Networking 101 Basics

							   "Networking 101: Basics"



Jim Gogan
INLS184
    Introduction - Why network?
 Communicate with others close by
 Communicate with others far away
 Gain access to information not on your
  computer
 Share resources (software, peripherals)
              *ANS?
 LANs
 WANs
 MANs
 internets
 Internet
 Intranet
      Components of a LAN
 Cable
 Workstations/Servers
 Interface cards (NICs)
 Hubs/switches/etc.
 Peripherals
 Network protocols
                      Cable
   Types of Cables
    – Coaxial cable
    – Twisted pair
    – Fiber optics
   Wireless
       Cabling Topologies
 Daisy Chain
 Bus
 Ring
 Star
             Daisy Chain
 Simplest to do
 One device hooked to device after it
 If broken, all connections are lost
 Daisy Chain network example: original
  LocalTalk
                   Bus
 Packets move along a straight line
 Works like a trolley, must have bumpers at
  ends of lines
 Devices are connected through taps on the
  line
 As long as taps aren’t disconnected,
  network stays up
 Bus network example: Thin-net Ethernet
                  Ring
 Cable must form complete, unbroken ring
 Packets with presence of token (usually)
 If ring broken, all devices may go down
 Ring network example: Token Ring
                   Star
 Devices are connected along “arms” of the
  star
 Arms connected to central hub
 When disconnected, only that arm of the
  star is affected
 Star network example: 10BaseT Ethernet
            Workstations
 The computer on an individual’s desk
 May have its own local devices/peripherals
  as well as access to networked peripherals
                       Servers
 Workstation (often higher end) with specific
  functions
 Usually provides services:
    – File services
    – Web services
    – Email services
           Interface cards
 Connect individual devices to network
 Must match type of device and type of cable
     Hubs and Switches and
       Network Devices
 Depends on type of network installed
 More about these later …...
              Peripherals
 Accessory devices (printers, fax machines,
  backup devices, etc.)
 Originally connected thru workstations or
  servers, now directly network connected
 Originally dumb, now intelligent enough to
  do some real damage
                Protocols
 Common language among computers
 Analogous to addressing envelopes
 Many different protocols out there
 Different “layers” use different protocols
       Network Addressing
 Must be unique to each device
 A single physical device can have several
  network addresses
 Usually divided into two parts: network and
  node (both parts can be combined into one
  address)
 May be permanent (static) or temporary
  (dynamic)
                 Packets
 Way information moves across the wire
 Packets can carry data or protocol/control
  information only
 Difference between “packet” and “cell”
         How Networks Grow
 File sharing
 Application sharing
 Peripheral sharing
 Client/server applications
    – Email
    – WWW
   Multimedia applications
Dividing/Expanding Networks
   Why:
    – Too much traffic
    – Too many nodes
    – Distance limitations
   How:
    – Repeaters
    – Bridges
    – Routers
       Performance Terms
 Bandwidth
 Throughput
 Latency (delay)
 Jitter
 Loss
Other Aspects/Considerations
 Security
 Management
               Key Points
 Standards     =   Good!
 Simplicity    =   Good! (easy to develop)
 Ethernet      =   Good! (it’s simple)
 TCP/IP        =   Good! (it’s simple)