Network Devices

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Network Devices

• By Scott Burden Linnea Wong

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Hubs

• Intelligent hubs have console ports, to allow
  monitoring of the hubs status and port activity.
• Passive hubs just repeat any incoming signals to
  every port available, therefore does not act as a
  line repeater.
• Passive hubs just split signals to multiple ports
  but do not regenerate the signals, which means
  that they do not extend a cables length. They
  only allow two or more hosts to connect to the
  same cable segment.
• Active hubs regenerate signals.
• Hubs utilise star topology.

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Hub Pros Cons

• Advantages
• As an active hubs regenerate signals, it
  increases the distance that can be spanned by the
  LAN (up to 100 meters per segment).
• Hubs can also be connected locally to a maximum
  of two other hubs, thereby increasing the number
  of devices that can be attached to the LAN.
• Active hubs are usually used against attenuation,
  which is a decrease in the strength of the signal
  over distance.

• Disadvantages
• Bandwidth is shared by all hosts i.e. 10Mbs
  shared by 25 ports/users.
• Can create bottlenecks when used with switches.
• Have no layer 3 switching capability.
• Most Hubs are unable to utilise VLANS.

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Switches

• A switch is a multi-port bridge.
• It operates at OSI data link layer 2.
• It stores MAC addresses in an internal lookup
  table.
• Temporary switched paths are created between the
  frames source destination.
• Some Switches have limited layer 3 IP routing
  capabilities.
• Switches can be configured to use VLANS.
• Switches support spanning tree protocol to create
  resilient networks.

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Example Topology
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Transceiver Modules

• Connects to any Auxiliary Unit Interface port
  (AUI).
• Operates at OSI layer 1.
• Allows multiple media types to connect to an
  Ethernet device. i.e. fibre ST/SC,Co-ax cable,
  and UTP.

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Routers

• Routers are OSI network layer 3 devices
• Using interface modules can connect different
  layer 2 technologies e.g. Ethernet, FDDI, token
  ring etc
• Routers have the capability to interconnect
  network segments or entire networks (WANS/MANS).
• These devices examine incoming packets to
  determine the destination address of the data. It
  then examines its internal routing table to
  choose the best path for the packet through the
  network, and switches them to the proper outgoing
  port.

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Example Router Topology
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THE END!!