ppt of coaxial by sumedh007

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									Introduction To Networking

    Networking Media




                             Slide 1
Introduction

• Introduction
• Coaxial Cable
• Twisted-Pair Cable
• Fiber-Optic Cable
• Cable Design and Management
• Installing Cable
• Wireless Transmission
     • Characteristics of Wireless Transmission
     • WLAN Architecture




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 2
Introduction

• Just as highways and streets provide the foundation
  for automobile travel, networking media provide the
  physical foundation of data transmission
• Media are the physical or atmospheric paths that
  signals follow
• The first networks transmitted data over thick,
  heavy coaxial cables
• Today, data is commonly transmitted over a newer
  type of cable—one that resembles telephone cords,
  with their flexible outsides and twisted copper wire
  insides

 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 3
Coaxial Cable




                Slide 4
Coaxial Cable

• Coaxial cable (coax for short), was the foundation
  for Ethernet networks in the 1970s and remained a
  popular transmission medium for many years
• Coaxial cable consists of a central copper core
  surrounded by an insulator, a braided metal
  shielding, called braiding, and an outer cover,
  called the sheath or jacket




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 5
Coaxial Cable

• Data networks have primarily used two physical
  layer specifications to transmit data over coaxial
  cable:
     • Thicknet
     • Thinnet
• Thicknet (thickwire Ethernet)
     • The original Ethernet medium, Thicknet uses RG-8 coaxial
       cable, which is approximately 1-cm thick and contains a
       solid copper core
     • IEEE designates Thicknet as 10BASE-5 Ethernet.
     • The "10" represents its throughput of 10 Mbps, the "Base"
       stands for baseband transmission, and the "5" represents
       the maximum segment length of a Thicknet cable, which is
       500 meters

 Copyright(c)2006, Groove Systems. All Rights Reserved.     Slide 6
Coaxial Cable

• Thinnet (thin Ethernet)
     • A popular medium for Ethernet LANs in the 1980s, Thinnet
       uses RG-58A/U coaxial cable
     • Its diameter is approximately 0.64 cm, which makes it more
       flexible and easier to handle and install than Thicknet
     • Its core is typically made of several thin strands of copper
     • IEEE has designated Thinnet as 10BASE-2 Ethernet, with
       the "10" representing its data transmission rate of 10 Mbps,
       the "Base" representing the fact that it uses baseband
       transmission, and the "2" representing its maximum
       segment length of 185 meters (or roughly 200)




 Copyright(c)2006, Groove Systems. All Rights Reserved.       Slide 7
Coaxial Cable

• Coaxial cable is still used to setup a network that
  connects to the Internet through a broadband cable
  carrier like Shaw
• The cable that comes into a house from Shaw is RG-
  6 coaxial cable




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 8
Twisted-Pair Cable




                     Slide 9
Twisted-Pair Cable

• Twisted-pair cable consists of color-coded pairs of
  insulated copper wires, each with a diameter of 0.4
  to 0.8 mm
• Every two wires are twisted around each other to
  form pairs and all the pairs are encased in a plastic
  sheath




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 10
Twisted-Pair Cable

• Twisted-pair cable is the most common form of
  cabling found on LANs today
• It is relatively inexpensive, flexible, and easy to
  install, and it can span a significant distance
• Twisted-pair cable easily accommodates several
  different topologies, although it is most often
  implemented in star or star-hybrid topologies
• All twisted-pair cable falls into one of two
  categories: shielded twisted-pair (STP) or
  Unshielded twisted-pair (UTP)


 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 11
Twisted-Pair Cable

• Shielded twisted-pair cable consists of twisted
  wire pairs that are not only individually insulated,
  but also surrounded by a shielding made of a
  metallic substance such as foil
• STP use a braided copper shielding
     • The shielding acts as a barrier to external electromagnetic
       forces, thus preventing them from affecting the signals
       traveling over the wire inside the shielding
     • The shielding may be grounded to enhance its protective
       effects




 Copyright(c)2006, Groove Systems. All Rights Reserved.       Slide 12
Twisted-Pair Cable

• Unshielded Twisted-Pair cabling consists of one
  or more insulated wire pairs encased in a plastic
  sheath
• UTP does not contain additional shielding for the
  twisted pairs and both less expensive and less
  resistant to noise than STP




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 13
Twisted-Pair Cable

• To manage network cabling, you need to be familiar with the
  standards for use on modern networks:
     • CAT 3 (Category 3) - A form of UTP that contains four wire pairs
       and can carry up to 10 Mbps of data with a possible bandwidth of
       16 MHz.
     • CAT 4 (Category 4) - A form of UTP that contains four wire pairs
       and can support up to 16 Mbps throughput.
     • CAT 5 (Category 5) - A form of UTP that contains four wire pairs
       and supports up to 1000 Mbps throughput and a 100-MHz signal
       rate.
     • CAT 5e (Enhanced Category 5) - A higher-grade version of CAT
       5 wiring that contains high-quality copper, offers a high twist ratio,
       and uses advanced methods for reducing crosstalk. Enhanced CAT
       5 can support a signaling rate as high as 350 MHz, more than
       triple the capability of regular CAT 5.


 Copyright(c)2006, Groove Systems. All Rights Reserved.               Slide 14
Twisted-Pair Cable




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 15
Twisted-Pair Cable

• STP and UTP share several characteristics, the
  following list highlights their similarities and
  differences:
     • Throughput - STP and UTP can both transmit data at 10,
       100, and 1000 Mbps (1 Gbps), depending on the grade of
       cabling and the transmission method in use
     • Cost - STP and UTP vary in cost, depending on the grade of
       copper used, the category rating, and any enhancements.
       Typically, STP is more expensive than UTP because it
       contains more materials and it has a lower demand. High-
       grade UTP, however, can be very expensive.
     • Size and scalability— The maximum segment length for
       both STP and UTP is 100 m, or 328 feet, on 10BASE-T and
       100BASE-T networks. These accommodate a maximum of
       1024 nodes.

 Copyright(c)2006, Groove Systems. All Rights Reserved.     Slide 16
Twisted-Pair Cable

• Connector - STP and UTP use RJ-45 (Registered
  Jack 45) modular connectors and data jacks, which
  look similar to analog telephone connectors and
  jacks, and which follow the RJ-11 (Registered
  Jack 11) standard




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 17
Twisted-Pair Cable - 10BASE-T

• 10BASE-T (Ethernet) is a popular Ethernet
  networking standard that replaced the older
  10BASE-2 and 10BASE-5 technologies
• The "10" represents its maximum throughput of 10
  Mbps, the "Base" indicates that it uses baseband
  transmission, and the "T" stands for twisted pair,
  the medium it uses
• On a 10BASE-T network, one pair of wires in the
  UTP cable is used for transmission, while a second
  pair of wires is used for reception



 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 18
Twisted-Pair Cable - 10BASE-T

• The maximum distance that a 10BASE-T segment
  can traverse is 100 meters




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 19
Twisted-Pair Cable - 100BASE-T

• 100BASE-T (Fast Ethernet) enables LANs to run
  at a 100-Mbps data transfer rate, a tenfold increase
  from that provided by 10BASE-T, without requiring
  a significant investment in new infrastructure
• It also uses RJ-45 modular connectors
• Depending on the type of 100BASE-T technology
  used, it may require CAT 3, CAT 5, or higher UTP




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 20
Twisted-Pair Cable - 100BASE-T

• The maximum distance that a 100BASE-T segment
  can traverse is 100 meters




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 21
Twisted-Pair Cable - 1000BASE-T

• Because of increasing volumes of data and numbers of users
  who need to access this data quickly, even 100 Mbps has not
  met the throughput demands of some networks
• Ethernet technologies designed to transmit data at 1 Gbps are
  collectively known as Gigabit Ethernet
• 1000BASE-T is a standard for achieving throughputs 10 times
  faster than Fast Ethernet over copper cable
• The maximum segment length on a 1000BASE-T network is
  100 meters
     • It allows for only one repeater
     • Therefore, the maximum distance between communicating nodes
       on a 1000BASE-T network is 200 meters




 Copyright(c)2006, Groove Systems. All Rights Reserved.       Slide 22
Fiber-Optic Cable




                    Slide 23
Fiber-Optic Cable

• Fiber-optic cable contains one or several glass or plastic
  fibers at its core
• Data is transmitted via pulsing light sent from a laser or a
  light-emitting diode (LED) through the central fibers
• Surrounding the fibers is a layer of glass or plastic called
  cladding
• Outside the cladding, a plastic buffer protects the cladding and
  core
     • Because it is opaque, it also absorbs any light that might escape
• To prevent the cable from stretching, and to protect the inner
  core further, strands of Kevlar (an advanced polymeric fiber)
  surround the plastic buffer
• Finally, a plastic sheath covers the strands of Kevlar

 Copyright(c)2006, Groove Systems. All Rights Reserved.             Slide 24
Fiber-Optic Cable

• All fiber cable variations fall into two categories:
  single-mode and multimode




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 25
Fiber-Optic Cable - SMF (Single-Mode Fiber)

• SMF uses a narrow core through which light
  generated by a laser travels over one path,
  reflecting very little
• Because it reflects little, the light does not disperse
  as the signal travels along the fiber
     • This continuity allows single-mode fiber to accommodate
       high bandwidths and long distances




 Copyright(c)2006, Groove Systems. All Rights Reserved.     Slide 26
Fiber-Optic Cable - MMF (Multimode Fiber)

• MMF contains a core with a larger diameter than
  single-mode fiber over which many pulses of light
  generated by a laser or LED travel at different
  angles
• It is commonly found on cables that connect a
  router to a switch or a server on the backbone of a
  network




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 27
Fiber-Optic Cable

• Fiber is currently used primarily as a cable that
  connects the many segments of a network because
  of its reliability
• Fiber-optic cable provides the following benefits
  over copper cabling:
     • Nearly unlimited throughput
     • Very high resistance to noise
     • Excellent security
     • Ability to carry signals for much longer distances before
       requiring repeaters than copper cable
     • Industry standard for high-speed networking



 Copyright(c)2006, Groove Systems. All Rights Reserved.        Slide 28
Fiber-Optic Cable

• Fiber has proved reliable in transmitting data at
  rates that exceed 10 Gigabits (or 10,000 Megabits)
  per second
     • Its high throughput capability makes it suitable for network
       backbones and for serving applications that generate a
       great deal of traffic, such as video or audio conferencing
• Fiber-optic cable is the most expensive transmission
  medium
     • Not only is the cable itself more expensive than copper
       cabling, but fiber-optic NICs and hubs can cost as much as
       five times more than NICs and hubs designed for UTP
       networks


 Copyright(c)2006, Groove Systems. All Rights Reserved.       Slide 29
Fiber-Optic Cable

• With fiber cabling, you can use
  any of 10 different types of
  connectors
• Existing fiber networks typically
  use ST or SC connectors
• MT-RJ connectors are used on
  the very latest fiber-optic
  technology
• LC and MT-RJ connectors are
  preferable to ST and SC
  connectors because of their
  smaller size, which allows for a
  higher density of connections
  at each termination point


 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 30
Fiber-Optic Cable

• Depending on the type of fiber-optic cable used,
  segment lengths vary from 150 to 40,000 meters
• This limit is due primarily to optical loss, or the
  degradation of the light signal after it travels a
  certain distance away from its source
• Optical loss accrues over long distances and grows
  with every connection point in the fiber network




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 31
Cable Design and Management




                              Slide 32
Cable Design and Management

• In 1991, a Commercial Building Wiring Standard,
  also known as structured cabling, as released to
  describe uniform, enterprise-wide, multi-vendor
  cabling systems
• Structured cabling suggests how networking media
  can best be installed to maximize performance and
  minimize upkeep
• Structured cabling specifies standards without
  regard for the type of media or transmission
  technology used on the network



 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 33
Cable Design and Management




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 34
Cable Design and Management

• Entrance facilities
• The point at which a building's internal cabling plant
  begins
• The entrance facility separates LANs from WANs and
  designates where the telecommunications service
  carrier (whether it's a local phone company,
  dedicated, or long-distance carrier) accepts
  responsibility for the (external) wire
• The point of division between the service carrier's
  network and the internal network is also known as
  the demarcation point (or demarc)

 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 35
Cable Design and Management

• Backbone wiring
• The interconnection between telecommunications
  closets, equipment rooms, and entrance facilities
• On a campus-wide network, the backbone includes
  not only vertical connectors between floors, or
  risers, and cabling between equipment rooms, but
  also cabling between buildings
• On modern networks, backbones are usually
  composed of fiber-optic or UTP cable
• The cross connect is the central connection point for
  the backbone wiring

 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 36
Cable Design and Management

• Equipment room
• The location of significant networking hardware,
  such as servers and mainframe hosts
• Cabling to equipment rooms usually connects
  telecommunications closets




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 37
Cable Design and Management

• Telecommunications closet
• A "telco room" that contains connectivity for groups
  of workstations in its area, plus cross connections to
  equipment rooms
• Telecommunications closets typically house patch
  panels, punch-down blocks, hubs or switches, and
  possibly other connectivity hardware




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 38
Cable Design and Management

• A punch-down block is a panel of data receptors
  into which horizontal cabling from the workstations
  is inserted




• A patch panel is a wall-mounted panel of data
  receptors into which patch cables from the punch-
  down block are inserted
• Patch cables connect the patch
  panel to the hub or switch


 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 39
Cable Design and Management

• Horizontal wiring
• The wiring that connects workstations to the closest
  telecommunications closet
• The maximum allowable distance for horizontal
  wiring is 100 m
•




    Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 40
Cable Design and Management

• Work area
• An area that encompasses all patch cables and
  horizontal wiring necessary to connect workstations,
  printers, and other network devices from their NICs
  to the telecommunications closet
• A patch cable is a relatively short section (usually
  between 3 and 25 feet long) of cabling with
  connectors on both ends




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 41
Cable Design and Management

• Document your cabling plant!
• Be sure to include the locations, installation dates,
  lengths, and grades of installed cable
• Label every data jack, punch-down block, and
  connector
• Use color-coded cables for different purposes
     • For example, you might want to use pink for patch cables,
       green for horizontal wiring, and gray for vertical (backbone)
       wiring




 Copyright(c)2006, Groove Systems. All Rights Reserved.       Slide 42
Installing Cable




                   Slide 43
Installing Cable




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 44
Installing Cable

• There are two different methods of inserting UTP
  twisted pairs into RJ-45 plugs: TIA/EIA 568A and
  TIA/EIA 568B
• There is no difference between the standards, but
  have to be certain that you use the same standard
  on every RJ-45 plug and jack on your network, so
  that data is transmitted and received correctly




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 45
Installing Cable

• TIA/EIA 568A standard terminations




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 46
Installing Cable

• TIA/EIA 568A standard terminations




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 47
Installing Cable

• If you terminate the RJ-45 plugs at both ends of a
  patch cable identically, following one of the TIA/EIA
  568 standards, you will create a straight-through
  cable
• A straight-through cable is so named because it
  allows signals to pass "straight through" between
  terminations




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 48
Installing Cable

• There are times where you may want to reverse the
  pin locations of some wires
     • For example, when you want to connect two workstations
       without using a connectivity device or when you want to
       connect two hubs through their data ports
• This can be accomplished through the use of a
  crossover cable, a patch cable in which the
  termination locations of the transmit and receive
  wires on one end of the
   cable are reversed




 Copyright(c)2006, Groove Systems. All Rights Reserved.    Slide 49
Wireless Transmission




                        Slide 50
Wireless Transmission

• Networks that transmit signals through the
  atmosphere via infrared or radiofrequency (RF)
  waves are known as wireless networks or WLANs
  (wireless LANs)
• Wireless transmission is now common in business
  and home networks and are necessary in some
  specialized network environments
• In addition to infrared and RF transmission,
  microwave and satellite links can be used to
  transport data through the atmosphere



 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 51
Characteristics of Wireless Transmission

• Although wire-bound signals and wireless signals
  share many similarities, including the use of
  protocols and encoding, the nature of the
  atmosphere makes wireless transmission vastly
  different from wire-bound transmission
• The air provides no fixed path for signals to follow,
  signals travel without guidance
• The lack of a fixed path requires wireless signals to
  be transmitted, received, controlled, and corrected
  differently from wire-bound signals



 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 52
Characteristics of Wireless Transmission

• Wireless signals originate from electrical current traveling
  along a conductor
• The electrical signal travels from the transmitter to an
  antenna, which then emits the signal, as a series of
  electromagnetic waves, to the atmosphere
• The signal propagates through the air until it reaches its
  destination
• At the destination, another antenna accepts the signal, and a
  receiver converts it back to current




 Copyright(c)2006, Groove Systems. All Rights Reserved.    Slide 53
WLAN Architecture

• The most common form of WLAN relies on lower
  frequencies in the 2.4–2.4835 GHz band, more
  commonly known as the 2.4-GHz band, to send
  and receive signals
• This set of frequencies is popular for many modern
  communications services because it is unlicensed in
  the United States
     • That is, the FCC does not require users to register their
       service and reserve sole use of these frequencies




 Copyright(c)2006, Groove Systems. All Rights Reserved.        Slide 54
WLAN Architecture

• AD-Hoc WLAN




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 55
WLAN Architecture

• Infrastructure WLAN




 Copyright(c)2006, Groove Systems. All Rights Reserved.   Slide 56

								
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