Network Topologies

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Network Topologies
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Point-to-Point Topology

• Point-to-point (PTP) topology connects two nodes
  directly together. The following examples are
  pure point to point links
• Two computers communicating via modems.
• A mainframe terminal communicating with a front
  end processor.
• A workstation communicating along a parallel
  cable to a printer.

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Star Topology

• The star topology is a popular method of
  connecting the cabling in a computer network. In
  a star, each device connects to a central point
  via a point-to-point link. Depending on the
  locical architecture used, several names are used
  for the central point includeing the following
• Hub
• Multipoint Repeater
• Concentrator
• Multi-Access Unit (MAU)

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Ring Topology

• The Ring Topology is a physical, closed loop
  consisting of point-to-point links. In the
  diagram you can see how each node on the ring
  acts as a repeater. It receives a transmission
  from the previous node and amplifies it before
  passing it on.

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Bus Topology

• In a Bus topology, all devices attach to the same
  transmission medium. The medium has a physical
  beginning and end.All buses are implemented using
  electrical cable, usually coax, and the ends of
  the cable must be terminated with a terminating
  resistor that matches the impedance of the cable.
  The terminating resistor prevents data
  reflections from coming across as data
  corruption. The bus is considered a multipoint
  system because all devices tap into the same
  backbone cable.

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Hybrid Topology

• The Hybrid topology scheme combines multiple
  topologies into one large topology. The hybrid
  network is common in large wide area networks.
  Because each topology has its own strengths and
  weaknesses, several different types can be
  combined for maximum effectiveness.

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Coaxial Cable
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UTP Cable
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Ethernet

• An older, common wiring system for Ethernet
  (10Base2) and (10Base5) uses coaxial cable in a
  linear bus topology. In the most common type of
  Ethernet, each node connects to the coax through
  a T-connector (BNC) that taps into the signals on
  the coaxial cable. The nodes both transmit and
  receive through the same connector. Therefore,
  10Base2 Ethernet is a logical as well as physical
  bus.

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Token Ring

• The adjacent figure shows the path that a
  transmission follows through the network.
  Starting at the hub, the signal travels through a
  pair of wires to the receive circuits on the
  nodes network interface. The receive circuit
  passes the signal to the transmit circuit, which
  repeats the signal on a separate pair of wires
  and sends the signal back to the hub.

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ARCnet

• ARCnet is wired in a star using coaxial cable.
  The diagram adjacent shows an extremely simple
  ARCnet using a single passive hub.