencies
  (Mid-split broadband) needed for Full Duplex.
• Amplifiers used to strengthen signals.

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Cable Types - Coax

• Used by Cable TV
• No longer used in LANs
• Interference better than twisted pair, worse
  than fiber
• Used in early Ethernet Applications
• 10Base5 (10 Mbps, Baseband, 500 meter segments) -
  Thicknet
• 10Base2 (10 Mbps, Baseband, 200 meter segments) -
  Thinnet
• Used in Physical Bus Ethernet networks
• Cable Modem Applications
• 75 ohm, RG-6 (Radio Grade)
• 256 Kps up to 1 Mbps
• Shared resource more connections lower
  bandwidth

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Coaxial Cable (continued)Tomsho, Tittel, Johnson
(2007)
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Coaxial Cable in Cable Modem Applications
(continued)Tomsho, Tittel, Johnson (2007)
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Cable Types Twisted Pair

• Twisted Pair (TP) strand pairs are twisted
  around each other minimizes interference and
  crosstalk.
• Unshielded Twisted Pair (UTP)
• Ethernet 10BaseT (10 Mbps, Basedband, UTP)
  requires physical Star topology (Odom, 2006)
• UTP most popular LAN cable
• Also used in Phone Systems

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Twisted-Pair CableTomsho, Tittel, Johnson (2007)
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Cable Types Twisted Pair

• Shielded Twisted Pair (STP) similar to UTP,
  except that braided pair is contained in a foil.
• No standard exists for STP.
• UTP and STP usually use RJ-45 (Registered Jack)
  telephone connectors.
• RJ-45 contain 8 contacts, although, only 4 are
  used, 2 for transmit (/-) and 2 for receive
  (/-)
• 2 different standards for wiring an RJ-45
  connector TIA/EIA 58A and TIA/EIA 58B
• Cable Wiring Strategies (Odom, 2006)
• Straight Through Wiring
• Pins (1,2) -gt Pins (1,2) and Pins (3,6) -gt Pins
  (3,6)
• Used for connecting PCs to hubs or switches
• Crossover Wiring
• Pins (1,2) -gt Pins (3,6) and Pins (3,6) -gt Pins
  (1,2)
• Used for connecting PCs to PCs or switches to
  switches

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Twisted-Pair Cable (continued)Tomsho, Tittel,
Johnson (2007)
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Cable Types Fiber Optic

• Uses light rather than EM signals to transmit
  information.
• Not susceptible to EMI or RFI
• Does not broadcast or radiate EM signals
• Extremely secure to electronic eavesdropping.
• Very High Bandwidth 10 Gb/s and greater
• Maximum cable segments on the order of miles.
• More fragile, less flexible than copper.
• More expensive.
• Each strand passes signals in one direction.

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Fiber-Optic CableTomsho, Tittel, Johnson (2007)
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Fiber-Optic Cable (continued)Tomsho, Tittel,
Johnson (2007)
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Single and Multi-Mode Fiber

• Information on this slide comes from (Odom, 2006)
• Multi-Mode
• Used with LEDs
• LEDs spread light in multiple angles
• LED light doesnt travel as far as laser
• Thicker core to absorb angular LED light
• Single-Mode
• Used with Lasers
• Lasers dont spread light single direction
• Thinner core
• Laser light travels further than with LED source

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Cable Type Comparisons

• Comparison of cost and performance of different
  cable types (Tomsho, 2007)

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Cable Considerations

• Plan network to separate light/moderate users
  from heavy users.
• Plan network to separate local traffic from
  backbone traffic
• A mixture of TP connected by hubs which are then
  interconnected by coax or fiber give TP greater
  reach
• Need to consider existing cable plant.

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Structured Cabling

• Defines cable plant organization (TIA/EIA 568)
• Work Area work station environment, patch cables
  (lt6 meters).
• Horizontal Wiring cabling from work area to
  Telecommunications Closet (lt90 meters)
• Telecommunications Closet (TCs) patch panel,
  hubs, switches.
• Equipment Rooms servers, switches, routers
• Backbone Cabling that connects equipment rooms,
  TCs. Fiber often used.
• Entrance Facilities location where leased lines
  meet Enterprise network.

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Telecommunications ClosetTomsho, Tittel, Johnson
(2007)
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Wireless LANs (WLAN)

• Standards are defined by Institute of Electrical
  and Electronics Engineers (IEEE)
• IEEE 802.11 networking characteristics is similar
  to Ethernet (IEEE 802.3)
• Characteristics of 802.11(IEEE 802.11, n.d.)

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The Wireless World (continued)Tomsho, Tittel,
Johnson (2007)
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Wireless MAN The 802.16 StandardTomsho, Tittel,
Johnson (2007)

• One of the latest wireless standards, 802.16
  Worldwide Interoperability for Microwave Access
  (WiMax), comes in two flavors 802.16-2004
  (previously named 802.16a), or fixed WiMax, and
  802.16e, or mobile WiMax
• Promise wireless broadband to outlying and rural
  areas, where last-mile wired connections are too
  expensive or impractical because of rough terrain
• Delivers up to 70 Mbps of bandwidth at distances
  up to 30 miles
• Operates in a wide frequency range (2 to 66 GHz)

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References

• Tomsho, Tittel, Johnson (2007). Guide to
  Networking Essentials. Boston Thompson Course
  Technology.
• Odom, Knott (2006). Networking Basics CCNA 1
  Companion Guide. Indianapolis Cisco Press
• Wikipedia (n.d.). IEEE 802.11. Retrieved
  09/10/2006 from http//en.wikipedia.org/wiki/802.1
  1a
• Wikipedia (n.d.). OSI Model. Retrieved 09/12/2006
  from http//en.wikipedia.org/wiki/OSI_Model